# What is this weird RTA saying about my sub?



## mooch91 (Apr 6, 2008)

All,

First let me start by saying, "I'm tired". I've been tuning, measuring, adjusting my very simple system for better than 5 years now and it's consuming me. It's actually just about at the point where I'm about to pack it in and give up this hobby. I could really use some help. Details of my system in my sig, but sub is the JL shallow 13TW5 in a 0.8 cu ft sealed enclosure. Sub amp is a JL 500/1. Front stage is Pioneer TS-C720PRS powered at 150x2 by a JL 300/4.

I've been RTA'ing my overall system response and finally have the high end where I want it. But I've never been able to fix the low end. My sub always seemed to be "not enough" or "too much", no matter what level or crossover I selected. My RTA has always shown a dip around 50-60 Hz and a peak in the 80-100 Hz range. I can never correct both. Usually the dip remains and the peak gets bigger or smaller.

Tonight I decided to run some experiments with the RTA. Ran pink noise through only the sub with a very high (200 Hz/24) LP crossover and this is what I got:









WTF is wrong with this picture? The curve shows almost a 10 dB rise from 50-100 Hz? Is this real output from the speaker or some sort of harmonics/resonance from the enclosure or environment? It's unlike anything I've seen or would have expected from a sealed subwoofer installed in an enclosure built to manufacturer's specs.

Then I tried three more conventional crossover settings to visualize the response (63/70/80):









Similarly awful from a linearity perspective. That rise from 50-100 Hz in the previous plot becomes a shelf with a sharp drop-off when crossed lower. Hardly the roll-off I would have expected from a sharp 24 db/oct crossover at these three points. 

My conclusion from this experiment is that the challenge I'm facing integrating a non-linear sub with a weak midbass is that 50-100 Hz rise (which becomes a 60-100 Hz shelf in the crossed response) is not correctable when I try to integrate the two.

Final response (63/24 crossover) is as follows (yellow) showing the contribution from the sub (purple):









That dip sounds exactly as it looks - not enough response at 60 Hz and any attempt to improve it by increasing crossover or EQ'ing has little effect and generally increases the 80-100 Hz hump to an objectionable level. I can't drop the crossover on the sub because I can't get a normal roll-off and I don't have enough from my mids to blend the two at a low crossover anyway.

Any idea what might be going on? I'm convinced I'm wasting my time with any more tuning until I can better understand this anomaly.

Thanks in advance...


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## 11blueGTI (Apr 24, 2011)

Either your sub is totally overpowering everything else or your mic is broken.


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## Ray21 (Oct 19, 2009)

I think the overall curve you have in the final looks decent albeit a bit bass heavy. 

I prefer this type of curve for my bass, which it looks you can get close to:









Here's the thread on the hard-knee house curve:
On Minimal EQ, Target Levels, and a Hard-Knee House Curve (long) - Home Theater Forum and Systems - HomeTheaterShack.com


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## Justin Zazzi (May 28, 2012)

Hi mooch91,

I hear your frustration. The RTA is a very powerful tool but there are just enough settings and nuances to ensure that the results can be nearly useless unfortunately. Lets double check a few things before narrowing down to the fine details:

-What microphone(s) and preamplifier are you using?
-Where did you get the calibration file for your microphone(s)?
-Can you use anything higher than 1/3 octave smoothing in TrueRTA?
-I see you are using L+R mode for measurement, do you have two microphones?
-Are you using any EQ in the screenshots, and if so, can you say what you are using?

Assuming all your testing gear is setup correctly and your subwoofer really is peaky around 100hz, one way to compensate is to cut with an EQ at roughly the same frequency to bring that huge peak more inline with the rest of the response. However it is really hard to see what is happening with 1/3 octave smoothing and more resolution would be nice. If you have not purchased a higher version of TrueRTA, I know that RoomEQWizard (free) has a very high resolution RTA function that would be better for this. Look at bikinpunk's thread for information on how to use it below:

http://www.diymobileaudio.com/forum...44399-rta-walkthrough-usage-thread-video.html

-J


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## Hanatsu (Nov 9, 2010)

60Hz is a common problem frequency. Most likely a mode related to the dimensions of your car. I have a cancellation there in my car as well. Try measure with sine sweeps (RoomEQ is good) and check decay/waterfall graphs and see how the plot looks decayed in time. This will show you if it's a room mode.

Sent from my Samsung Galaxy 3 via Tapatalk.


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## highspeed (May 4, 2012)

It's a long shot but have you tried moving the box to see how it might change the sound? I wonder if loading the sub as close as you can to the drivers side door would help. And facing towards the back. Obviously you couldn't use it that way but it might shed light on the path forward. If you know a shop that might allow you to drop in different woofers of different sizes it might also shed some light.
Sorry for all your troubles with this. I had a JL Stealthbox in my 2003 4runner with similar issues.


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## mooch91 (Apr 6, 2008)

Wow, thanks for the great thoughts guys! I'm going to try to respond one by one with some comments on things I have done already and which I can try rather easily. Hang tight and thanks again...


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## mooch91 (Apr 6, 2008)

Jazzi said:


> Hi mooch91,
> 
> I hear your frustration. The RTA is a very powerful tool but there are just enough settings and nuances to ensure that the results can be nearly useless unfortunately. Lets double check a few things before narrowing down to the fine details:
> 
> ...


Thanks Jazzi.

Microphone is the EMM-6 and pre-amp is the M-AUDIO MobilePre. Calibration file came from the manufacturer. I'm fairly confident it's not the mic - I've measured other systems, including my home theater, and I don't see the same effects.

I can measure up to 1/24 in True RTA, but I've always looked at it at 1/3 because of the granularity of the EQ. I can try to get some 1/24 plots to look at.

I'm actually only using single-channel measurement. The L+R is a result of the last measurement I made which was to send the head unit output direct to the sound card to see how flat the output was (or the sound card was) - it ended up flat from 20-20000.

Yes I'm using EQ on the front L+R channels, but nothing on the sub. I currently have an Eclipse EQ2102 in line with my front channels to help smooth out a very rocky response at the high end. The sub channel bypasses the EQ. The lowest band adjusted is in the 200 range, I believe. 

My options for adjusting just that sub peak are a little more limited, at least if I'm to follow the principle that cutting is better than boosting. If I run the sub channel through the EQ as well, any adjustments made at 100 will draw down my front channels too, which are already weak in the midbass department. I have a PEQ on the sub amp, but it allows for boost only which may be the only other option I have. 

Some things I think I can try from your commentary:

Take some measurements at 1/24 octave.
Try to reduce the 100 Hz peak with EQ connected to and influencing the sub channel alone.

Thanks again!


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## mooch91 (Apr 6, 2008)

11blueGTI said:


> Either your sub is totally overpowering everything else or your mic is broken.


Thanks 11blueGTI.

I'm thinking the mic is good based upon the response I see with other systems as well as my home theater.

Overpowering? I think I like about a 20 dB difference between my lowest sub-bass and my midrange for sure (which I've heard is not uncommon in the car to have such a difference). I know I'm trying to offset some significant engine noise from my diesel (especially around 50 - 60 Hz, which I've measured).

Thanks again for the ideas!


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## Hanatsu (Nov 9, 2010)

You need better resolution as stated. 1/12 at least (talking about the measurement). Results might be misleading otherwise.

Sent from my Samsung Galaxy 3 via Tapatalk.


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## Justin Zazzi (May 28, 2012)

mooch91 said:


> Thanks Jazzi.
> 
> Microphone is the EMM-6 and pre-amp is the M-AUDIO MobilePre. Calibration file came from the manufacturer. I'm fairly confident it's not the mic - I've measured other systems, including my home theater, and I don't see the same effects.
> 
> ...


I am using that microphone and one of M-audio's preamplifiers as well. Good stuff.

You should not have to take new measurements to view the higher resolution graphs. Just open a saved plot, and change to a higher resolution. Violla.

For the sake of eliminating variables, within TrueRTA make sure you are only using the Left channel instead of L+R. If you had a loopback cable in place and used L+R, that would give you all kinds of terrible readings. I think you have a good idea of how your gear works and would see that, but just to make sure ....

Yes it is usually best to cut rather than boost. If the null (valley) around 60hz is caused by the geometry of your car, then trying to boost that region will only result in giving your woofer more power or reaching xmax faster without any significant difference in output at that frequency. So instead of boosting that region, the best likely option is to cut the peak at 100hz.

If your EQ options are severely limited and you cannot find a way to do it, we might be able to help you come up with something if you post a list of your gear and how it is connected.

-J


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## Justin Zazzi (May 28, 2012)

Cajunner brings up an excellent point. Make sure all of your electronics are set to flat when you make these measurements for the sub. All crossovers disabled, all "bass boost" or other enhancements set to off or zero. Sometimes the simple things are the ones that get overlooked.

-J


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## james2266 (Sep 24, 2009)

I have almost the exact same curve problems as this actually. What vehicle is this anyway? Not a Rav4 by chance?  Anyways, a little experiment for you that I tried that told me this was a nasty room mode that ran the entire width of the cabin right smack where the front passengers sit. Try taking readings from the back seat or anywhere else really. Back seat was just easy for me. If the dip at 60 Hz goes away then it is likely a room mode. I am told you can do two things for a room mode, move the sub and/or midbasses or add more drivers. I am trying to conquer my problem with a larger midbass that should be able to better play these frequencies. I am getting them put in this evening so we'll see if the plan works or not.


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## ErinH (Feb 14, 2007)

My first suggestion would be to get in the car and play tones to see if the data matches what you hear. This will rule out the measurement setup. 

After that, measure the box in free field. Place the mic in the ground about 2ft away from the sub. Sweep the sub and get the response. Make sure to do this outside away from reflective boundaries. OR measure the sub with the mic a couple inches from the cone. Low volume. 

Doing this will tell you exactly what the sub is doing and what the car is doing. Then you'll be able to better target the problem.


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## mooch91 (Apr 6, 2008)

cajunner said:


> I'd turn off the amp crossovers, remove the EQ and run the deck's sub out into the /500.
> 
> using the parametric on the deck, adjust the peak at 80 hz using a narrow setting, and put the RTA back in, and see what happens.
> 
> ...


The first unfiltered sub plot is almost exactly as you suggested above. The crossover is high (I have a plot with no crossover and it's very similar, the roll-off is just a bit higher), it is not EQ'ed, and it's running direct from the deck (it's the full-range output as opposed to the sub output, but I've used a line connection to my RTA to confirm this output is flat) with nothing in between.

You're right: the deck has a three-band PEQ (in addition to the 7 house curves), the sub amp has a single band PEQ with boost only, and I have the 31-channel EQ that is connected to the front channels only.

I do feel like I've got a lot of options to try to fix this, but they are not independent enough to not create some very unconventional approaches to EQ. I can do a high Q (up to 4) PEQ boost at 60 on just the sub amp, as noted and I can do a high Q (up to 2) PEQ cut at 100 through the deck that will affect both the front and sub channels. I think there's going to be some overlap that might create some issues at 40-50, 80, and 125, but it's worth a shot.

I initially thought the roll-off didn't look natural, and I haven't done the math to see what a 24 db/oct roll-off would look like when applied to the unfiltered sub response, but I don't think it's that unnatural when you see how oddly the sub response rises between 60 and 100 Hz. But I can do one thing to rule out more of the electronics: I can use the crossover in the head unit instead of the amp to confirm a similar response.

I will add one more point of information - the sub amp has behaved flaky in the past. There have been occasions while RTA'ing where I just lose output to the sub or get a bit of scratching noise through the sub. Perhaps there is something more serious going on inside where it's creating the unusual response I'm seeing, but I think the only way I'd be able to confirm that is to change out the amp which is not an option at the moment. Or maybe I can find a way to scope the output...

So three things I can try from your recommendations include:

Use the JL sub amp PEQ (with high Q = 4?) to boost 60 Hz by a bit and RTA again to observe change.
Use the Kenwood head unit PEQ (with high Q = 2 which is max?) to drop 80-100 Hz by a bit and RTA again to observe change.
Low pass cross at head unit instead of amp, RTA again, and compare to curves obtained with xover at amp to rule out crossover issues in the amp.

Thanks cajunner!


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## mooch91 (Apr 6, 2008)

james2266 said:


> I have almost the exact same curve problems as this actually. What vehicle is this anyway? Not a Rav4 by chance?  Anyways, a little experiment for you that I tried that told me this was a nasty room mode that ran the entire width of the cabin right smack where the front passengers sit. Try taking readings from the back seat or anywhere else really. Back seat was just easy for me. If the dip at 60 Hz goes away then it is likely a room mode. I am told you can do two things for a room mode, move the sub and/or midbasses or add more drivers. I am trying to conquer my problem with a larger midbass that should be able to better play these frequencies. I am getting them put in this evening so we'll see if the plan works or not.


james2266,

Not a Rav 4, but a crew cab pickup. Probably not very different from an interior dimension perspective. One thing I can say is that the bass seems to "ring" when I'm sitting in the back seat and measuring. I always assumed that was because I was sitting closer to the sub and output was higher.

I can definitely try something from your recommendations to gather some more data to confirm a room mode:

Take some measurements of the sub frequency response from different locations in the truck to see if/how they change.


Thanks!


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## mooch91 (Apr 6, 2008)

Jazzi said:


> You should not have to take new measurements to view the higher resolution graphs. Just open a saved plot, and change to a higher resolution. Violla.


Thanks again Jazzi.

I thought I did an experiment some time back to compare TrueRTA results obtained in 1/24 octave directly vs. those obtained at 1/3 octave and then switched back to 1/24. I have some recollection that they looked a little different which led me to believe that some granularity was lost when switching resolution _after_ taking the measurement. I will try again just to compare.


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## mooch91 (Apr 6, 2008)

bikinpunk said:


> My first suggestion would be to get in the car and play tones to see if the data matches what you hear. This will rule out the measurement setup.
> 
> After that, measure the box in free field. Place the mic in the ground about 2ft away from the sub. Sweep the sub and get the response. Make sure to do this outside away from reflective boundaries. OR measure the sub with the mic a couple inches from the cone. Low volume.
> 
> Doing this will tell you exactly what the sub is doing and what the car is doing. Then you'll be able to better target the problem.


Thanks Erin. 

I've always struggled with using test tones because I have a hard time correlating what I hear with what I see in the frequency response plot when I take in to consideration the sensitivity of human hearing at different frequencies. If I hear a peak or a dip, for example, how do I determine if it is a result of something in my frequency response, a function of the sensitivity of my ears at that frequency, or a combination of both?

I guess, logically, since the shape of my target output curve is generally consistent with the sensitivity plots I've seen for human hearing, one would probably expect that all tones from 20 - 200 would sound approximately the same and I shouldn't expect any sharp peaks or dips?


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## subwoofery (Nov 9, 2008)

Suggest you use a combination of HU Xover and Amp Xover. 

Try to set your Amp's Xover to 80Hz (believe the slope is 24dB) and set your HU's Xover to 100Hz with a 12dB/oct slope (also try 24dB/oct slope)
Might need to reset your polarity or your T/A to blend with your midbass...

Kelvin


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## mooch91 (Apr 6, 2008)

I've been looking at a lot of information over the past couple of days and one thing that caught my eye that I wasn't aware of were some of the features from REW that don't exist in TrueRTA.

You guys have me convinced that it's OK to get a little crazy with my EQ as a potential solution to this problem. So I wanted to predict the outcomes a little better than trying, measuring, and listening (it's too cold out to be doing that!).

I found the EQ function in REW and love it.

I applied a PEQ boost of +3 db with a Q=2 at 60 Hz (which I can with the PEQ on the sub amp), a PEQ cut of -3 db with a Q=2 at 100 Hz (through the head unit), and a PEQ boost of +1 dB with a Q=4 (guessing this is the bandwith of the Eclipse EQ) at 125 Hz (through the equalizer).

Voila!










Instant fix, on paper at least. I'm going to try it out and measure tonight to see what happens.


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## mooch91 (Apr 6, 2008)

I don't want to get too excited just yet, but I started with the exact PEQ treatment I described above (this was the easy thing to try), and:









Smooth...

With the truck parked it sounds real good. Strong bass, full, but not boomy and not obnoxious in the midbass region. No mechanical sounds like I was getting at times before. A blend that I've never really been able to achieve.

The real test will be behind the wheel tomorrow when the engine noise is present too. 

Stay tuned...


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## mojozoom (Feb 11, 2012)

Is it tomorrow yet? I'm excited to hear how this all turned out....


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## mooch91 (Apr 6, 2008)

Guess I didn't realize I couldn't edit my posts after 72 hours. I accidentally moved the images and thought the links would follow. Anyway, *here's the three images from my first post, in order*:


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## mooch91 (Apr 6, 2008)

mojozoom said:


> Is it tomorrow yet? I'm excited to hear how this all turned out....


It's the day after tomorrow, but better late than never!

I actually only had about 15 minutes behind the wheel yesterday. Not enough time to try a big sampling of all of my music collection, but what I did play sounded very good so far.

I have historically found that my bass sounds very different when the truck is sitting and off than it does when it's running and moving. I've measured major noise peaks at 40 - 60 Hz due to the diesel engine. When I played it yesterday, bass remained pretty full across all of the selections that I played. But balanced. I did not find myself constantly looking to adjust any frequencies, nor did I find myself asking, "what's that unnatural sound". I'm thinking now that it's balanced, I could almost turn the overall sub level down by a slight bit.

Hard to believe that those seemingly minor peaks and valleys on the RTA could have such an impact on the overall transition between the two regions. MY guess is that when the transition is as big as the one I have (20 dB), that it's even more important the transition remain as smooth as possible.

So far, so good! I should be back in the driver's seat of this truck either tomorrow or Monday and will report some more.

Thanks to everyone, I feel a bit re-energized!


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## mooch91 (Apr 6, 2008)

cajunner said:


> The sharp point on your low pass slope RTA doesn't look like a natural response, it looks more like something is defective in your electronics somewhere.


I tinkered with REW and was able to apply a 24 db/oct low-pass (I think, I still haven't gotten the REW filters quite straight) to the curve and it did end up looking very similar to the filtered response I measured.


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## mooch91 (Apr 6, 2008)

I still haven't been behind the wheel very much so I haven't had a chance to judge if problem is "solved".

I did spend some time behind the RTA today just to tinker with some of the suggestions you guys made.

One suggestion was to look at the RTA with a little more granularity, 1/24 octave instead of 1/3 octave.

The result is a little bit weird to me - some big swings in frequency response (10 dB) across all of the sub frequencies. Is this to be expected, or could it be indicative of a bigger problem I might be dealing with? 

Here's the 1/24 plot:









And the 1/3 smoothed version:


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## Hanatsu (Nov 9, 2010)

It's pretty normal with big dips and peaks in the bass area.

Here's a measurement of my old subs (2x 12" in sealed enclosures). No EQ or smoothing.


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## Oliver (Jun 25, 2007)

Any help here - http://www.diymobileaudio.com/forum...44399-rta-walkthrough-usage-thread-video.html



> Erin has multiple videos on youtube, 21 of em, I think at this time.
> 
> I've enjoyed several.
> 
> ...


REW RTA for car audio - YouTube

G'Luck


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## mooch91 (Apr 6, 2008)

Something still just ain't right. I listened for a while over the past couple of days, but there is still something "lacking". I've got great sub-bass, but things are not balanced in the midbass region.

I turned off my sub at one point today just to have a listen and it sounds so lacking. I've never thought my 6.5s in the doors have had the output I would have expected (the famed Pioneer midbass monsters), but I was never able to find a problem with the install. Doors are heavily deadened and sealed (and I saw little difference in output when I completed this).

Tonight I'm going to use the RTA to measure the relative contribution of the front speakers to the sub. I have a feeling that the sub is dominating the frequency response way up and that it would probably sound better if I could get more out of the fronts.


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## james2266 (Sep 24, 2009)

mooch91 said:


> Something still just ain't right. I listened for a while over the past couple of days, but there is still something "lacking". I've got great sub-bass, but things are not balanced in the midbass region.
> 
> I turned off my sub at one point today just to have a listen and it sounds so lacking. I've never thought my 6.5s in the doors have had the output I would have expected (the famed Pioneer midbass monsters), but I was never able to find a problem with the install. Doors are heavily deadened and sealed (and I saw little difference in output when I completed this).
> 
> Tonight I'm going to use the RTA to measure the relative contribution of the front speakers to the sub. I have a feeling that the sub is dominating the frequency response way up and that it would probably sound better if I could get more out of the fronts.


How much power do you have on your midbasses and how much on your sub? Maybe you need more on the midbass. That Pioneer midbass can take some power and from my listening it is a pretty damned good performer.


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## mooch91 (Apr 6, 2008)

james2266 said:


> How much power do you have on your midbasses and how much on your sub? Maybe you need more on the midbass. That Pioneer midbass can take some power and from my listening it is a pretty damned good performer.


I've got 150x2 on them and I'm running the set with the tweeter and passive crossover. The sub is getting 500x1.

Your comment is the same as everything I read about the set before I bought them. I've never been impressed. I started with deadened, but unsealed doors and thought that sealing them would solve the problem. It didn't. They just never seemed to have the low-end output I was expecting. I tried all combinations of polarity, even invested in an MS-8 for a short while to see if auto T/A would help, but never had them playing with any authority. I've tried every suggestion I was given to see if I could get them to deliver some more low end output.

I've just always chalked it up to me being a bass-head, or maybe something about the listening environment that wasn't working for me...


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## james2266 (Sep 24, 2009)

mooch91 said:


> I've got 150x2 on them and I'm running the set with the tweeter and passive crossover. The sub is getting 500x1.
> 
> Your comment is the same as everything I read about the set before I bought them. I've never been impressed. I started with deadened, but unsealed doors and thought that sealing them would solve the problem. It didn't. They just never seemed to have the low-end output I was expecting. I tried all combinations of polarity, even invested in an MS-8 for a short while to see if auto T/A would help, but never had them playing with any authority. I've tried every suggestion I was given to see if I could get them to deliver some more low end output.
> 
> I've just always chalked it up to me being a bass-head, or maybe something about the listening environment that wasn't working for me...


Well... they are still a 6 inch driver too. If you can; try this experiment. Pull the crossovers out of the game and run the midbass only actively. See if your output goes up immensely. Some comp sets have crossovers that chew up alot of power. What hi pass do you have on the set too? They should be able to handle 70 Hz easily and probably 60 Hz quite nicely too. I've only heard them on a display in my local dealer but I had them doing a comparo with the Audison Thesis Sax 6 right beside it. I actually thought the Pioneer had more impact. The Thesis tweeter blew the Pioneer away tho. Then again it should at its price point.

I just tried looking up specs on this but Pioneer's owner's manual is freakin' useless pretty much. It could be that this driver has a very low qts and does its best in a sealed enclosure? My best guess here as once again there are no TS parameters in Pioneer's useless owner's manual. Maybe this is why I don't like buying mainstream car audio speakers no matter their reputation


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## Hanatsu (Nov 9, 2010)

Have you checked relative phase between the sub/mid? You might have a cancellation around the crossover point. Change phase 0/180deg while running pink noise and watch the RTA.

Sent from my Samsung Galaxy 3 via Tapatalk.


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## mooch91 (Apr 6, 2008)

Hanatsu said:


> Have you checked relative phase between the sub/mid? You might have a cancellation around the crossover point. Change phase 0/180deg while running pink noise and watch the RTA.
> 
> Sent from my Samsung Galaxy 3 via Tapatalk.


There is definitely something going on with respect to cancellation in the 50 - 80 Hz range. But I only pick it up with my ears - I'm not seeing it on the RTA and consequently I've been ignoring it for a while. Maybe it's technique dependent (I'm continuously averaging and moving the mic in an approximate area around where my head would be) so that I'm not picking it up?

In the past I've done some longer-term testing with the sub at normal phase and reverse phase and neither sounds "great". Each always seemed to have its own compromises in the frequency response I heard.

Here's what I observed with my ears while playing tones today with the sub in "normal phase" (crossover now at 80 Hz):

With my head still, 80 Hz sounds lower than adjacent tones. I can almost make the 80 Hz tone "go away" by moving my head slightly around its normal position. When I move far forward towards the dash (or in the back seat), the 80 Hz tone is quite loud. 

Similar effect at 63 Hz. Although at this frequency, the change in level is less pronounced when I move my head slightly around my seating position, but when I move close to the dash or nearer the sub it gets much louder.

I'll have to experiment more at "reverse phase", but the interesting thing I noted with some quick listening is that although the 80 Hz situation gets better, the lower frequencies in the 50 - 80 Hz range sounded quite a bit worse.


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## mooch91 (Apr 6, 2008)

I think I might be confusing cancellation between drivers with modes, though...


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## james2266 (Sep 24, 2009)

Sounds like room mode is the issue. I have a similar problem with the sub. I have been told the only solutions are move the sub physical location or distribute the frequency amongst multiple locations. The first option is not an option for me so I am trying to get those frequencies produced from a diff. Location. I am trying a larger midbass that will hopefully produce the 60-70 Hz range where my sub is having the node problem. I am also going to try angling the sub box too as that might have a hearing too. That is about all I can do with the sub really. I should know if the new midbasses help later tonight as they will finally be installed tonight.


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## Hanatsu (Nov 9, 2010)

mooch91 said:


> There is definitely something going on with respect to cancellation in the 50 - 80 Hz range. But I only pick it up with my ears - I'm not seeing it on the RTA and consequently I've been ignoring it for a while. Maybe it's technique dependent (I'm continuously averaging and moving the mic in an approximate area around where my head would be) so that I'm not picking it up?
> 
> In the past I've done some longer-term testing with the sub at normal phase and reverse phase and neither sounds "great". Each always seemed to have its own compromises in the frequency response I heard.
> 
> ...


Sorry if I missed it but what's the lowpass frequency/slope on the sub and highpass freq/slope on mids?

Try download RoomEQ. Use sine sweeps and measure 5-6 times and average them. Sine sweeps will provide more data, you can observe the SPL vs Frequency as time decays via 'Decay' or 'Waterfall'. This way you can see if there's a modal issue. 

Try different slopes between sub/mids. Perhaps 12/12dB - 12/18dB - 12/24dB / octave or vice versa. Try 0/180deg phase on each setting. Check 'Overlays' (in RoomEQ) and determine which setting gives you the most SPL. 

Sent from my Samsung Galaxy 3 via Tapatalk.


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## mooch91 (Apr 6, 2008)

Hanatsu said:


> Sorry if I missed it but what's the lowpass frequency/slope on the sub and highpass freq/slope on mids?
> 
> Try download RoomEQ. Use sine sweeps and measure 5-6 times and average them. Sine sweeps will provide more data, you can observe the SPL vs Frequency as time decays via 'Decay' or 'Waterfall'. This way you can see if there's a modal issue.
> 
> ...


Sub and mids are currently at 80/24. I've had them all across the range, overlapped, and underlapped at times. Never seemed to get it right.

I will try some sweeps in REW. This is a function I have not yet used, so I will need some help interpreting results. I had hoped everything could be seen/solved with simple RTA, but I guess not.

I have a real hard time determining what "sounds" better between adjustments. There's always something that seems a little better, and always something that seems a little worse. Never "just right" with anything I've tried. Maybe I'm trying to make it too scientific, but I was hoping the RTA (and REW) would give me a more analytical way to determine when I've got it right.


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## Hanatsu (Nov 9, 2010)

Post the results and we'll interpret them for you 

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## mooch91 (Apr 6, 2008)

I was all ready to go with some impulse measurements with my system when I hit a snag.

Seems my sub amp is not responding to the line level output from REW and my Mobile Pre pre-amp. And I can't figure out why. My signal passes first in to the sub amp and is then sent out to my amp for the front speakers (just to simplify use of the crossovers). Front speakers are playing signal from the Mobile Pre just fine.

It's not REW or the Mobile Pre. I've hooked them up to a home stereo and they output fine across the range.

It's not the cable I'm using. I've connected an iPod to it and the sub amp and it's working fine.

The amp just won't play. Hook the head unit back up and it's fine.

I'm starting to really wonder if I've got some serious technical issue with my sub amp at this point that's complicating things...


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## mooch91 (Apr 6, 2008)

mooch91 said:


> I was all ready to go with some impulse measurements with my system when I hit a snag.
> 
> Seems my sub amp is not responding to the line level output from REW and my Mobile Pre pre-amp. And I can't figure out why. My signal passes first in to the sub amp and is then sent out to my amp for the front speakers (just to simplify use of the crossovers). Front speakers are playing signal from the Mobile Pre just fine.
> 
> ...


Got it, sort of...

The JL amp sums stereo channels to generate its output. REW must be generating its sweeps out of phase to each of the channels and they are summing to 0.

Remove either the L or R input to the amp and it works again.

But how to duplicate what I'm sending it from the head unit? The head unit is always delivering a stereo signal.


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## Hanatsu (Nov 9, 2010)

mooch91 said:


> Got it, sort of...
> 
> The JL amp sums stereo channels to generate its output. REW must be generating its sweeps out of phase to each of the channels and they are summing to 0.
> 
> ...


Not sure I understand the issue, the REW output should be in mono. Otherwise just mute the left or right channel from the soundcards output. You don't both outputs to measure


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## mooch91 (Apr 6, 2008)

mooch91 said:


> Got it, sort of...
> 
> The JL amp sums stereo channels to generate its output. REW must be generating its sweeps out of phase to each of the channels and they are summing to 0.
> 
> ...


Really got it. Just take one channel, split it, and go. Done. Mono in for the impulse measurements.


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## Hanatsu (Nov 9, 2010)

mooch91 said:


> Really got it. Just take one channel, split it, and go. Done. Mono in for the impulse measurements.


Indeed 

Bed time for me now, past midnight here. I'll follow up tomorrow.

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## mooch91 (Apr 6, 2008)

OK, bear with me. Impulse measurements are brand new for me. I've become quite expert at RTA, but this is new.

Here are three SPL plots of sweeps (blue - sub, yellow - fronts, red - combined). Crossover is at 60/24 on both and sub is at reverse phase. EQ is minimal (took at little away at 100 and 125 to keep the fronts relatively flat):









And here is the waterfall plot of the combined response. At the moment it's pretty meaningless to me, I'm hoping you guys can help me understand:


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## mooch91 (Apr 6, 2008)

I tried also doing some measurements of "normal" phase vs. "reverse" phase on the sub. Yellow is normal, red is reverse (combined response of sub + fronts shown). A little bit of difference between 60 and 150. Reverse was the "less humpy" response, so that's why I left it there:









And finally, a stereo RTA of the outcome for this evening:









It's definitely much lighter in the bass department than what I've been listening to.

Still perplexed by those 28 and 38 Hz peaks and those 24 and 34 Hz valleys.


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## mooch91 (Apr 6, 2008)

For kicks I toyed with some filters in REW to see how to flatten out the sub (combined response shown):









Unfortunately I don't have that kind of processing power. Maybe an investment I need to make...


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## Hanatsu (Nov 9, 2010)

The small dip at ~80Hz is a cancellation between mid and sub. The yellow plot is correct, keep it in 'normal' mode. You might be able to tweak the phase further with T/A. 

You got a lot going on around those two peaks. The waterfall plot shows you SPL (y-axis) vs Frequency (x-axis) vs Time (z-axis). It will show you SPL decay in time. As you can see, some of the sound pressure remains even after 500ms. You can't do much about it other than moving the sub physically perhaps. EQ will not fix the issue but it will help by bringing down those frequencies in amplitude. You would require a P-EQ to 'fix' those two peaks. Below 50Hz the sub plays perhaps 7-10dB too loud. You could boost 70-80Hz and lower gain on the sub amp to flatten out the response a little. 

Bass frequencies should be around ~10dB louder than ~200Hz+ for it to sound somewhat balanced.

Btw, you did average the plots you made? Can't average waterfalls but you can check them at multiple locations to see how decay pattern changes.

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## Hanatsu (Nov 9, 2010)

One thing you can try =

Lower the sub gain till it's 10-12dB lower. Then cross it 63Hz/24dB instead and the midbass xovers as they are right now.

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## mooch91 (Apr 6, 2008)

Hanatsu said:


> One thing you can try =
> 
> Lower the sub gain till it's 10-12dB lower. Then cross it 63Hz/24dB instead and the midbass xovers as they are right now.
> 
> Sent from my Samsung Galaxy 3 via Tapatalk.


Thanks Hanatsu.

Believe it or not, all speakers _are_ now crossed at 60/24. That extended response you see on the sub is actually what started this whole thread. I'll try to get some impulse measurements of the sub without any crossover, but if you take a look back at some of the RTA measurements (earliest posts), you'll see that the sub actually _rises_ considerably from 80 Hz on up (with no crossover). When I cross it over, that 80-100 Hz rise becomes a shelf that seems to be messing the overall response up. Probably why I'm liking reverse phase as opposed to normal - there's a little cancellation at that point that, at least visually, helps to flatten things out.


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## Hanatsu (Nov 9, 2010)

I gotta admit, your sub's FR looks weird. Never seen such a rise at 100Hz from a sub. What type of enclosure do you use btw?


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## Hanatsu (Nov 9, 2010)

Look at the "Decay" tab instead of "Waterfall". It's easier to see what's happening there imo. Here's a picture of my old 12" subs in small sealed enclosures. Draw a few lines, the green lines show my two major problem frequencies and the yellow line is how the sub measured outside the car (approximately). 

Each color in the decay plot shows SPL vs Frequency at a specific time shown at the bottom of the screen.


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## mooch91 (Apr 6, 2008)

Hanatsu said:


> I gotta admit, your sub's FR looks weird. Never seen such a rise at 100Hz from a sub. What type of enclosure do you use btw?


Simple sealed enclosure, at 0.8 cu ft (JL spec). 3/4" MDF coated with Line-X bedliner. Recently added some polyfill to it (no real change to measured or perceived output).

It was my first enclosure build, but I think I got it pretty tight. Screwed and glued. Sealed all of the inside joints with silicone. No air leaks past the driver itself.

I've checked my volume calcs at least three times as well (posted them in my build log).

I wish I could understand why its frequency response is all over the place. I don't know if an impulse response will reveal anything different from the continuously averaged result I posted previously, but I will give it a try. And I'll grab it with no smoothing too, which may be skewing its appearance.

Thanks.


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## Hanatsu (Nov 9, 2010)

cajunner said:


> seems like when you said "I move my head forward and the bass is more better" that was your sign.
> 
> it's not a good thing, but it's a good sign that you're having to drive in a null area in the car, the listening position is in a drop-out zone for bass that you need, bass you want...
> 
> ...


Agreed ^^


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## mooch91 (Apr 6, 2008)

Thanks to all you guys for your continued support with this. I'm going to keep trying...

Just a little off topic rant for a sec:

I know car audio is difficult, the environment is always working against us.

I am still amazed, though, at how difficult it can actually be. 

I've got a modest home setup, 675W 5.1 home theater receiver (270W when driven in stereo/music mode). Simple 10" two-way vintage Advent speakers. And with minimal setup (literally unbox, run Audyssey, and adjust bass and treble) and I get impact and dynamics that will take my breath away. Imaging and stage may not be perfect (my passion is more with tonality), but I smile no matter what I play on this system. I never want to make an adjustment.

I've experienced others' aftermarket car systems done on the cheap - simple components up front, 10" sub, 300W of power, and they bring the same kind of reaction. Beautiful dynamics, realistic lively bass. Again, maybe their soundstage isn't defined, but the tonality seems so right with so little effort invested.

Heck, I've heard some stock car systems that sound better than mine. And I'm not talking high end, either.

I've got 800W of power. I've deadened, sealed. I spent weeks wiring with no interior in the truck. I must have multiple thousands of dollars invested, not to mention over 4 years of tuning. I've run two different sets of components, two different subs. I've tried processors and EQs. And I can't seem to get away from the same issues and lifeless sound. I made some compromises in my install - passive components, shallow sub - but I expected much more from everything I tried to do "right".

Is the car environment really that bad? And those that get it right the first time, with a very simple system - did they just get lucky?

Sorry, rant over... now back on topic.


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## Hanatsu (Nov 9, 2010)

Yeah... that's how car audio is...

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## sqnut (Dec 24, 2009)

mooch91 said:


> Thanks to all you guys for your continued support with this. I'm going to keep trying...
> 
> Just a little off topic rant for a sec:
> 
> ...


Can you post an overall FR curve 20-20k, all drivers running? If you can get the overall FR in the ball park and get the drivers in phase, you certainly should not be lacking for wow factor.


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## mooch91 (Apr 6, 2008)

I just sprung for some processing power, picked up an RF 3sixty.3. Installed it today and spent a couple of hours tuning and things are so far so good. I think that the T/A helped, even with my passive system.

I've also created two tuning presets: one accomplished with mono pink noise, the other with stereo (I've been tuning entirely with stereo to date). Biggest difference is in the 500-800 Hz range. I'm actually liking the mono-tuned sound a little bit better.

I'm going to give it a listen and a little more tuning tomorrow. I'll let you all know how it turns out. And I'll get some final frequency response curves posted too.


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## Hanatsu (Nov 9, 2010)

Measure left and right side separately. It's important that both sides have equal amplitude.

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## sqnut (Dec 24, 2009)

^^ measure L/R, correct for L/R and then set the overall system curve. 

To OP: Ideally if you're setting L/R response it should be done one set of drivers at a time i.e. L/R for each woofer, then for the mids and so on. It may seem complicated but just hang in there for a bit . Something tells me the next set of curves you post won't be your last.


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## mooch91 (Apr 6, 2008)

sqnut said:


> ^^ measure L/R, correct for L/R and then set the overall system curve.
> 
> To OP: Ideally if you're setting L/R response it should be done one set of drivers at a time i.e. L/R for each woofer, then for the mids and so on. It may seem complicated but just hang in there for a bit . Something tells me the next set of curves you post won't be your last.


What's cool is that now I've got the capability to do so! Thanks.


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## sqnut (Dec 24, 2009)

Cool, will wait for the LR curves once you get some time to measure and post.

Edit : Maybe not now but down the line can you look at a different sub box? That shape just gives me the feeling that it would have a pesky response.....


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## mooch91 (Apr 6, 2008)

Here's where I ended up today. With the 3sixty.3, I now have the ability to make driver-by-driver EQ modifications. So one of the things I've started doing is removing the 80 - 100 Hz tail from the sub.

Here's where I ended up with things today, total frequency response, not matched left-right:









And here's a left-right plot for just the fronts. Blue = right, purple = left.









Please school me on the importance of having left-right amplitudes balanced. Is this strictly an imaging thing?


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## Hanatsu (Nov 9, 2010)

You want equal amplitude to get correct imaging. Especially important above 1kHz. The 100-700Hz needs immediate fixing, also 1200-2400Hz, 6-10kHz too. 

You have a fat cancellation 150-200Hz on the left side, a classic. You might wanna put a slight rolloff from 2,5-20kHz by 5-6dB. Bring down the 250-600Hz area on the left side by 10dB or so to begin with. Can help you more tomorrow, gotta sleep.


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## mooch91 (Apr 6, 2008)

Hanatsu said:


> You want equal amplitude to get correct imaging. Especially important above 1kHz. The 100-700Hz needs immediate fixing, also 1200-2400Hz, 6-10kHz too.
> 
> You have a fat cancellation 150-200Hz on the left side, a classic. You might wanna put a slight rolloff from 2,5-20kHz by 5-6dB. Bring down the 250-600Hz area on the left side by 10dB or so to begin with. Can help you more tomorrow, gotta sleep.


i.e., just flatten each side independently, from 60 on up, and consider a slight rolloff at 2.5kHz? Should be manageable. I'll probably start fresh with the EQ to make it easy.


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## sqnut (Dec 24, 2009)

As a first step just correct for L/R without worrying about the overall FR. Once you have corrected for L/R you will find that the overall FR curve looks different from what you have now. Once you have corrected for L/R take another reading for the overall FR and then start shaping the final curve.

A couple of points, first up some of the peaks are at frequencies that you wont have on your eq, eg 90hz. This can be sorted either using a PEQ or if say 80-100 is hotter from one side with a peak at 90hz, then cut 80 and 100 and see what that does at 90hz. Get it to within 2-3db for L/R in step one and then we will take it from there.

Also note how the summed response at a given frequency can be different from what the L & R side measure at that frequency. Eg at 1khz L=43 db, R=47 db but summed = 52db. This is caused by summation and cancellations from reflections. 

When you are correcting for L/R and you need to correct one side by say 4db, cut both sides while correcting. I.E. instead of setting the frequency 0/-4, you can try setting it at say -2/-6. It just sounds more balanced this way.


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## Hanatsu (Nov 9, 2010)

Try this. On the left side; 

250Hz Q4 -6dB
500Hz Q3 -5dB
800Hz Q6 -3dB
2000Hz Q6 -4dB
4000Hz Q3 -3dB
8000Hz Q1 -3dB

Right side;

160Hz Q3 -5dB
250Hz Q2 +3dB
1600Hz Q3 -3dB
3000Hz Q5 -3dB

Enter those and measure/average again. 

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## sqnut (Dec 24, 2009)

I would also add a -4 cut at 80hz L&R Q3.

Edit : Just went through the 360.3 manual and it lets you input the frequencies you want to or go with the default 1/3 octave. Thats great cause it lets you select specific problem frequencies. So now you can cut the peak on the left @ 6.5khz on a narrow curve etc.


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## mooch91 (Apr 6, 2008)

Thanks for hanging in there with me guys. I have a couple of questions on approach, if you don't mind. I'm thinking the answer to this might be "it doesn't really matter, you'll end up in the same place", but I want to confirm.

You've all suggested the following order of operations:
1. EQ flat. Correct L and R to each other (i.e., L and R match, regardless of curve shape).
2. Double check to confirm that L and R are near identical, measured independently.
3. Measure L+R together and shape to final curve, adjusting for summation and cancellation as they occur.

But how about the following, doesn't it get to the same place?
1. EQ flat. Correct L to have a flat response across the range.
2. Correct R to have a flat response across the range (and at the same level as L).
3. Double check to confirm that L and R are near identical, measured independently.
4. Measure L+R together and shape to final curve, adjusting for summation and cancellation as they occur.

Reason I am asking about the second method is because it was very easy for me to take measurements with EQ flat and have REW suggest 6-10 filters to flatten out each channel at 1/3 octave (I matched a flat curve with a 60/24 roll off). The filters become plug-and-play. If I were to just match channels, REW will give me an overall filter for both channels and it requires me to think more about which channel I'm cutting or boosting and by how much, so as to not bias the EQ to one side or the other.

I spent about 20 minutes programming the filters in on my lunch break. I'm anxious to measure the output when I get home.


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## mooch91 (Apr 6, 2008)

sqnut said:


> Just went through the 360.3 manual and it lets you input the frequencies you want to or go with the default 1/3 octave. Thats great cause it lets you select specific problem frequencies. So now you can cut the peak on the left @ 6.5khz on a narrow curve etc.


Yes, the 3sixty.3 lets you choose any frequency you want. REW generally recommends frequencies near the 1/3 octave defaults so there isn't much overlap that results from a single EQ analysis. Only drawback I can see with using non-1/3-octave frequencies is if you rely heavily on REW to suggest your filters (and I have been right now); as you do successive rounds of EQ, REW will continue to suggest additional frequency values and you'll soon run out and incur a lot of overlap.


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## mooch91 (Apr 6, 2008)

mooch91 said:


> I spent about 20 minutes programming the filters in on my lunch break. I'm anxious to measure the output when I get home.


Image placement was _stellar_ upon a quick listen, by the way.


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## Hanatsu (Nov 9, 2010)

mooch91 said:


> Thanks for hanging in there with me guys. I have a couple of questions on approach, if you don't mind. I'm thinking the answer to this might be "it doesn't really matter, you'll end up in the same place", but I want to confirm.
> 
> You've all suggested the following order of operations:
> 1. EQ flat. Correct L and R to each other (i.e., L and R match, regardless of curve shape).
> ...


http://diymobileaudio.com/forum/showthread.php?t=144455

Check that out. Made a thread regarding this.

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## mooch91 (Apr 6, 2008)

Jumping ahead a bit...

When I get to EQ'ing that transition region between the mids and the sub (63-200 Hz) - how much of the rise in output should be coming from my mids, and how much from the sub? Should my mids stay flat, letting the sub pick up the transition? Or should I look for equal contribution in this region?

As you can see - I have a good deal of peakiness from the front mids in this area.


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## Hanatsu (Nov 9, 2010)

mooch91 said:


> Jumping ahead a bit...
> 
> When I get to EQ'ing that transition region between the mids and the sub (63-200 Hz) - how much of the rise in output should be coming from my mids, and how much from the sub? Should my mids stay flat, letting the sub pick up the transition? Or should I look for equal contribution in this region?
> 
> As you can see - I have a good deal of peakiness from the front mids in this area.


Eh... not sure I follow. Mids and sub should be equal in amplitude at the transition point (with the applied crossovers). Lets say;

Sub; 20-80Hz (10dB+)

Mids; 80Hz (10dB), rolloff to 250Hz (0dB) - flat to 2500Hz

Rolloff 6-7dB from 2500Hz to 20kHz.


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## sqnut (Dec 24, 2009)

mooch91 said:


> Jumping ahead a bit...
> 
> When I get to EQ'ing that transition region between the mids and the sub (63-200 Hz) - how much of the rise in output should be coming from my mids, and how much from the sub? Should my mids stay flat, letting the sub pick up the transition? Or should I look for equal contribution in this region?
> 
> As you can see - I have a good deal of peakiness from the front mids in this area.


I look at an octave above and below the xover point as the transition zone. I have my sub and mid crossed at 50 hz. At the xover point, the sub is about +10 db louder than the mids, they are about even at 80 hz and above 80HZ the mids get progressively stronger. You can shape this transition using your slopes and the eq. You can play around in this zone and see what transition point sounds best. I normally follow this logic while setting the driver response in this range.

In your case, yes you have a big hump from ~70-160 on your mids. In your overall response curve, you want to flatten the peak from 70-90. 30-60hz is about 70hz and 100 is about 2-3db lower. That roll off needs to be steeper. Try and set it so that 100 is about 6-7db lower and 160hz idown 10 db from the 30-60 zone. 

So I would cut both mids by ~ 4db on a q of 2-3. I want the cut to affect 60 to 125 hz. 

Oh and BTW I can relate to tuning lunch breaks totally. Used to do that a lot 4-5 years ago. I guess the bug has bitten you nice and proper. 

To answer your original question, in my example if 50 were the xover *and* response transition point, then an octave below would be 95% about sub response and an octave above would be 95% mid, with a smooth transition between the drivers in this zone.


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## mooch91 (Apr 6, 2008)

OK, I'm going to have to process your feedback a little more before I do anything in the 60-200 Hz region. I think I've got 200+ pretty good after a quick tuning session last night (after my son went to sleep!). I also think I can shape the sub just about any way I want it. 

I guess what I'm trying to decide is what to do with the transition zone - should I be pulling down the overall response peak by cutting from both mids, one more than the other, or the sub? Or should I be moving the crossover since the individual driver peaks here are so odd (and they roll off on the low end so steeply)?

Maybe the discussion needs some updated curves in order to be answered.

Be back in touch after I've had my morning coffee...


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## sqnut (Dec 24, 2009)

*Big Picture :* Think of a transition zone above and below xover points. You want the response to transfer from one set of drivers to the next in this range. You want this transition to be smooth. Much like the baton transfer in a relay race. You can use slopes and eq to control the response pattern of the drivers in this zone.

So if based on desired transition at a particular frequency its 70% mid and 30% sub then for a notional 4 db cut, I would cut 3 db on the mid and 1 db on the sub.....

*Within that Big Picture:* You want a roll from ~60 to 200 hz where in 60 hz is 10db louder than 200hz. Based on your overall curve you should cut as suggested @ 80hz.

It would be a good idea to update the current response curves.


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## Hanatsu (Nov 9, 2010)

Send me the entire project file (as a zip file or something) in REW via email, I can give you a better answer how setup EQ and crossovers 

I want 6 measurements for each driver at listening position (measure around where the head is 4-6" apart). I can give you a nice guestimate on optimal settings then.

Otherwise, go with Sqnut's suggestion.

Mail; [email protected]



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## sqnut (Dec 24, 2009)

He's hungry and you're offering to feed him fish. I'm trying to teach him how to fish. What we are saying is not very different. The context may be slightly different though.


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## Hanatsu (Nov 9, 2010)

lol xD

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## mooch91 (Apr 6, 2008)

You guys have both been very helpful and I much appreciate your support. You're helping me understand, as opposed to just doing, which is very important to me.

I'll be back at it tomorrow. I had a lengthy tuning session tonight where I think I finally got L-R balance, got a decent final response curve across the range, and got pretty good integration. I'll listen and share tomorrow.

I'm letting REW pick my filters, so after going through 3 iterations, I have quite a few. Filters on filters in some cases. I kept my boosts relatively small, so I hope that I didn't end up with too much EQ action.

Thanks!


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## mojozoom (Feb 11, 2012)

mooch, you can let REW tell you what the transition should look like for your sub roll off and your mid roll off at the bottom end.

When you go to the EQ screen for your mid for example, go to Target Settings, and pick Bass Limited for the speaker type, and set the crossover slope and cutoff frequency. Then REW will modify your housecurve to include the effect of the crossover. 

You are using a housecurve, correct?


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## Justin Zazzi (May 28, 2012)

I love seeing threads like this. I'm tempted to jump in and "help" too, but I fear it would be too many cooks in the kitchen. Keep up the great discussion!

-J


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## ErinH (Feb 14, 2007)

Jazzi said:


> I love seeing threads like this. I'm tempted to jump in and "help" too, but I fear it would be too many cooks in the kitchen. Keep up the great discussion!
> 
> -J


ditto. at some point you feel like you're contending with so many others' input/opinions so much that it's not even helping. lol.


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## mooch91 (Apr 6, 2008)

mojozoom said:


> mooch, you can let REW tell you what the transition should look like for your sub roll off and your mid roll off at the bottom end.
> 
> When you go to the EQ screen for your mid for example, go to Target Settings, and pick Bass Limited for the speaker type, and set the crossover slope and cutoff frequency. Then REW will modify your housecurve to include the effect of the crossover.
> 
> You are using a housecurve, correct?


Yes - found this and have been using it. Set my house curve to a 60/24 crossover like I'm using. Interesting thing is that my mids are rolling off very sharply before 60/24... But I tried to get it to match up some.


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## mooch91 (Apr 6, 2008)

Left (purple) and right (blue) curves as they stand today:









Combined response of the left and right. Interesting thing is that 200 Hz dip that I've not seen before. That developed when I balanced the levels of left and right across the range. It's not as pronounced at 1/3-octave smoothing, but it's still there.









And the final frequency response with sub (I actually shaved a couple of dB off from the left driver fairly wide around 100 Hz, so the true final curve - which I didn't measure - is a little smoother in this region):


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## mooch91 (Apr 6, 2008)

And the target I've been using:


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## mooch91 (Apr 6, 2008)

I'm thinking the cancellation at 200 Hz is due to some over-adjustment to make the mids' output look about the "same" in this region. I actually had to force some filters that REW wasn't making on its own to shape this region, primarily adding quite a bit to the left mid between 125 and 315 (or so).

I know having equal output is important for an imaging perspective, but is it critical at 200 and below?

My thought for the next round of tuning would be to let REW recommend filters for 200 on up, balance L and R with each other, and then shape the overall response (with the starting point for the mids at 200 on down at their un-EQ'ed output).

Sound was decent this morning on my drive to work. It did sound a little "fat" in the midbass (or the higher end was a bit muted) and elements of the image were moving quite a bit (and seemed more biased to the right side).


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## sqnut (Dec 24, 2009)

60 hz is probably at or close to the drivers Fs below this the drivers response will roll off sharply, plus you have it on a 4th order slope. Don't worry about the 6.5's response below 60. With a xover at 60hz the transition is probably ~80-90ish. So the 60-100 range is important when you are looking at response of drivers. Don't boost the MB below 60 to try and match the sub.


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## Hanatsu (Nov 9, 2010)

L/R plots looks great now. The dip at 200Hz looks strange, did it happen after EQing the drivers?

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## Hanatsu (Nov 9, 2010)

Next step, have you measured time delay? The image shouldn't shift with that good L/R frequency response. 

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## mooch91 (Apr 6, 2008)

Hanatsu said:


> L/R plots looks great now. The dip at 200Hz looks strange, did it happen after EQing the drivers?
> 
> Sent from my Samsung Galaxy 3 via Tapatalk.


Yes. That's why I was thinking of not eq'ing the drivers individually to match each other near the 200 point but instead eq them for overall response.


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## mooch91 (Apr 6, 2008)

L and R are at about the same level when measured individually but cancel completely when measured together. They seem to sum better when not eq'ed to match in this region.


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## ErinH (Feb 14, 2007)

mooch91 said:


> They seem to sum better when not eq'ed to match in this region.


I've noticed this as well. It's because you're in the pressure region trying to fix nulls via EQ is a bad idea here. This is why I typically tune by ear below 300hz and use the mic to help me spot specific ringing issues and smooth the response I obtained by ear.


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## Oliver (Jun 25, 2007)

mooch91 said:


> Sound was decent this morning on my drive to work. It did sound a little* "fat" in the midbass* (or the higher end was a bit muted) and elements of the image were moving quite a bit (and seemed more biased to the right side).


Your mids are not producing "Faux bass" , or in other words mounted in doors ?


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## mooch91 (Apr 6, 2008)

Oliver said:


> Your mids are not producing "Faux bass" , or in other words mounted in doors ?


They are mounted in doors...


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## sqnut (Dec 24, 2009)

mooch91 said:


> I'm thinking the cancellation at 200 Hz is due to some over-adjustment to make the mids' output look about the "same" in this region. I actually had to force some filters that REW wasn't making on its own to shape this region, primarily adding quite a bit to the left mid between 125 and 315 (or so).
> 
> I know having equal output is important for an imaging perspective, but is it critical at 200 and below?
> 
> ...


At what resolution are these curves? How have you set 200hz for the left side on the eq?

Even after you've got it sounding accurate, the system FR is always going to be a jagged line even at 1/3 oct. Is there's a blockage about 16-18" from the left mid? it could be a reading error. If you have a sound meter app on your phone calibrate the mic and take a reading L&R playing at 160 and 200 hz. Is 200hz 20db down from 160? That is what you combined curve is showing. You can also cross check by doing this for l?R side. 

it's best to match L/R even below 200, but below 200 the ears are more sensitive to phase difference rather than amplitude.

Edit : Fat in the mid bass could be due to the hump from 80-100


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## Hanatsu (Nov 9, 2010)

bikinpunk said:


> I've noticed this as well. It's because you're in the pressure region trying to fix nulls via EQ is a bad idea here. This is why I typically tune by ear below 300hz and use the mic to help me spot specific ringing issues and smooth the response I obtained by ear.


Good idea ^^

Haven't thought about it but when you mention it, I always fiddle with the EQ in that region when I'm fine-adjusting by ear after the measurement.

To op; try running a signal generator (there's one in RoomEQ) through the input AUX (if you got an AUX, that is) or burn a cd with test tones and check if all tones sound centered. This requires that T/A is correct but it's a good method to fine adjusting FR by ear after measurements. I always end up correcting 1dB or so up/down.

Sent from my Samsung Galaxy 3 via Tapatalk.


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## Hanatsu (Nov 9, 2010)

Hanatsu said:


> Good idea ^^
> 
> Haven't thought about it but when you mention it, I always fiddle with the EQ in that region when I'm fine-adjusting by ear after the measurement.
> 
> ...


Double post....

Sent from my Samsung Galaxy 3 via Tapatalk.


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## sqnut (Dec 24, 2009)

Try cutting both sides at 80 and 200 does it make the lower end tighter and less heavy? If so I would just ignore the divot at 200.


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## mooch91 (Apr 6, 2008)

sqnut said:


> At what resolution are these curves? How have you set 200hz for the left side on the eq?
> 
> Even after you've got it sounding accurate, the system FR is always going to be a jagged line even at 1/3 oct. Is there's a blockage about 16-18" from the left mid? it could be a reading error. If you have a sound meter app on your phone calibrate the mic and take a reading L&R playing at 160 and 200 hz. Is 200hz 20db down from 160? That is what you combined curve is showing. You can also cross check by doing this for l?R side.


These are full resolution (presumably 1/48 octave). Left side has some big boosts in the 160 - 250 region and the right has some big cuts. The un-EQ'ed response on the left side had a big valley there and the right side was a bit peaky. I believe the un-EQ'ed plots can be found somewhere earlier in this post (I'm losing track), if not I will re-post them. 

The blockage 16-18" from the left mid could be the steering column and steering wheel, I guess? But why would this not show up on the plot of L alone, and cancel when L and R are combined?


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## mooch91 (Apr 6, 2008)

sqnut said:


> Fat in the mid bass could be due to the hump from 80-100


I did make some adjustments to that region that aren't reflected in the latest plots I posted. That hump should be reduced in the latest tune.


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## mooch91 (Apr 6, 2008)

Hanatsu said:


> To op; try running a signal generator (there's one in RoomEQ) through the input AUX (if you got an AUX, that is) or burn a cd with test tones and check if all tones sound centered. This requires that T/A is correct but it's a good method to fine adjusting FR by ear after measurements.


Good idea, I was saving this for the fine tuning once I was 95% happy with where I ended up. Getting closer but not quite there yet...


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## sqnut (Dec 24, 2009)

mooch91 said:


> These are full resolution (presumably 1/48 octave). Left side has some big boosts in the 160 - 250 region and the right has some big cuts. The un-EQ'ed response on the left side had a big valley there and the right side was a bit peaky. I believe the un-EQ'ed plots can be found somewhere earlier in this post (I'm losing track), if not I will re-post them.
> 
> The blockage 16-18" from the left mid could be the steering column and steering wheel, I guess? But why would this not show up on the plot of L alone, and cancel when L and R are combined?


1/48 oct is way to high for a car. Just so that you don't get lost in this maze it might be a good idea to use a baseline of 1/3 oct and then from time to time drop down to 1/6 to see if anything needs correction. 

Be careful with the 160-200 range in the combined response. 160hz is tricky. A touch less can make the sound thin and a touch more can make it fat and bloated. If you have balanced for L/R then make small and equal ( for left/right) cuts at 160 and 200. Does the fat / heavy sound become tighter? 


Even with the mids mounted high in the doors and firing directly into the steering column you should not get a null of 12db. If the mids are down low in the doors then obviously the steering is not an issue.

Can you post current curves at 1/3 oct?


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## Hanatsu (Nov 9, 2010)

120-250Hz is a range where the car's acoustics usually create issues. It can be hard to get right as sqnut said. Experiment with it.

1/6 is usually enough resolution. The higher resolutions are good as reference. Very narrow dips are often less audible than wide ones and the lower resolution kinda smooths them out, it can therefore seem like you have wider dip than you actually got... So double-check against the higher resolution plot.


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## mooch91 (Apr 6, 2008)

I'll be posting some latest tunes tonight...

I found today that if I try to match the 100-300 region left to right (i.e., make the left and right look similar), I get that huge cancellation at 200 Hz.

If I leave left and right unmatched, but just adjust the combined output to match the target curve, the cancellation never appears.


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## Hanatsu (Nov 9, 2010)

mooch91 said:


> I'll be posting some latest tunes tonight...
> 
> I found today that if I try to match the 100-300 region left to right (i.e., make the left and right look similar), I get that huge cancellation at 200 Hz.
> 
> If I leave left and right unmatched, but just adjust the combined output to match the target curve, the cancellation never appears.


Interesting. I'll take a look at the plots tomorrow


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## mooch91 (Apr 6, 2008)

OK, I'm back to 1/3-octave plots (all plots are continuously averaged for about 60 seconds, moving the mic in a figure 8 around the driver's head location, by the way)...

In case I didn't post it earlier, here is my "starting point" for the L and R sides. These are completely un-EQ'ed (crossed at 60/24). Black is L and blue is R:









Here is what they look like with EQ, trying to match across the whole range as you've suggested. Green is L, purple is R, and blue is combined. You can see the dip at 200 Hz has developed. This was starting from scratch today, same result as I posted the other day.









Full output of this tune, including sub (vs. my target curve):









Stay tuned for plots where I tuned for overall response below 300 Hz (and not a L - R match)...


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## masswork (Feb 23, 2009)

Dip that occurs when L and R plays together? Looks like a mis-time align to me.

Anyway, you need a better resolution for low frequency.
Look at the group delay plot, and avoid EQ ing areas where GD plot is peaking or dipping.


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## sqnut (Dec 24, 2009)

How does it sound?


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## mooch91 (Apr 6, 2008)

sqnut said:


> How does it sound?


Not so hot...


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## mooch91 (Apr 6, 2008)

masswork said:


> Dip that occurs when L and R plays together? Looks like a mis-time align to me.
> 
> Anyway, you need a better resolution for low frequency.
> Look at the group delay plot, and avoid EQ ing areas where GD plot is peaking or dipping.


masswork,
Can you elaborate? I've set T/A with the 3xity.3. Since I'm running passive, I T/A'ed off the mids. Distance to my right mid from my right ear is 65", distance to my left mid from my left ear is 45". I've added 20" of delay to the left front channel. Also added 20" of delay to the sub channel as it's about 45" from the center of my head.


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## masswork (Feb 23, 2009)

Passive?
The whole side passive or midr/tweeter only?

I see you have access to measurement and REW, can you send me the .mdat file for each driver/combo:
1. Left midbass
2. Right midbass
3. Left midrange
4. Right midrange
5. Sub

If you're using passive, can you disconnect the tweeter before measuring each driver?


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## mooch91 (Apr 6, 2008)

masswork said:


> Passive?
> The whole side passive or midr/tweeter only?
> 
> I see you have access to measurement and REW, can you send me the .mdat file for each driver/combo:
> ...


Two-way components, so mid = midbass = midrange (6.5). Passive xover between the mid and tweeter. Active between the sub and passive combo.


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## sqnut (Dec 24, 2009)

Why do you have a passive in the mix when you can keep it simple and run everything active via the 360.3?


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## mooch91 (Apr 6, 2008)

sqnut said:


> Why do you have a passive in the mix when you can keep it simple and run everything active via the 360.3?


Based on the way things are wired and set up for me, its not as easy as it seems.


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## sqnut (Dec 24, 2009)

Damn I was 90% done with a long post and I clicked to close the screen i/o of minimizing the damn thing.................this time I'm going to do it in word and then copy paste. At least word has auto save

Edit : Will do it tmrw morn my time. Been a long day.


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## Hanatsu (Nov 9, 2010)

sqnut said:


> Damn I was 90% done with a long post and I clicked to close the screen i/o of minimizing the damn thing.................this time I'm going to do it in word and then copy paste. At least word has auto save


Annoying...

Sent from my Samsung Galaxy 3 via Tapatalk.


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## mojozoom (Feb 11, 2012)

mooch,

The most important thing I've learned in the last year is that everything in the system hinges on the TA setting between your right mid and the sub. Getting this right can fix muddiness, distortion, and poor midbass problems and let your future tuning have the effect you want.

Can you do this for us, to illustrate something that's worked for me and should help you and facilitate some discussion:

Set the right mid TA to 0, same as the sub. Turn on only the sub and the right mid. In a passive the tweet an be on as it won't play into the results. Now run a sweep with REW, increase the mid delay by 6", sweep again, increase again, sweep again, etc, all the way up to about 9' of delay. No need to use the RTA or any averaging for this.

Now you should have what my daughter called a "rainbow". Limit the display to show just the range from 30 hz to 200 hz as thats all we care about. Now you can switch off the traces one by one until you find the one that gives you the best summation at the crossover frquency, but also minimizes crazy spikes or dips above or below it.

If you have a tie between two traces, you may want to look at the GD overlay for them and pick the one with the lower overall GD.

You may want to make rainbows with 24 db slope on the sub and 24 db on the mid, then 12 db slope on the sub and 24 db slope on the mid, etc. You may find one of those combos works better than others, but I dont expect youll want to try with 12 db slope on the mid as you're crossing them pretty low.

Once you figure out which of the 6" separated curves is closest, do it all again in fine increments (2" on the 3sixty.2) starting about 6" before the best pick from before and ending about 6" after. Then you pick the best from those and you're done. It should look something like this (I was using a 65 hz crossover):









Once that's figured out we can start to worry about setting the TA for the other side.

Let's see some rainbows!


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## sqnut (Dec 24, 2009)

mooch91 said:


> Not so hot...


Lol that's very descriptive . 

I'm just guessing here but, is the sound kind of thin and raspy? A touch of harshness to the vocals and maybe some sibilance. A boomy and heavy lower end, while on certain tracks at times it feels like there is no lower end, lack of dynamics etc. Feels like you're listening to a low bit rate compressed file. 

While you may or may not have the issues above, there is a reason I used some subjective terms. You've got to a point where the L/R balance is good and I'm assuming the TA is decently in the ball park. The next step is to shape the overall response curve that gives you the best tonality. Accurate sound with realism. Sound that you would get from a decent 2ch or a good pair of buds. 

The response curve that will give you that sound, will factor in your environment and install locations, the drivers capability and your ears sensitivity at different frequencies. The fun part is that you'll do this bit by ear. A couple of things to note, get a good reference base for the sound you want and get familiar with what cutting / boosting each frequency does to the overall sound. That will give you the ability to hear a problem and then make a correction. 

http://upload.wikimedia.org/wikipedia/commons/thumb/4/49/Lindos4.svg/669px-Lindos4.svg.png

I find the FM curves helpful in setting the overall curve. The curves are an estimated measure of the ears sensitivity at different frequencies. The sensitivity changes with frequency and loudness. It explains why you set your low end 10-12 db louder than say your mid bass region and why you're looking at a flatish response in the 200-1khz range. It also gives an indication of what could be wrong in your response curve. 

The ears sensitivity is highest in the `2-4khz range so this range needs to be lower than your base level of 200-1khz. Your overall curve needs to start rolling off around 1.6khz so that the 3-6khz range is about 3-4db lower. Also remember that sibilance is in the 6-8khz range, which is another reason to have that range lower. You can then raise the response curve by a few db's in the 10-12khz range and then your drivers and environment will roll things off above that in any case. 

Some Possible Issues : 

1. If you have a passive between the mid and tweet and are running the two as one channel and your mids and tweets are separated by more than 2-3 inches, then you have an issue. 

2. With PEQ's it may not be a great idea to stack filters at the same frequency on different q values. I'm not very technical and hope some one explains this a bit, but it just doesn't sound right.

Suggested settings:

1. Cut the Mids at 80 hz on a q of 2 by 4db.
2. Cut at 3khz on a Q of 1 by 4 db.
3. Cut at 6khz on a Q of 2 by 4 db

These are broad suggestions which you can fine tune. Does it sound different? slightly better?


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## Hanatsu (Nov 9, 2010)

Narrow band EQ (high Q) should only be used within the lowest 3-4 octaves (in the modal range). The response above this point will shift if you move your head just a little. Use lower Q values when EQing midrange/tweeters

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## mooch91 (Apr 6, 2008)

OK, I'm going to try to get some time in the truck to tune today (hopefully), so I have a couple of brief questions for you guys right now:

mojozoom - Rainbows and T/A before or after EQ? That is, should I complete this with everything flat, or should I be using my current "best case" tune?

sqnut - I will try your suggestions with my current tune and I will establish a fresh tune with a modified taregt curve that incorporates much of what you described in it. Sorry I was brief with my initial response to the "how's it sound" question - as you guessed there were just some things that weren't right and I was frustrated at the time. I've been using a target curve that's very flat all the way up and I agree that a harsh top end could be leaving me dissatisfied with the lower end transitions. I'm going to leverage a target curve with more high-end roll-off as you've described and a smoother transition at the low end.

Hanatsu - Thanks for that advice. I was probably not as conscious of where I was using high Q/low Q within the frequency spectrum. I'll use this rule of thumb going forward.

Stay tuned (no pun intended)... Weather is a little chilly here today which throws my frequency response off a little and makes for a challenging time tuning. Hopefully my batteries make it through another session, not sure how much more they can take!


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## Hanatsu (Nov 9, 2010)

Have a battery charger connected to the batteries when tuning if possible 

I too generally prefer a rolloff above 2,5kHz by 6-7dB to 20kHz.

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## mojozoom (Feb 11, 2012)

mooch,

After eq is the best as your eq impacts the shape of the phase curve. You could do a few iterations because the TA changes will impact the FR curve.


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## mooch91 (Apr 6, 2008)

mojozoom said:


> Then you pick the best from those and you're done. It should look something like this (I was using a 65 hz crossover):


In your example, which of the curves is "optimum"? I assume one of the red ones at the center of the cluster that is relatively flat across the range?


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## mooch91 (Apr 6, 2008)

Rainbow plots as suggested (sub to right mid), 6" increments:









I'm going to need some help interpreting.

The "smoothest" curve is the top one which is 0" delay between the two.


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## Hanatsu (Nov 9, 2010)

mooch91 said:


> Rainbow plots as suggested (sub to right mid), 6" increments:
> 
> 
> 
> ...


And that would be the best one


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## mojozoom (Feb 11, 2012)

I agree with you guys - the 0" curve looks like the best ballpark to target so far.

Now you need to run some at 1" or 2" intervals around that one to try to pin it down even closer.

It may be that the best alignment is below 0". To check that youll need to flip the polarity on the sib and run another set of 6" rainbow sweeps.


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## mooch91 (Apr 6, 2008)

mojozoom said:


> I agree with you guys - the 0" curve looks like the best ballpark to target so far.
> 
> Now you need to run some at 1" or 2" intervals around that one to try to pin it down even closer.
> 
> It may be that the best alignment is below 0". To check that youll need to flip the polarity on the sib and run another set of 6" rainbow sweeps.


I had the mid set at 0 and was delaying the sub at 6" intervals (since my mid is the furthest distance in my speaker set). Wouldn't "below 0" mean setting the sub to 0 and delaying the mid?


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## mojozoom (Feb 11, 2012)

I see now -

You probably want to run sweeps with 0-6" delay on the sub, then with the sub at 0" try delaying the mid from 0-6".

That should allow you to hone on on the best alignment. What's the lowest delay increment on the 3sixty.3? On the .2 it's 2" which is a little coarse.


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## sqnut (Dec 24, 2009)

Looks like the TA between the sub and the mids is good for now. Did you get a chance to play with the eq settings?


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## mooch91 (Apr 6, 2008)

sqnut said:


> Looks like the TA between the sub and the mids is good for now. Did you get a chance to play with the eq settings?


Yes I did...

To avoid stacking a bunch of PEQ filters, I did a complete re-EQ to a new target curve with more of a roll-off. Here is the product of L (light green), R (red), and combined vs. that curve. These are with 20" of delay between the left and right mids:










The T/A between the two is a heavy contributor to that dip at 200 and that dip at 500. With no T/A between the two drivers I have a similar curve without those dips but with a bigger dip at 300 Hz:










I could use some advice on setting the delay between R and L (assuming now I'm close on the delay between R and sub). I got curious and ran a bunch of RTAs (continuous averaging for at least 30 seconds with a figure-8 sweeping motion of the mic) and saw that these peaks and valleys shift all over the place depending on the T/A setting. I have a similar "rainbow plot" for 3" time delay added to the left driver from 0 - 42":










I don't even know where to start with that one, none of them is free of a major issue that EQ will likely not solve. Can anyone school me on how I can continue the T/A process?

Thanks!


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## masswork (Feb 23, 2009)

try looking at 1/24 or 1/48, you will see which side contributes the dip.
you need that resolution for bass region


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## Hanatsu (Nov 9, 2010)

This is to be expected.

You cannot deal with this the same way. T/A should be used to improve your staging not to modify the FR. The wavelengths above the schroeder frequency will vary as soon you move the mic just slightly. You can make such a 'rainbow' by not touching T/A and just move the mic around. Hence the need for averaging the FR plots at several points. 

Set T/A to center the stage. EQ to deal with the artifacts in the averaged FR.

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## mojozoom (Feb 11, 2012)

I agree with Hanatsu there. Don't try to TA for FR between the mids at this point, or probably ever. The phase curves will be so different between the two mids that you'll never get them to line up. 

This is why door mounted drivers aren't optimal. But we can still optimize what we have. The combined response has almost no value to us as we cant completely fix it anyway, so focus in on tuning on ear at a time. Tune the right side with the mic at your right ear, then the left with the mic at your left ear, then look at both graphs an apply eq changes to each in order to line them up with each other. Especially in the midrange.

To get proper imaging the impulse response of the mids needs to match. If you don't have loopback on your REW setup you can use HolmImpulse, but REW with loopback would be most accurate.

Once you check the impulse responses, delay the left side mid as required to get them to match. That gets you in the right ballpark. Then throw on an 800 hz band of pink noise and tweak the left side TA up or down a little until the image comes into focus.

BUT, I'd finish the fine tuning on TA for the sub to right mid first, as you could be off by a bit yet as you were using 6" increments.


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## james2266 (Sep 24, 2009)

mojozoom said:


> I agree with Hanatsu there. Don't try to TA for FR between the mids at this point, or probably ever. The phase curves will be so different between the two mids that you'll never get them to line up.
> 
> This is why door mounted drivers aren't optimal. But we can still optimize what we have. The combined response has almost no value to us as we cant completely fix it anyway, so focus in on tuning on ear at a time. Tune the right side with the mic at your right ear, then the left with the mic at your left ear, then look at both graphs an apply eq changes to each in order to line them up with each other. Especially in the midrange.
> 
> ...


I'm curious as to why you mention 800 Hz as a frequency to target for adjusting time alignment between midranges. Why this specific band of pink noise?


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## mojozoom (Feb 11, 2012)

I think my logic for using 800 hz started with the idea that since both intensity and time play into staging from 500-2000 hz, using a freq in the middle of that range (about 1200 hz) would make sense.

But, the top end of the male voice fundamental frq is about 800 hz, so I had to bring my selection down a bit as I feel like vocals are really my target for good imaging.

If you use an RTA to make sure each side has the same FR thru the 500-2000 hz band then I think you really only need to target one freq for testing TA to get it all to work well. If you aren't using an RTA you would want to listen to separate bands and balance levels at each band (there are other good posts on that methodology).


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## mojozoom (Feb 11, 2012)

One thing I should add though -

Every install is different, so if a given car has more reflection going on, or if your head is substantially smaller than mine, or whatever else, you may still not get the imaging you want by establishing a matching left/right FR in the 500-2000 hz range.

At that point the best path would be to go through each band of pink noise and adjust the L/R levels until you get a centered image for each, which will throw off your tonality slightly. If you move one side up and the other down by equal amounts overall it shouldn't be too big a deal.

So it looks to me like the best general progression to the process would be:
1) EQ each side independently until they match (especially in the 500-2000 hz range)
2) Run an impulse test and delay the left side accordingly to line up the responses
3) Fine tune the left delay setting based on 800 hz pink noise to center the image
4) Fine tune L/R freq levels based on pink noise bands from 500-2000 hz to center the image for each

Also keep in mind that if you FR goes wonky at 800 hz on one side for some reason, and can't be balanced exactly with the other side, then you should use a band that is balanced on both sides, maybe 1000 hz.

All of this would be with the sub off of course, and assuming you've already established the best alignment between the sub and the right side mid via rainbow plots.


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## Hanatsu (Nov 9, 2010)

Or a 800Hz sine tone


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## james2266 (Sep 24, 2009)

Hmm, that all makes sense actually. I have been trying to set time alignment as best I can with a solid center vocal for the longest time. It was usually a narrower voiced female voice like Diana Krall. I had only alright luck with that. I have just started to use band limited pink noise to center up various bands. I haven't had the chance to really set ta with these bands however. I will have to try that out whenever I actually get some time and it isn't too freakin' cold outside. I actually have a bunch of things I would like to get doing and many of them are car audio related.


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## mooch91 (Apr 6, 2008)

Well, spent much of the last two days tuning (much to the disappointment of my wife and son) and I just don't think it's getting any better...

I got the curve as close as I could to the target I posted in #136 above. Left and right are nearly identical across the range (still have the sharp dip that develops at 200 Hz when combined). T/A between the right mid and sub is 0 (I ran up to 6" delay around 0, at 1" intervals and all the curves practically landed on each other, so I figured 0 was not far off). I've got 20" delay on the left side which seems to position the image pretty effectively.

I ran for a while with sub off this morning and bass sounds pretty awful, not realistic in the least. A pair of 6" bookshelf speakers at 80x2 in my garage frankly sound better...

Adding the sub helped (cover up?) but it's still overpowering.

Vocals sounded a little flat and muted.

And to top it off, my sub amp is on its way out; when cold it doesn't want to play and then it suddenly comes alive. It has been giving me intermittent issues for quite some time now and I think it's closer to needing repair.

Perhaps I overprocessed, but I can't help thinking that there's still something fundamentally wrong in my installation that is causing this problem. When I look at my baseline frequency responses for the L and R channels (see post #112), they just seem so far off from "normal"... sharp drop-off at 90 Hz on the left side, 80 Hz on the right (frankly, I don't think I even need to run crossovers), a roller coaster between 80 and 200 Hz... it just didn't seem right to have to boost the left side 10 db+ in the 180 - 200 Hz range, and to make similar drastic cuts on the right. They are both playing in equivalent (but opposite) enclosures, why should their output look so different in this range???

Maybe I'll try again from scratch as I get a chance this week, but based on results to date, I'm not confident I'm going to ever figure this out.

OK, venting done...

Anyone close to NJ who wants to come hear this and tell me what's wrong?


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## mojozoom (Feb 11, 2012)

My guess is that you've run into two things:

1) You've may have over EQ'd areas that are not minimum phase, creating mud
2) You also may not actually like the sound of the curve you've selected

When you start over, look at the minimum phase plot of the raw data and write down the areas that deviate from minimum phase. You'll want to minimize or completely avoid eq in those areas. My factory grills create non-minimum phase issues from 500-630 and from 2K-4K in my car.

If the bass isn't cohesive between the fronts one option might be to run rainbows between them and adjust TA on the left side as required to optimize the situation. Imaging probably would struggle afterward though depending on how far you shift it from correct impulse alignment. Maybe there's a happy medium there that you can find.


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## sqnut (Dec 24, 2009)

What is the sub to mid xover point and slopes? If you have the xover around 80 ish try lowering it a bit to 50~63 and see if that tightens the lower end. Since you have a passive xover between the mids and tweets, check if the passive has a switch to attenuate the tweeters. If so attenuate the tweets by 3-4db. 

If I look at the summed response @ 200 in post 112, 200hz is down only about 5db from 250hz, which is not that drastic. Your TA is sufficiently in the ball park at least for sub and mids. It is probably off between the mid and the tweet, since the tweet is also sharing the mids TA value although PLD's are different. However this may not be the cause of the problems right now. 

For a while just forget about all the curves and just focus on what you can do with your eq. It is very easy to get wrapped up in one area and get lost in the maze. Listen to a cd on your garage system and then in the car and note down the areas where your car lags.

You mentioned that vocals are subdued. The 500-1.25khz range is key for vocals. If this range is weak, the vocals will sound like they are submerged in the overall mix. Within this range play with 500/630/800/1 & 1.2khz play with one frequency at a time and see what it does. Basically get familiar with your eq and hear what impact each frequency has on the overall sound. 

I don't agree with the idea of not eq in the minimum phase areas. Talking about min phase in a car is a bit of an oxymoron. Hang in there and spend some time with the eq. Your ears will tell you right from wrong......provided you use them in short bursts

So raise a bit in the 500-1.25 range, cut further in the 3-8khz range


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## quality_sound (Dec 25, 2005)

mojozoom said:


> mooch,
> 
> After eq is the best as your eq impacts the shape of the phase curve. You could do a few iterations because the TA changes will impact the FR curve.


But TA will change what you need to EQ. It's a vicious cycle that will involve multiple rounds of both.


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## Hanatsu (Nov 9, 2010)

The weird thing is, my mid L-R response look much worse than yours, yet my setup sounded good after EQ. I don't run them much higher than 300Hz though. I never got any cancellations after combining the drivers.
Idk if I've asked it before, but have you checked polarity?


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## james2266 (Sep 24, 2009)

I will share my experience with this 'issue'. I once tried exactly this method of ta and eq (more or less) and I ended up with similar issues in the end. Trying to get matching left and right throughout the entire range of every set of speakers right down to the subwoofer, I found it really messed with the midbass localization for one and my imaging was just wrong. From talking to a few guys that have been doing this alot longer than I have been, I have come to the conclusion that this issue is being caused by the severe off axis nature (or maybe the severe axis difference between left and right) of a door installation. I also think that having them stealth behind a door panel can cause some ugly frequency shaping due to the factory grill and/or inner panel. 

I have had the best results yet with treating both midbasses as a pair and just eq for tonality. I don't even look at the individual speaker responses of my midbasses anymore. I also don't have them playing much past 300 Hz either. Now when it comes to my dedicated midranges and tweeters, I absolutely match them individually for frequency. I did notice that I had to reset ta once I did that however as suggested earlier. I will say that it really made my imaging 1000x more precise. Surprisingly I had to do nothing to my tweets other than drop a couple db at 16 kHz and lower the driver's by 2 db. My tweeters response is virtually identical. I wish I could say that about my midranges. That I have found is likely a bad enclosure issue more than anything but that is another discussion. 

Back to my midbass, I do have some heavy eq on them but both left and right eq settings are identical. The other thing that I found to be extremely valuable is to get an excellent recording of band limited 1/3 octave pink noise. I am thinking the next time I do this (probably soon if it ever warms up) I will probably set time alignment using that 800 Hz tone and then using the other tones associated with my midrange to eq left and right. I am wondering if I will end up with less eqing and better sound in the end. Would be interesting to take a left and right recording after to compare as well. If I ever get some warm weather here again and the gumption/time I will post up some stuff and mention my thoughts.

Another thing that I have been wondering about is the quality of the DAC doing the conversion. I listen to cds and things sound kind of flat but when I listen to the ipod, the vocals are screachy without dropping out a couple db in the upper midrange (1-4 kHz area). I know the ipod DAC is crap compared to the one in my Pioneer Z110BT and I really wish there was a way to bypass it. This might not be the right place to discuss this tho. I would be interested in others opinions on this however if anyone has any.


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## mooch91 (Apr 6, 2008)

Guys,

I've asked this one before, but I'm still not sure of the right answer:

For final frequency response shaping, including the sub, should I use stereo (uncorrelated) or mono (correlated) pink noise?

I get very different results depending on which I use.


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## Hanatsu (Nov 9, 2010)

Use uncorrelated (stereo).


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## mooch91 (Apr 6, 2008)

james2266 said:


> I will share my experience with this 'issue'. I once tried exactly this method of ta and eq (more or less) and I ended up with similar issues in the end. Trying to get matching left and right throughout the entire range of every set of speakers right down to the subwoofer, I found it really messed with the midbass localization for one and my imaging was just wrong. From talking to a few guys that have been doing this alot longer than I have been, I have come to the conclusion that this issue is being caused by the severe off axis nature (or maybe the severe axis difference between left and right) of a door installation. I also think that having them stealth behind a door panel can cause some ugly frequency shaping due to the factory grill and/or inner panel.
> 
> I have had the best results yet with treating both midbasses as a pair and just eq for tonality. I don't even look at the individual speaker responses of my midbasses anymore.


Interesting. Although I'm running a combo midbass/midrange, I had the same thought a number of posts back - that I was trying to make L and R look too much "alike" in the 80-300 Hz range. It seems that's one of the things that has made the midbass sound real funny. I'm also installed in the doors...


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## mojozoom (Feb 11, 2012)

mooch, maybe you should give Hanatsu's housecurve a try for fun. 

http://www.diymobileaudio.com/forum/1828589-post22.html


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## Hanatsu (Nov 9, 2010)

mooch91 said:


> Interesting. Although I'm running a combo midbass/midrange, I had the same thought a number of posts back - that I was trying to make L and R look too much "alike" in the 80-300 Hz range. It seems that's one of the things that has made the midbass sound real funny. I'm also installed in the doors...


In the ITD range of our hearing (up to 800Hz), time differences between L-R will be dominant in terms of localization (staging). Beyond 1600Hz (in the IID range) EQ is used to center the stage since we localize sounds based on intensity here. Between ~800-1600Hz both ITD/IID will be more or less 'active'.

This means; L-R EQ is most important above 800Hz. Some of dips and irregularities come from destructive interference, these cannot be EQed. These areas can be found by looking at the 'Excess group delay', let RoomEQ calculate minimum phase then check the group delay tab. If you got an eye for it, it can also be seen from the waterfall plots.

What I'm saying is that at low frequencies equal L-R FR might not be possible to archieve (without running into other issues)

Experiment; Try to EQ until you get close to perfect L-R EQ above 800Hz and don't touch EQ below that point at all. Listen to some track with female vocals and then some track with male vocals. How's tonality and staging?

Sent from my Samsung Galaxy 3 via Tapatalk.


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## james2266 (Sep 24, 2009)

Hanatsu said:


> In the ITD range of our hearing (up to 800Hz), time differences between L-R will be dominant in terms of localization (staging). Beyond 1600Hz (in the IID range) EQ is used to center the stage since we localize sounds based on intensity here. Between ~800-1600Hz both ITD/IID will be more or less 'active'.
> 
> This means; L-R EQ is most important above 800Hz. Some of dips and irregularities come from destructive interference, these cannot be EQed. These areas can be found by looking at the 'Excess group delay', let RoomEQ calculate minimum phase then check the group delay tab. If you got an eye for it, it can also be seen from the waterfall plots.
> 
> ...


Interesting and great advice especially for your type of 2 way door install. In a 3 way, depending on orientation of the midrange, I think you need to do left and right eq quite a bit lower but I will be experimenting with that on my next tune. I feel I have eq'd way too much on the midranges in my setup. 

I think I m going to go with the band limited pink noise and my ears only on the next left-right eq session. I will then you the rta for doing overall tonality. Should be interesting - that is if it gets warm enough here again

Another thought I have had is to do with the Schroeder frequency of a vehicle. By definition, it is more like the frequency where your vehicle becomes pressurized with sound waves. From reading, anything below this frequency, the readings one gets from an rta are pretty much consistant over a large area of space within the vehicle. I honestly think that makes left right eq below this point irrelevant especially with severely off-axis speaker locations. I would love others thoughts on this.


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## quality_sound (Dec 25, 2005)

james2266 said:


> I will share my experience with this 'issue'. I once tried exactly this method of ta and eq (more or less) and I ended up with similar issues in the end. Trying to get matching left and right throughout the entire range of every set of speakers right down to the subwoofer, I found it really messed with the midbass localization for one and my imaging was just wrong. From talking to a few guys that have been doing this alot longer than I have been, I have come to the conclusion that this issue is being caused by the severe off axis nature (or maybe the severe axis difference between left and right) of a door installation. I also think that having them stealth behind a door panel can cause some ugly frequency shaping due to the factory grill and/or inner panel.
> 
> I have had the best results yet with treating both midbasses as a pair and just eq for tonality. I don't even look at the individual speaker responses of my midbasses anymore. I also don't have them playing much past 300 Hz either. Now when it comes to my dedicated midranges and tweeters, I absolutely match them individually for frequency. I did notice that I had to reset ta once I did that however as suggested earlier. I will say that it really made my imaging 1000x more precise. Surprisingly I had to do nothing to my tweets other than drop a couple db at 16 kHz and lower the driver's by 2 db. My tweeters response is virtually identical. I wish I could say that about my midranges. That I have found is likely a bad enclosure issue more than anything but that is another discussion.
> 
> ...


All iPod DACs are actually damn near perfect. Tests have been done on every model since the second gen shuffle and they're all flat. I'm betting it is an issue with the ADC on your HUs iPod input.


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## Justin Zazzi (May 28, 2012)

Hanatsu said:


> Use uncorrelated (stereo).


I thought I knew the answer and reasoning behind this, but after searching some more, I'm not so sure.

Can you elaborate more on why uncorrelated pink noise is a better tool than correlated for measuring overall response, with multiple speakers playing?

Thanks!


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## Justin Zazzi (May 28, 2012)

cajunner said:


> so, when you get analog out of the iPod, and send it into the head unit, the head unit then has to reconvert it back into digital and do the digital sound shaping, then convert it back via it's internal DAC, into analog, where the deck uses analog pre-amp control to send it out to the amplifiers?
> 
> and this is how all head units that have some type of digital equalization circuitry do it?
> 
> wouldn't decks that are pure analog like a Nakamichi with the good pre-amp parts, be better sounding in the end if these digital conversions are audibly degrading the signal?


Ethan Winer has some very good articles on his website, and his book is a good introduction to everything audio. Essentially his experiment passes music through digital-analog-digital conversions a few times, and then twenty times. His simple, easy to read experiment is below.

Converter Loop-Back Tests

....

Also, this thread is fantastic.


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## Hanatsu (Nov 9, 2010)

Jazzi said:


> I thought I knew the answer and reasoning behind this, but after searching some more, I'm not so sure.
> 
> Can you elaborate more on why uncorrelated pink noise is a better tool than correlated for measuring overall response, with multiple speakers playing?
> 
> Thanks!


Ah the reason is simple. There are simply less interference between the sides with uncorrelated noise. If the two sides ain't playing the same 'tone' at the same time there's much less risk the two sides affect eachother. 

Correlated noise can be used to set T/A.

Sent from my Samsung Galaxy 3 via Tapatalk.


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## mooch91 (Apr 6, 2008)

Hanatsu said:


> Ah the reason is simple. There are simply less interference between the sides with uncorrelated noise. If the two sides ain't playing the same 'tone' at the same time there's much less risk the two sides affect eachother.
> 
> Correlated noise can be used to set T/A.
> 
> Sent from my Samsung Galaxy 3 via Tapatalk.


With uncorrelated, I'm getting an almost perfect summation of the L and R channels when I measure them individually and combined.

With correlated, I get that very sharp dip at 200 Hz, a very wide dip between 400 and 600 Hz, and a peak at 800-1200 Hz when measured combined. Individually they are near "perfect".

Sounds like I should stop trying to fine tune the correlated combined response and accept the uncorrelated response as "good".


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## Hanatsu (Nov 9, 2010)

mooch91 said:


> With uncorrelated, I'm getting an almost perfect summation of the L and R channels when I measure them individually and combined.
> 
> With correlated, I get that very sharp dip at 200 Hz, a very wide dip between 400 and 600 Hz, and a peak at 800-1200 Hz when measured combined. Individually they are near "perfect".
> 
> Sounds like I should stop trying to fine tune the correlated combined response and accept the uncorrelated response as "good".


This is also to be expected. You're seeing a comb filtering effect with correlated noise. Since uncorrelated noise basically is random sampled noise on each side they should just sum and give you +3dB louder amplitude overall.

Sent from my Samsung Galaxy 3 via Tapatalk.


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## Hanatsu (Nov 9, 2010)

james2266 said:


> Another thought I have had is to do with the Schroeder frequency of a vehicle. By definition, it is more like the frequency where your vehicle becomes pressurized with sound waves. From reading, anything below this frequency, the readings one gets from an rta are pretty much consistant over a large area of space within the vehicle. I honestly think that makes left right eq below this point irrelevant especially with severely off-axis speaker locations. I would love others thoughts on this.


Yes and no. 

Irrelevant, no. Less "need for" = yes. Tuning below the Schoeder frequency is easier in a sense, since the FR won't change very much if we move the head a bit. In my car this happens around 220Hz. We will still hear level differences if they're "too big". ITD is dominant here for localization so it will be less required to have an equal L-R frequency response. We must note however, that tonality will still be affected by irregularities in FR. There cannot be a 10dB difference at some frequencies (even in the ITD range) and not affect tonality (even if two drivers sum flat). Just because the cabin gets pressurized doesn't mean we can put a speaker just about anywhere and expect the same results.


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## mojozoom (Feb 11, 2012)

mooch,

I may have missed this, but can you describe your mic and body position during your measurements?

I found that holding the mic right next to my right ear when testing the right side (and vice versa for the left) gives the best results.

When I originally started testing I would have the mic held by the headrest and sit outside the car to tune. It didn't take long for me to figure out that the huge dips in right side FR I was finding in the low end were caused by reflections off the drivers side window. In actual listening, those cancellations wouldn't occur because my big fat head would be there to shield my right ear from them.


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## mooch91 (Apr 6, 2008)

mojozoom said:


> mooch,
> 
> I may have missed this, but can you describe your mic and body position during your measurements?
> 
> ...


The truck I'm measuring is a crew cab pickup, so I've always done my measurements from the back seat on the driver's side. I can set up the laptop and pre-amp for the mic back there and connect to the 360.3 which is under the seat.

I basically position the mic right on top of the driver's headrest, extended about 4" forward of the headrest which is approximately where my head is when listening. I have the mic "on axis" - pointing towards the windshield (not up). I move the mic from left to right and up down in a "figure 8" within about 6" of this point, continuously averaging all readings for at least 30 seconds, or until stabilized.

If I'm doing impulse measurements, I keep the mic fixed in this position.

I never considered having my body in the seat and what kind of effect that might have on the measurements...


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## mojozoom (Feb 11, 2012)

I was wondering if that was the case. If you think about it, you've probably been applying EQ to compensate for reflections that your head will actually be blocking when you sit in the car.


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## mooch91 (Apr 6, 2008)

mojozoom said:


> I was wondering if that was the case. If you think about it, you've probably been applying EQ to compensate for reflections that your head will actually be blocking when you sit in the car.


It was easy enough to run an experiment tonight. I took some measurements sitting in the front seat and sweeping the mic around my head. The high end definitely looked different but subbass, midbass, and lowe midrange were virtually the same as what I had before.


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## sqnut (Dec 24, 2009)

Can you list all the issues where you feel the sound is lacking? We can then try and address them one by one. Don't worry about the measurements you've done ok on that front. I wish I could sit in your truck and tune it for you

Edit : Can you post your subs response and a combined L&R mid response. Going to try and fix your lower end first.


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## Justin Zazzi (May 28, 2012)

Hanatsu said:


> Ah the reason is simple. There are simply less interference between the sides with uncorrelated noise. If the two sides ain't playing the same 'tone' at the same time there's much less risk the two sides affect eachother.
> 
> Correlated noise can be used to set T/A.
> 
> Sent from my Samsung Galaxy 3 via Tapatalk.


I _want_ to believe this, and the reasoning sounds pretty good. I see how this works and understand why it is believed to be superior.

However, we listen to music with a lot of correlated sound (centered vocals and instruments), and the left and right channels are never played in such a way to minimize interference. It was mentioned a few posts above, but you also cannot localize an image using uncorrelated noise tracks, so how can you measure and tune a system in this manner? I'm having a hard time relating this method of measurement (uncorrelated noise tracks) to what we hear when listening to any musical or vocal tracks.

Thanks!


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## Hanatsu (Nov 9, 2010)

Jazzi said:


> I _want_ to believe this, and the reasoning sounds pretty good. I see how this works and understand why it is believed to be superior.
> 
> However, we listen to music with a lot of correlated sound (centered vocals and instruments), and the left and right channels are never played in such a way to minimize interference. It was mentioned a few posts above, but you also cannot localize an image using uncorrelated noise tracks, so how can you measure and tune a system in this manner? I'm having a hard time relating this method of measurement (uncorrelated noise tracks) to what we hear when listening to any musical or vocal tracks.
> 
> Thanks!


Good point. Perhaps I should explain myself further. 

Correlated and uncorrelated PN will show similar results if both sides are perfectly in phase with eachother. The interference will most likely show up in the 200-600Hz area and will be altered by different delay settings. Uncorrelated will show you the "real" FR. The correlated PN will show you unavoidable dips in the FR, they cannot be EQed in the same manner because they are caused by destructive interference. Therefore, we disregard them somewhat. Also these frequencies will not necessarily be reproduced with the same amplitude and phase with music (in both channels). 

If the correlated PN/RTA show peaks in the FR (not very common IME) you 'might' wanna go halfway and bring down those peaks to a point between the correlated and uncorrelated FR plots. I do suggest to ignore all the dips in the correlated FR plot though.

Sent from my Samsung Galaxy 3 via Tapatalk.


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## mooch91 (Apr 6, 2008)

Guys,

I think it's time I take a short break from this effort... It's actually gotten a bit unhealthy for me, I think. I'm spending just about every waking minute behind the wheel, in the cold, trying to tune this system, and I feel like I just keep going in circles. I need a break. Plus, I think there are just too many anomalies that I need to investigate before I continue tuning.

For one, my sub amp is really taking a downward turn. I need to smack it around a bit to get it to start playing each morning (it powers up fine, it just doesn't play, or plays very muted, until I literally hit the amp or hit a bump in the road). I've been noticing very dramatic frequency response changes (+/- 5 - 10 dB at some frequencies) from the sub channel, even as I've been tuning. I think it's sort of a waste of time to continue to tune with this type of issue going on.

I'm still bothered by some issues with amp gains that I don't know could be indicating some sort of a problem as well. My HU is 2V output, the 360.3 is converting to an 8V output, and yet I still feel like my gains are ending up completely mismatched for the signal I'm working with. I have both amps set to the 200 mV-2V input range, front channel amp is set at minimum (2V) and sub amp gain is halfway up. I still find I'm running the volume on my HU way up (3/4) for moderate volume and, for some recordings, all the way to 90% to achieve moderate. Maybe I don't completely understand line level signals, but I would have thought an 8V pre-amp signal should match with the 800 mV-8V range on my amps and the gain would be near minimum (8V) for each. At the 8V input range, I have to crank the gains way up to get reasonable volume.

The midbass response in the doors has me a little concerned too. The Pioneer set I've got were claimed by many to be "midbass monsters", but the response I hear (and see on RTA) never seemed to reveal the same. Maybe it's the particulars of my installation (stealth behind door panels/grilles), but I've always been underwhelmed. I would love to revisit the installation of these to see if there is anything wrong, or could be done better. I know I need to do something different with the tweeters for sure at some point. I installed them behind a heavy perforated plastic grille (factory), but I never had a good way to aim them and I think that's why my responses always drop off so dramatically at the top end.

I've been holding off on completing the install of the 360.3 until I was sure I had everything right; I've moved RCAs and other connections so many times to try different things and I didn't want to finalize it until I was sure things were good. I've got trim panels off from when I installed the new sub and some wiring that needs to be cleaned up. I really could use a warm weekend to take out my back seat and permanently mount and clean everything up. I'd love to tear it _all_ out, rewire, and go fully active, but I just don't think the juice is worth the squeeze for that effort right now. I've removed and reinstalled so many things so many times over five years that strands are falling off the ends of wires, trim panels are not fitting perfectly any more, and I've ended up with more hot glue holding things together than I care to have.

Bottom line, I think it's important for me to clear up some of these things and take a break from tuning before continuing. I've appreciated all of the time you guys have given me to date, and I hope I can jump back in with some more detailed discussions in a few weeks. Ideally, I'd like to find someone local with a good ear who could help me with some critical listening, too, to help manage my expectations overall.

Stay "tuned"...


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## sqnut (Dec 24, 2009)

I empathize with you. I was where you are, probably further back, a few years back. Lunch time tuning breaks, taking chunks out of family time to tune, tinkering at every red light while driving, I was obsessed. The biggest frustration was that despite of the time and efforts, the sound pretty much sucked. I read tons of stuff on various forums, a lot went over my head and what I tried to implement didn't work. 

If I look back, I think I spent a good three years chasing my tail thinking I was getting somewhere. The problem was I was chasing and worrying about stuff that wasn't relevant in the big picture. So yeah I cut my door panels so that the speaker wouldn't be behind the stock grill (sound still sucked), tore up and rewired the system a few times, used 'special' cables etc. I mean you name it and chances are I had tried it.

So yeah get the sub amp fixed and do a once over on the connections just to make sure. The way you describe your gains is pretty normal. You can turn up the gains at the amp a bit if you want. If your hu is rated for 2v under normal operation it's probably putting out ~1v, the 8v at 360.3 is probably 3v in real terms. The rated volts on hu's are a bit like the peak output rating on speakers, i.e. meaningless. Yes the 360.3 may put out 8v but that's at full volume with all processing maxed out etc. 

Once you are ready and have given your system a once over, forget about all the curves, how it measures and all the other gizmo glib that you may read about. Use your eq to get the tonality right. Don't get lost in the maze and dead end alleys like I did.

Take a break, spend time with the family and come back charged. I started making progress when I junked all the 'other stuff' out of my head and just focused on getting it right. Most of the tuning cd's have solo tracks i.e. solo drums, acoustic guitar, cello etc etc. Pick an instrument, hear it on a 2ch or via headphones and then try and dial that sound in without worrying what its doing to the overall curve.

I search and post the chart that gives the fundamentals and harmonic range for a whole lot of instruments as well as male and female vocals. So now you're tuning based on the sound from one instrument and you know the range you're playing in. Get a couple of instruments dialed in and then listen to music.......I think you will be surprised with the results. BTW the pio mids are monsters with the low end. A very good pair of components. 

When you're giving the once over, take the leap and go fully active . Meanwhile enjoy the break.


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## sqnut (Dec 24, 2009)

Interactive Frequency Chart - Independent Recording Network

Here you go


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## mooch91 (Apr 6, 2008)

Guys,

I said I'd stay away - I couldn't.

Spent some time tuning last night and again tonight.

I've tried a few different things, none of which panned out. I'm trying hard not to focus on the curves, but the reason I bought the measuring gear is because my ear is not trained well enough to allow me to do without it. I have a tendency to target fundamental frequencies, as opposed to harmonics which are more likely the issue, when things don't sound right.

I've tried not over-exaggerating the bass, adding only about +10 dB off my baseline. I've tried to reduce the treble, rolling off more than 8 dB from 2000 Hz. I've been round and round again trying to get some level of liveliness and warmth from this system and it just ain't happening, no matter what I try.

I'm back to being convinced there has got to be something fundamentally wrong with my setup. Or my expectations are just way too high. There is just no way this should be sounding this bad.

If I boost the sub, the bass sounds boxy, very mechanical. If I add more in the 80-200 midbass area, the bass gets boomy. There's never any warmth or definition to the bass line of the music. Hell, I noticed the 6" paper speakers on my Toshiba rear projection TV had more warmth and definition to the bass when I was watching a music program last night... This is definitely one of the things that's been consistent with every tune I've created.

Figuring it's got to be the treble that's masking the midrange, I've tried to roll it off a bit more than I have been. Although it's no longer as piercing and harsh, I'm starting to lose clarity and definition in the music. Sparkle is dwindling. Female vocals aren't sounding present. Cymbals are disappearing.

Anyway, here's my latest overall curve. This is with uncorrelated pink noise which tends to show about 3-4 dB lower from 20-160 Hz than correlated pink noise. I'm back to measuring from the back seat (tried the front seat, with me in place, but found it impossible to get good average measurements positioning the mic by my ears, figured the error with me out of the seat had to be less than the inconsistency trying to do it the way I was). Mic pointed forwards (mic pointing up gave a terribly bright outcome).


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## subwoofery (Nov 9, 2008)

Dynamics usually comes from the 1kHz-4kHz range - try to get this range nice and smooth. 
It can sound counter intuitive but try turning off your subwoofer and listen and tune your system with it off - for a week 
Try to make your system as lively as possible without boosting the midbass too much... Just make sure you have no peaks or dips in your freq - maybe focus on phase and T/A this time

When you're happy with your system, turn the sub back on and try to level it with the rest of the system 

That's usually what I do when I can't find what's wrong with my system... Subwoofer freqs might be masking problems happening way up in your freq

Kelvin


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## Hanatsu (Nov 9, 2010)

It's hard to give any useful advice without listening to the system in person. 

How does it sound if you open a door/window? Try measuring the sub outside the car. You might have some weird acoustical issue related to your small cabin volume. Would be interesting to see the transfer function of the car.

Post a plot from the "Delay" tab. Easy to see environment related problems there.

And btw. Post a screenshot from the distortion tab as well, 2nd-5th order 20Hz-20k

Sent from my Samsung Galaxy 3 via Tapatalk.


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## sqnut (Dec 24, 2009)

mooch91 said:


> I've tried a few different things, none of which panned out. I'm trying hard not to focus on the curves, but the reason I bought the measuring gear is because my ear is not trained well enough to allow me to do without it. I have a tendency to target fundamental frequencies, as opposed to harmonics which are more likely the issue, when things don't sound right.


Two things here and you are already doing one. First step is to spend the hours listening and training your ears. From getting a fix on how it should sound and getting that etched in your head, to the ability to accurately differentiate between better and worse in small increments. You are already doing this bit.

Next you need to figure out what cutting / boosting each frequency does to the sound. What part of the sound does it effect and how does it change the sound? Boost a frequency 2-3db, how has the sound changed? Come back to the starting point and now cut 2-3db again, how has the sound changed? Do this over one octave at a time. Basically try and get an idea of how each octave affects the sound and within that what each frequency does. 

Once you have this in place then merge the two. Pick the defects you're hearing with how you can fix it at the eq. It's going to take time so just hang in there. If the fundamentals 

If you have the fundamentals in place across the octaves, the harmonics will largely be in place. You don't need to tune for harmonics per se. 



mooch91 said:


> I've tried not over-exaggerating the bass, adding only about +10 dB off my baseline. I've tried to reduce the treble, rolling off more than 8 dB from 2000 Hz. I've been round and round again trying to get some level of liveliness and warmth from this system and it just ain't happening, no matter what I try.
> 
> I'm back to being convinced there has got to be something fundamentally wrong with my setup. Or my expectations are just way too high. There is just no way this should be sounding this bad.
> 
> ...


If it sounds like a cheap radio, try playing some in the 300-800 range. If this range is too hot then the sound would have a honking / telephony kind of quality. Kinda like the sound from a cheap radio. Cutting this range should also flesh out a bit more at the lower end. If you cut too much it will make vocals and instruments sound like they are mushed together. They lose their individual identities. 

1-4khz helps with dynamics as Kelvin mentioned. However too much at 2-2.5 and the piano will have a honking sound. Play a piano solo and see if this is the case. On your graph 2khz is at the same level as the 400-800hz. So its possible the the 2-3khz range is hot. Try and place this range about 3-4db lower. Which means the roll off will start around the 1-1.25khz mark. 4-6khz would then be lower etc.


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## mooch91 (Apr 6, 2008)

Thanks guys. It will take me some time to process all of what you've commented to try a couple of things out.

A couple of other observations I wanted to make, not necessarily ones I've just realized in the past couple of weeks, but since I've started playing with this system.

The first is that my system seems to be really sensitive to music genre. There are a few recordings that I can have sounding decent at just about any tuning setup - virtually any of the reference discs (Focal, Marantz, etc.) and even some contemporary recordings like Clapton's unplugged, sound fairly good. I've noticed acoustic recordings usually sound decent. In contrast, anything with an ounce of compression falls apart so fast. I've commented in these forums before that I can't play anything metal without it sounding like noise, and even many decent rock recordings (classic or modern) are challenging to listen to. I would say that 80% of my collection (iPod or disc) sounds "bad" on my mobile stereo while I get better than 80% sounding good on the basic home system.

I know that recording quality generates a lot of debate on these forums, in particular the mp3 vs. lossless discussions, as well as compression discussions. I agree that there are some real crap recordings and that I shouldn't expect a great sound out of a 128 kbps mp3. But at the same time, I would expect that a library of 320 kbps mp3s (of which mine are) as well as CD recordings should sound decent on any system without major adjustment. At least that's been my experience with my home system the majority of the time.

Are there any factors in an install or tune that could contribute to the observations I've described?


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## sqnut (Dec 24, 2009)

Once you have the system sounding accurate, it will be so across genres. 

Compressed recordings will generally sound louder than the more dynamic ones. But the lack of dynamics, that sense of high and low, will leave you feeling disconnected from the music. Dynamics give that sense of being there and hence greater connect. 

If you can sense this on your system then, you've come some way already . It's a slow process. If metal sounds bad on the setup then, I'm quite sure the 2-4 khz range is one of the issues.


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## mooch91 (Apr 6, 2008)

Is it really possible that my un-EQ'ed curves are this far off from "flat" (green - left; red - right)?









Just curious to know if it's "normal" to have *15 dB swings *across the frequency range.

If this *is* normal, how do folks who advocate "no EQ necessary" possibly straighten a response like this out?


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## masswork (Feb 23, 2009)

mooch91 said:


> Is it really possible that my un-EQ'ed curves are this far off from "flat" (green - left; red - right)?
> 
> 
> 
> ...


Yep, looks normal to me.

Well, multi speakers, crossover and placement may help a bit.


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## Hanatsu (Nov 9, 2010)

EQ IS required in ALL cars. Fact. People who say they don't need it... well they need to learn to use it.

It's not uncommon with narrow dips that causes 15dB differences L/R... which is exactly why we need EQ. However, EQ can also destroy the sound if set incorrectly. I can make any system sound like **** by messing up EQ ;P

Sent from my Samsung Galaxy 3 via Tapatalk.


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## mojozoom (Feb 11, 2012)

I still think there's some sort of intermodulation distortion going on here. Honestly, I don't see how you could be off so far tonally that you can't listen to rock. It seems like it has to be deeper.

Have you tried the TA method outlined in "Precision time alignment using noise tracks and your ears"?

http://www.diymobileaudio.com/forum/how-articles-provided-our-members/96196-precision-time-alignment-using-only-noise-tracks-your-ears.html

This method focuses on using TA to eliminate intermodulation distortion by learing how to listen for it and adjust TA accordingly.


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## sqnut (Dec 24, 2009)

It's purely about dialing in the tonality. It's not a system issue nor one of intermodulation distortion. His sound is not bad, just not as good as he wants.


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## mooch91 (Apr 6, 2008)

Folks,

Maybe you can help me understand the outcome of a little test I did today. I was trying to get the time alignment set with my ears, using the thread mojozoom pointed me to (I'll be damed if I can hear what's being described - but that's a whole other topic). As part of that process, I reversed the phase of my subwoofer via the 3sixty.

Here's my "normal phase" sub (I boosted the level after reversing it which is why it's so high vs. my baseline; I've been running it about 5dB lower):









Here is my "reverse phase" sub:









When I reverse the phase, there is clearly some mad cancellation in the 80 - 100 Hz range (I can actually hear it when playing tones - at the driver's seat, they practically disappear). I think I've observed this before. Weird part is, it actually sound infinitely _better_ than the normal phase output (not _outstanding_, but much _better_). The bass seems "deeper" (more "depth" and less "slap").

How can this be? Surely, running my setup with a cancellation this big can't be "right", but what do I need to do to the normal phase situation to get similar results?

Almost seems like I'm looking for a target curve flat to 100 Hz, with a sharp rise to the sub-bass? Certainly not a target curve I've ever seen described here or elsewhere in RTA threads.

Or is it more that's going on than just frequency response?

Thoughts?


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## mojozoom (Feb 11, 2012)

IIRC Andy W.'s curve concept was start the flat section at 160 hz after ramping down the bass. I know he mentioned in one thread that you were asking for mud if you aimed out further than that (like your 300 hz point in the red curve).

http://www.diymobileaudio.com/forum/technical-advanced-car-audio-discussion/131029-target-curve-comparison.html


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## mooch91 (Apr 6, 2008)

mojozoom said:


> IIRC Andy W.'s curve concept was start the flat section at 160 hz after ramping down the bass. I know he mentioned in one thread that you were asking for mud if you aimed out further than that (like your 300 hz point in the red curve).
> 
> http://www.diymobileaudio.com/forum/technical-advanced-car-audio-discussion/131029-target-curve-comparison.html


It will be interesting to see if I can reproduce the sound by roughly matching the curve with the sub at normal phase.


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## Woosey (Feb 2, 2011)

May i ask how your midbasses are mounted?


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## mooch91 (Apr 6, 2008)

Woosey said:


> May i ask how your midbasses are mounted?


In stock locations in the doors, essentially facing each other.


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## Woosey (Feb 2, 2011)

Thanks, how thick are the spacers? Are they "chamfered"from the inside?


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## mooch91 (Apr 6, 2008)

Woosey said:


> Thanks, how thick are the spacers? Are they "chamfered"from the inside?


About 3/8", no chamfer.


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## Woosey (Feb 2, 2011)

mooch91 said:


> About 3/8", no chamfer.


This could mean your drivers could be compressing air behind the cone causing problems..


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## mooch91 (Apr 6, 2008)

Woosey said:


> This could mean your drivers could be compressing air behind the cone causing problems..


Would this be significant? I know that the 6 3/4" opening is not completely aligned with the 5x7 cutout, which would be leaving a little concentric "edge" of sheet metal on the inside of the mount. I just never anticipated this would have a significant effect.


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## Woosey (Feb 2, 2011)

mooch91 said:


> Would this be significant? I know that the 6 3/4" opening is not completely aligned with the 5x7 cutout, which would be leaving a little concentric "edge" of sheet metal on the inside of the mount. I just never anticipated this would have a significant effect.


A 3/8" baffle could also block the ventilation of the driver itself, not completely but partly.. This could be a troublemaker... 

I asked this because you mentioned that anything metal sounds like noise...


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## Hanatsu (Nov 9, 2010)

mooch91 said:


> Folks,
> 
> Maybe you can help me understand the outcome of a little test I did today. I was trying to get the time alignment set with my ears, using the thread mojozoom pointed me to (I'll be damed if I can hear what's being described - but that's a whole other topic). As part of that process, I reversed the phase of my subwoofer via the 3sixty.
> 
> ...


The main issue is normally just the frequency response, the smaller listening space you got, the worse it gets IME. Post a waterfall/delay plot between 20-500Hz, 0-300ms, also a distortion plot (only accessible when you perform a sweep). Any additional issues should show up in those. Intermodulation distortion (IMD) is a long shot imo, you cannot measure it easily either. Chamfering the MDF baffle sometimes improves bass performance, never ran into issues related to not doing it though.

If it sounds better with the sub in reverse I'd say the main issue perhaps lies in the 100-200Hz area. Hm... try;

Cut the 30-50Hz area 3-4dB, cut 120-250Hz around 4-5dB, cut 400-1200Hz 2dB, cut 2000Hz Q5 -2dB. Boost 3000-10000Hz 2,5dB.

Something like this (you can have more bass below 60Hz if you prefer):


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## Woosey (Feb 2, 2011)

Here I made a quick drawing of how I think the situation is at the moment..

Correct me if I'm wrong..

If this is your situation, ( the bit sheetmetal not included ) then I really can recommend fixing this first... If it doesn't help, the driver can at least breathe more easy..

Do you have some absorbing material behind the driver?


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## mooch91 (Apr 6, 2008)

Woosey said:


> Here I made a quick drawing of how I think the situation is at the moment..
> 
> Correct me if I'm wrong..
> 
> ...


Maybe this could explain what I've always thought was poor performance from what is supposed to be a decent mid bass?

No sound absorbing material behind the speaker.

Sent from my mobile device.


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## Woosey (Feb 2, 2011)

mooch91 said:


> Maybe this could explain what I've always thought was poor performance from what is supposed to be a decent mid bass?
> 
> No sound absorbing material behind the speaker.
> 
> Sent from my mobile device.


who knows.. 

Absorber is also recommendable, those trucks often have pretty parallel doorpanels, the backwave can also influence the way it behaves..


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## mojozoom (Feb 11, 2012)

Now we're getting somewhere. IMO, stock grills can cause non minimum phase issues. Especially if the alignment to the driver is off.

http://www.diymobileaudio.com/forum/technical-advanced-car-audio-discussion/144182-restrictive-stock-speaker-grills.html


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## sqnut (Dec 24, 2009)

mooch91 said:


> Folks,
> 
> Maybe you can help me understand the outcome of a little test I did today. I was trying to get the time alignment set with my ears, using the thread mojozoom pointed me to (I'll be damed if I can hear what's being described - but that's a whole other topic). As part of that process, I reversed the phase of my subwoofer via the 3sixty.
> 
> ...


With your sub in normal phase, your sub and mids are in phase hence there is summing in the range that both drivers are playing. You need to cut 60-100, I've mentioned that on more than one occasion. With your sub in reverse phase the same range is now 180 deg out of phase from the sub and mids and hence you're getting cancellations and sharper roll off. You can achieve the same result by keeping the sub in phase but on a steep slope ~36-48 db/oct and cutting the 60-100 range. I would go this route. Also note how with the reversed sub you get a hump at 200-300. 

When you play with the eq do you boost/cut at specific frequencies or do you just define a target curve and let the 360.3 do the rest? If so how are you going to understand what effect each frequency has on the sound? The curve that sounds best in your car is undefined as yet. So we can either take random potshots till we hit the lodestone or you can forget about curves for a bit and play with the eq one frequency at a time and figure out what each does and construct the overall curve by hearing and tuning your way there. 

To me that is way more relevant than stuff like IMD, mounting of mids and the stock grills over the speaker etc.


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## Woosey (Feb 2, 2011)

sqnut said:


> To me that is way more relevant than stuff like IMD, mounting of mids and the stock grills over the speaker etc.


I don't agree on this... First the driver has to be mounted correctly so you can rule that out... 

Good mounting is the foundation of a good install... period.


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## sqnut (Dec 24, 2009)

The front door on the Ford has a brace for a 5x7. Initially my mid was mounted via a 1/2" mdf ring and a part of the rear cone (maybe 10%) was blocked by metal. Metal was about 3/4" behind the cone, got it cut about a year after the install thinking I'd hear a difference. No difference. I agree that technically it's better to have the install done right. 

Still maintain that OPs issue is not related to install or the lack of a chamfered mounting ring, that's all that I'm saying.


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## mojozoom (Feb 11, 2012)

He's tried alot of things though, even adding a DSP to the mix, and it sounds like his fundamental issues still remain. With that in mind it seems like the problems would have to be caused by something that's been a constant throughout the process, and the speaker mounting situation falls into that category.

Easy to check though, just pull the interior door panels, seal the gap between the window and door structure with a few layers of duct tape, and give it a listen. Can't hurt to try.


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## sqnut (Dec 24, 2009)

mojozoom said:


> He's tried alot of things though, even adding a DSP to the mix, and it sounds like his fundamental issues still remain. With that in mind it seems like the problems would have to be caused by something that's been a constant throughout the process, and the speaker mounting situation falls into that category.
> 
> Easy to check though, just pull the interior door panels, seal the gap between the window and door structure with a few layers of duct tape, and give it a listen. Can't hurt to try.


As far as tuning goes he's just scratched the surface. Here's the problem. The 360.3 gives 31 bands of eq per channel. With all channels running, that is more than 4.1002125........e+171 possible combinations on the eq one of which will be 'the one'. Let's say about 50 would sound decent to good. Either ways it's like looking for a needle in a haystack......unless you get a grip on how to use the eq. That is the real problem.


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## Woosey (Feb 2, 2011)

sqnut said:


> The front door on the Ford has a brace for a 5x7. Initially my mid was mounted via a 1/2" mdf ring and a part of the rear cone (maybe 10%) was blocked by metal. Metal was about 3/4" behind the cone, got it cut about a year after the install thinking I'd hear a difference. No difference. I agree that technically it's better to have the install done right.
> 
> Still maintain that OPs issue is not related to install or the lack of a chamfered mounting ring, that's all that I'm saying.


You give the answer yourself... your vent was about 10% blocked, in this situation it is more than that.... i'd still give it a try...


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## sqnut (Dec 24, 2009)

Woosey said:


> You give the answer yourself... your vent was about 10% blocked, in this situation it is more than that.... i'd still give it a try...


If there is an issue it should be addressed, I'm with you on that. But in the here and now that this thread is and keeping in mind the OPs sound quality vs where he wants to be, working on dsp skills will give better results than an install modification. That's all. 

Correct the install, but right now its not the cause of current issues. Better to focus on one thing for now.


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## subwoofery (Nov 9, 2008)

Still suggest the OP works on his tuning without the sub... 
Not having correct phase up high (above about 1.6kHz) can have a negative effect on how you perceive low frequencies... 

Kelvin


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## mojozoom (Feb 11, 2012)

mooch,

The only way to get a curve that flat with a 2-way passive system using factory mounting locations is to apply EQ in places where you shouldn't be. I know because I did it for a few years.

It's a fact that if you apply too much EQ to the non minimum phase areas of the response you'll get distortion. It's easy to determine where those areas are, and although it's hard to resist the temptation, you need to avoid applying significant EQ there.

You can start clean with a flat EQ, sweep it in REW, and go to the GD tab and Generate Minimum Phase. Then look at the Excess Group Delay plot. You should get something like this:









Areas that are pretty much flat are close to minimum phase, and sloped ares aren't. In the above example, you'd want to avoid 100-250 hz, 630-1250 hz, and 1600-2500 hz.

If you work your target curve with these limitations in mind, you should have a really good starting point to start tweaking tonality based on sqnut's recommendations.

I've got more detailed test information on non minimum phase EQ effects in my car that I'll post soon in the How To section, including some distortion tests.


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## mooch91 (Apr 6, 2008)

Guys,

A lot of great thoughts here. I'm sure each one of them could use improvement in my system and I will continue to address them over time.

I think I may have made some progress today with this new information from the "reverse phase experiment" and some of the EQ thoughts you've given me. I don't want to claim victory yet (I've done that too many times in the past only to be disappointed the next day).

I re-tuned flat down to near 160 Hz and then gave a big boost to the sub. Sort of simulated the curve I had when I reversed the phase on the sub. I've actually got my sub at 65/24 and my mids at 100/24, to cut off a bit of the peak I get from these guys down low. 

So far - wow! I happened to play around with Focal disc 2, tracks 45+ and couldn't believe the dynamics I was getting. The shattering bulb track actually scared me.  

Here's where I'm at - and I think I am learning a bit more about proper EQ and the various frequencies at issue in my system:









Wondering if I've had "mud" by trying to simulate some of the more popular curves. I'm thinking I like a significant bass boost in my sound, but I'm figuring this has to be applied carefully. In the form of boost for 60 Hz and below with a much sharper roll-off than most of the popular curves suggest.


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## quality_sound (Dec 25, 2005)

How's the midbass impact? It looks a little depressed.


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## mooch91 (Apr 6, 2008)

quality_sound said:


> How's the midbass impact? It looks a little depressed.


It sounds so much more "right" to me. Maybe that means less accurate, I don't know, but it actually _has_ impact which is something I haven't experienced with the prior tunes.

Need more time behind the wheel to judge.


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## quality_sound (Dec 25, 2005)

Do you have any Michael Jackson or Dire Straights? You'll know pretty quickly if it's missing. 

I'm glad you're making progress.


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## mooch91 (Apr 6, 2008)

quality_sound said:


> Do you have any Michael Jackson or Dire Straights? You'll know pretty quickly if it's missing.
> 
> I'm glad you're making progress.


I will give them both a shot tomorrow.


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## ErinH (Feb 14, 2007)

mooch91 said:


> It sounds so much more "right" to me. Maybe that means less accurate, I don't know, but it actually _has_ impact which is something I haven't experienced with the prior tunes.
> 
> Need more time behind the wheel to judge.


that also could be because there's less midbass overall in levels, which makes the modal issues less apparent. if this is the case, correcting the modal issues allows you to raise your level or alter your curve and provide a better transition from sub to midbass to midrange.


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## sqnut (Dec 24, 2009)

+ 1 on Dire Straits. Go with Romeo and Juliet and Skateaway, off the album Making Movies. The lower end on R&J is almost 100% midbass.


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## mooch91 (Apr 6, 2008)

sqnut said:


> + 1 on Dire Straits. Go with Romeo and Juliet and Skateaway, off the album Making Movies. The lower end on R&J is almost 100% midbass.


"Private Investigations" comes with me for the Monday morning ride.

So far, so good. Played the system for my Dad after Easter dinner today. Granted, he's not "one of us", but he commented that he's "never heard anything like it".

The curve may not look "right", but it's working for me so far...


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## mooch91 (Apr 6, 2008)

Midbass a little light this morning (strange how it can sound so good standing still with the engine off, but start the engine and get moving and it sounds so different). My sub amp was acting up again, so that might have been part of the problem. Going to continue to listen for a while and them maybe increase the midbass slowly (I can add a dB or so to each side with a Q of 2 around 150 Hz to boost it up a bit) to see if I can get some reinforcement without it falling to crap.


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## sqnut (Dec 24, 2009)

Road and engine noise will cause cancellations in your 80-300 range. You can fatten that range but then the sound when you're parked is going to be flabby/boomy. You'll have to try and find a middle path. Not too light while on the move and just a bit extra when parked.


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## Woosey (Feb 2, 2011)

Doesn't this look alot like your response?http://www.diymobileaudio.com/forum/448989-post18.html


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## mooch91 (Apr 6, 2008)

Woosey said:


> Doesn't this look alot like your response?http://www.diymobileaudio.com/forum/448989-post18.html


Ironically, it does. 

I must not be that far off...


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## mooch91 (Apr 6, 2008)

Wanted to ask you guys a little about time alignment.

So far, I've had my left and right mids time aligned. I did it via distance measurements and put about 1.48 ms delay on the left side (about 20" path length difference between the two at the driver's seat).

Never had any luck getting the sub time aligned - my earlier experiments put it at 0 ms delay (see earlier in the thread).

I gave a shot to Hanatsu's precision time alignment method using REW with loopback measurements.

I took three measurement sweeps from 60 - 600 Hz. Green is left, red is right, and blue is sub.









Actual measurements to the first significant peak for each are: 7.59 ms for left, 9.01 ms for right, and 15.01 ms for sub.

Interestingly, the measured difference of left to right is 1.42 ms, almost exactly what I physically measured with distance.

The measured value for the sub is way "off" from its physical location in the cab. The right mid is actually the physically furthest driver and the sub and left mid are about the same distance, 20" less than the right mid.

Just curious about this result and wondering if it can be trusted for time alignment?


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## quality_sound (Dec 25, 2005)

mojozoom said:


> mooch,
> 
> The only way to get a curve that flat with a 2-way passive system using factory mounting locations is to apply EQ in places where you shouldn't be. I know because I did it for a few years.
> 
> ...


How are you getting the generate tab to work? Mine isn't lit up and I can't, for the life of me, figure out what I need to do get it to work. 

More troubling is that even with the mic calibration applied my curve with no sound isn't flat.


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## Hanatsu (Nov 9, 2010)

mooch91 said:


> Wanted to ask you guys a little about time alignment.
> 
> So far, I've had my left and right mids time aligned. I did it via distance measurements and put about 1.48 ms delay on the left side (about 20" path length difference between the two at the driver's seat).
> 
> ...


Try again with the same bandwidth. Try 110-120Hz for example, the impulse peaks should look more alike. The method can be trusted, T/A;ed my car and a friends cars with this method, perfect T/A both times.

Note that crossovers and stuff affect the delay, might account for the distance difference you're seeing.


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## mooch91 (Apr 6, 2008)

Hanatsu said:


> Try again with the same bandwidth. Try 110-120Hz for example, the impulse peaks should look more alike. The method can be trusted, T/A;ed my car and a friends cars with this method, perfect T/A both times.


They were taken at the same BW, 60-600 Hz. I'm going to narrow it a bit and overlap a little more, say 40-250 Hz which should be a range they are both playing.


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## Hanatsu (Nov 9, 2010)

quality_sound said:


> How are you getting the generate tab to work? Mine isn't lit up and I can't, for the life of me, figure out what I need to do get it to work.
> 
> More troubling is that even with the mic calibration applied my curve with no sound isn't flat.


You are using the sweep method right? RTA/Pink noise won't work...

If you're doing sweeps it might be a bug, using the latest beta update?


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## quality_sound (Dec 25, 2005)

Hanatsu said:


> You are using the sweep method right? RTA/Pink noise won't work...
> 
> If you're doing sweeps it might be a bug, using the latest beta update?


No, just standard pink noise/RTA. It IS the neweest version though so it might be a software issue.


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## mooch91 (Apr 6, 2008)

Hanatsu said:


> Try again with the same bandwidth. Try 110-120Hz for example, the impulse peaks should look more alike. The method can be trusted, T/A;ed my car and a friends cars with this method, perfect T/A both times.
> 
> Note that crossovers and stuff affect the delay, might account for the distance difference you're seeing.


I tightened up the bandwith to 100 - 125 Hz. This should be in the overlap between mids and sub, favoring the mids. I'm able to get my T/A dead on for the mids (fronts) as you can see (green and red in the attached). 

Still don't know what to do with the sub (blue) - currently no delay. Not sure if I'd want to line up the 5-10 ms peaks (which would delay the sub) or the 15 ms peaks (which would delay the others relative to the sub).

I'm thinking the sub is probably "close enough" as it stands, which confirms the results I had from "rainbow plots" earlier.


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## Hanatsu (Nov 9, 2010)

So how does it sound now? Did the image improve? The sub look like it's aligned now. The big peak is close enough.

You can do the same for tweets/mids btw. Try 1500-2000Hz or so 



Sent from my Samsung Galaxy 3 via Tapatalk.


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## mooch91 (Apr 6, 2008)

subwoofery said:


> Still suggest the OP works on his tuning without the sub...
> Not having correct phase up high (above about 1.6kHz) can have a negative effect on how you perceive low frequencies...
> 
> Kelvin


Kelvin,

So how should the two-way front stage sound without a sub? Right now my sub appears to be doing most of the midbass duty. When I run without it, the system can be very harsh. Very little midbass and the highs are piercing. Bring the sub back in to the mix and it doesn't sound "right", but it seems to calm the treble down.

When I was trying to get more midbass from the front stage previously, it seemed to really get muddy and distorted fast.


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## mooch91 (Apr 6, 2008)

Hanatsu said:


> So how does it sound now? Did the image improve? The sub look like it's aligned now. The big peak is close enough.
> 
> You can do the same for tweets/mids btw. Try 1500-2000Hz or so
> 
> ...


Image seems to be fine, but things are still harsh on the treble side and the sub/midbass still doesn't feel right. I threw caution to the wind a couple of days ago and just started tuning by ear. Turned the RF Punch EQ on the 3xisty.3 up until I was getting the "feel" I expected from the sub (essentially amounts to a 3-4 dB boost at 45 Hz) but it got localizable really fast. Tried making very broad and significant cuts at around 2kHz and 5 kHz to bring down some of the treble but still had harshness. Turned off the sub for a while and I feel like all I've got it is a pair of tweeters screaming at me when I turn it up, not a really balanced sound across the range - hence the reason for my question above.

I dunno, feeling like I'm back to going around in circles...


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## Hanatsu (Nov 9, 2010)

It shouldn't sound that bad with the frequency response you got. I think you might actually have other issues. 

Do a distortion measurement, I'm pretty sure you got issues there. Tuned a car recently, it measured fine but sounded harsh as crap. After a while I made a distortion test and found out that the system had like 4-5% tall order distortion products in the low midrange at reasonably low volume. Fixed it with additional dampening and lots of OC foam inside the doors. This fix lowered amplitude in the 1,2-2,2kHz area by 2-5dB overall (which were distortion).

You need the last beta version of RoomEQ to perform distortion measurements.

Sent from my Samsung Galaxy 3 via Tapatalk.


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## mooch91 (Apr 6, 2008)

Hanatsu said:


> It shouldn't sound that bad with the frequency response you got. I think you might actually have other issues.
> 
> Do a distortion measurement, I'm pretty sure you got issues there. Tuned a car recently, it measured fine but sounded harsh as crap. After a while I made a distortion test and found out that the system had like 4-5% tall order distortion products in the low midrange at reasonably low volume. Fixed it with additional dampening and lots of OC foam inside the doors. This fix lowered amplitude in the 1,2-2,2kHz area by 2-5dB overall (which were distortion).
> 
> ...


I'm thinking I'm also going to need a bit of a primer on how to do these properly and how to interpret... not much out there that I could find.

Seems like it uses the REW impulse measurement. Any particular bandwith? Full range? One speaker at a time?


----------



## mojozoom (Feb 11, 2012)

ooooh.... I did not know that REW had distortion measurements now. I'm glad you mentioned that as it'll simplify my testing today.

Thanks!

------

OK, I uploaded the beta and tried it out. Without the ability to overlay distortion plots it's really hard to judge differences between two tests. The 2nd, 3rd, 4th etc harmonics are nice though. It'd be interesting to see if those could provide clues as to what needs fixing.

For now though for distortion comparisons I'll have to stick with HolmImpulse as you can view three at a time. I'll email John and ask him to put distortion on the overlays if that's not already on his list.


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## Hanatsu (Nov 9, 2010)

mooch91 said:


> I'm thinking I'm also going to need a bit of a primer on how to do these properly and how to interpret... not much out there that I could find.
> 
> Seems like it uses the REW impulse measurement. Any particular bandwith? Full range? One speaker at a time?


Fullrange (20-20k), simple sweep. Measure the entire system first. If there's issues in that graph, measure each driver seperately and isolate the problem.

Sent from my Samsung Galaxy 3 via Tapatalk.


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## Hanatsu (Nov 9, 2010)

mojozoom said:


> ooooh.... I did not know that REW had distortion measurements now. I'm glad you mentioned that as it'll simplify my testing today.
> 
> Thanks!
> 
> ...


Yeah overlays would be great. IMD measurements would a cool feature as well, dunno how a IMD sweep works though. The ones I've seen are two-tone together with some spectrum analyzer.

Sent from my Samsung Galaxy 3 via Tapatalk.


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## mojozoom (Feb 11, 2012)

mooch, can you run a sweep in REW and show us the distortion and excess group delay as well?

Have you done sweeps yet in REW, with the laptop generating the sweep signal?


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## subwoofery (Nov 9, 2008)

mooch91 said:


> Kelvin,
> 
> So how should the two-way front stage sound without a sub? Right now my sub appears to be doing most of the midbass duty. When I run without it, the system can be very harsh. Very little midbass and the highs are piercing. Bring the sub back in to the mix and it doesn't sound "right", but it seems to calm the treble down.
> 
> When I was trying to get more midbass from the front stage previously, it seemed to really get muddy and distorted fast.


*IMPORTANT!!!!!*
1st thing to do is to save your current setting (EQ, T/A and Xover)

It might take a bit of time to get used to listenning to a system without subwoofers but it does sound like the sub is masking some problems. 
Where are your midbass crossed? Try to lower it down to 50Hz 24dB/oct just for tuning by ear (no need to listen to your system at ear bleeding level  - loud enough to at least hear a bit of midbass)

Piercing highs tells me you have a phase problem in the 4kHz-6.3kHz (maybe) - bring down 4kHz down to the minimum and listen to a well known dynamic track and bring back 4kHz until it sounds dynamic but not offensive. When doing that, listen to the midbass too, one click up or 2 clicks up and there's no midbass, 3rd click and midbass is there again <-- just an example  
Do the same for 5kHz and 6.3kHz 

When you're done, work on 8kHz and higher
After that work on 1kHz to 4kHz 

Based on your measurements, I'd leave the 1kHz range and below like this for now

Bring back your subwoofer and try to see if you need more of it or less - don't forget to bring your midbass HP up from 50Hz 24dB/oct

Kelvin 

PS: you might learn a thing or two in the process


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## mooch91 (Apr 6, 2008)

Hanatsu said:


> Fullrange (20-20k), simple sweep. Measure the entire system first. If there's issues in that graph, measure each driver seperately and isolate the problem.
> 
> Sent from my Samsung Galaxy 3 via Tapatalk.


Here it is (distortion measurement)... what's it mean?


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## mooch91 (Apr 6, 2008)

mojozoom said:


> mooch, can you run a sweep in REW and show us the distortion and excess group delay as well?
> 
> Have you done sweeps yet in REW, with the laptop generating the sweep signal?


And group delay with minimum and excess:


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## Hanatsu (Nov 9, 2010)

mooch91 said:


> Here it is (distortion measurement)... what's it mean?


Is this real SPL btw? I forgot to tell you that you need to test distortion at the volume you normally listen to music (or at least around 90dB average). 

This distortion plot shows harmonic components in the system. 

Example; let's say you play a tone at 100Hz, the speaker will create distortion (all speakers do). The 2nd order harmonic (measured in -dB or %) will be present at 100Hz*2=200Hz, the third order harmonic at 100Hz will be audible at 100Hz*3=300Hz. This distortion plot in RoomEQ displays all distortion components at all frequencies. 

The two peaks at 150-180Hz consist mainly of 2nd order HD, which mean they will be audible in the 300-360Hz area as a distortion. The fundamental SPL is ~95dB and the distortion peak is at ~57-58dB. 95-58=37dB relative SPL between fundamental and distortion components. -37dB = 1.41% harmonics present here.

That 1,41% will increase as SPL increases, I don't know at which SPL this was measured but if HD jumps above 3% other than in sub bass areas I'd be slightly worried. We're usually more sensitive to odd order harmonics (3rd,5th,7th etc...) than even order (2nd, 4th, 6th etc...) and the audibility increases as the order increases. The least audible and "best" distortion is therefore 2nd order. The "bad" ones are 3rd and 5th order, those are audible with lower percentage than 3% normally (of course, this depends on your hearing). 

The distortion plot looks good overall, IF this is done above 85dB at least. Try increase SPL by 10dB and see what happens... and this leads me to the next question;

The issues you been having, are they present at both low volume and high volume?

And btw, in the checkbox; remove THD and all distortion components above 5th order. Simply less mess in the plot


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## Hanatsu (Nov 9, 2010)

mooch91 said:


> And group delay with minimum and excess:


Uh, place some smoothing on that in the "All SPL" tab 1/12 is enough. And remove everything except excess phase in the checkbox 

And.... fix the scaling.

Top 150
Bottom -20
Left 20
Right 20000


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## mooch91 (Apr 6, 2008)

The spl should be close to accurate. It was a fairly loud sweep and I cal'ed SPL at some point.


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## Hanatsu (Nov 9, 2010)

mooch91 said:


> The spl should be close to accurate. It was a fairly loud sweep and I cal'ed SPL at some point.


Seems to be ok then. At this point someone really got to listen to the system to tell you what's wrong. We've run about every test there is now. Well except IMD, but that's a longshot really and cannot be measured in any easy way. Furthermore, systems with low odd order HD products are likely to have decent IMD performance.

Wish I lived closer to you, could probably have identified the issue if I heard it in person... =/


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## mooch91 (Apr 6, 2008)

Folks,

I'll post some of the cleaned up plots from the previous couple of threads tonight when I get home, just for completeness.

I did want to re-visit one of the thoughts that started this thread (even reflected in the title) which is the odd response of my subwoofer.

If you'll recall, I measured sub response like this, with 100, 80, and 60 Hz (approximately) 24 dB/oct crossovers:









Once I got the 3sixty, I sort of EQ'ed the sub and forgot about it while you guys helped me through some of the other EQ'ing.

I went back and noticed that I applied a -13 dB cut on the sub at 100 Hz with a Q=4 in order to get a resulting frequency response that resembled a 65/24 roll-off with a 65/24 crossover.

I re-measured EQ'ed and un-EQ'ed response from the sub last night and confirmed approximately the same result with REW and 1/24 smoothing.

Is it really possible for my sub response to _rise_ with increasing frequencies in this way or am I measuring something that just isn't real? Shouldn't a sub be rolling off as frequency increases?

I've just been wondering about this more because it's the oddest EQ filter I've had to apply across all of the speakers. 

Unless I totally flubbed the volume calc on my enclosure, I can't imagine what would cause this kind of response?

Perhaps something odd in my truck's transfer function that's not amplifying the lowest frequencies as expected?

Or am I measuring something that isn't real?


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## Hanatsu (Nov 9, 2010)

Can you measure the sub outside the car? Or at least measure with both doors wide open. Try that and see if the FR changes. I agree, it's a weird curve.

Sent from my Samsung Galaxy 3 via Tapatalk.


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## sqnut (Dec 24, 2009)

How does it sound now?


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## quality_sound (Dec 25, 2005)

My sub's response does the same thing. Peaks at 50Hz and rolls off on both sides. Moreso under 50Hz than above it.


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## ErinH (Feb 14, 2007)

Probably just constrictive correlation (modal bump). That or there is a null on each side. Most cars have a bump here. 

Something else to consider. Think about that bass thump you feel in your back At the seat. The mic will pick up vibrations. If you can feel it, odds are the mic will too and you'll get a response that indicates this. It could show up as a boost or a null depending on the phase relationship of the vibration the mic picks up vs the acoustic pressure at the electet. This is how accelerometers on speaker cabinets are used in conjunction with FR to determine detrimental effects from a resonating panel. 

The easiest way to see if this is a factor in your measurements is to decouple the mic. You can hold it in your hand at the headrest. However, this really only works for low frequency measurements but not so much for higher frequency measurements depending on where your hand is and it's influence on the results. 

Car audio is hard.


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## mooch91 (Apr 6, 2008)

sqnut said:


> How does it sound now?


Still not what I would expect from 800w and $2700.

I'm feeling like I'm making minor changes expecting it to suddenly come together and it never does.

I'm getting tiny gains here and there but none are making it "come alive".

Feel like I need the 'liveliness' first.

Sent from my mobile device.


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## mooch91 (Apr 6, 2008)

quality_sound said:


> My sub's response does the same thing. Peaks at 50Hz and rolls off on both sides. Moreso under 50Hz than above it.


The plot I showed is with LPFs active. Uncrossed it actually rises up towards 100 Hz.

Sent from my mobile device.


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## quality_sound (Dec 25, 2005)

I look at my plots again and see if it does that too.


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## mooch91 (Apr 6, 2008)

bikinpunk said:


> Something else to consider. Think about that bass thump you feel in your back At the seat. The mic will pick up vibrations. If you can feel it, odds are the mic will too and you'll get a response that indicates this. It could show up as a boost or a null depending on the phase relationship of the vibration the mic picks up vs the acoustic pressure at the electet. This is how accelerometers on speaker cabinets are used in conjunction with FR to determine detrimental effects from a resonating panel.
> 
> The easiest way to see if this is a factor in your measurements is to decouple the mic. You can hold it in your hand at the headrest. However, this really only works for low frequency measurements but not so much for higher frequency measurements depending on where your hand is and it's influence on the results.
> 
> Car audio is hard.


This has got me so intrigued. I've often wondered if I've been measuring things that aren't really there. Averaging, sweeping the mic, even holding it above the seat have all been things I've done to get reproducible measurements, but I've never been sure, still, if I've seen "phantom response" in my RTA measurements. And I don't know enough to completely correlate what I see vs. what I hear to know for sure. Figure I'm +20dB on my sub - could there be some resonance or vibration that's showing up on the frequency response plot as output?

Take my un-EQ'ed response for instance (*and in the attached, you can see the awkward roll-off on the sub I described previously - this is a 65/24 crossover folks*!). 









When I EQ this, I'm making huge cuts on the sub at 100 Hz (as noted previously, -13 dB or so with a Q=4) to get it to resemble a 65/24 roll-off.

I'm also taking huge chunks out of the left (green) and right (red). I have a -8dB cut at 100 Hz with a narrow Q (3 or 4) on the left and a -10 cut at about 150 with a wider Q (1.5 or 2) on the right to get it nearer to flat in this region.

What I end up with looks awesome, but is sounding like crap in the bass/midbass region (and is still sharp somewhere in the treble).










Maybe I'm over-sanitizing something that isn't really there?

Thoughts?

Dunno, maybe I'm grasping at straws...


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## quality_sound (Dec 25, 2005)

mooch91 said:


> this is a 65/24 crossover folks[/B]!).
> 
> 
> 
> ...


Look at the scale. That is ABSOLUTELY a 24dB roll-off. It just starts around 100Hz and like Erin was saying, you might be seeing something that isn't there below that. 

You're using a 6to8, correct?


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## mooch91 (Apr 6, 2008)

quality_sound said:


> Look at the scale. That is ABSOLUTELY a 24dB roll-off. It just starts around 100Hz and like Erin was saying, you might be seeing something that isn't there below that.
> 
> You're using a 6to8, correct?


3sixty.3...

Right, it's a 24 dB roll-off set at 65 Hz though. The crossover is doing it's job, but it's trying to roll off a rise in the response from 65Hz on up, which is why it doesn't look like a 65/24 roll-off.

This picture is an early shot of what my sub response looks like in-car with no LPF crossover and no EQ:


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## subwoofery (Nov 9, 2008)

What if you try a LP set to 40Hz 12dB/oct slope and play with phase a little? 

Kelvin


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## mojozoom (Feb 11, 2012)

I'd agree with that. It'd probably be worth trying to alter the LP to come up with a result that truly looks like a 24 db L-R slope.

Could we see a near field test of the sub, with the window gating pulled in as far as possible? If you can take the box out of the truck that'd be best, but shouldn't really be needed. 

I'll be that will be really interesting and maybe help us understand this a little more.


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## Hanatsu (Nov 9, 2010)

One question; does the plot you see on the RTA correlate with what you hear? Run a slow sine sweep across 20-150Hz on the sub, does it sound that peaky around 100Hz? (With EQ off)

Sent from my Samsung Galaxy 3 via Tapatalk.


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## mooch91 (Apr 6, 2008)

Hanatsu -
Excess GD, revised, as we were discussing in post #242.
Thanks.


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## mooch91 (Apr 6, 2008)

Hanatsu said:


> One question; does the plot you see on the RTA correlate with what you hear? Run a slow sine sweep across 20-150Hz on the sub, does it sound that peaky around 100Hz? (With EQ off)
> 
> Sent from my Samsung Galaxy 3 via Tapatalk.


With eq off and no crossover it sounds like it rises all the way to 200.

With eq off and a 65/24 crossover it sounds like it plateaus at 63 - 80 and starts falling off at 100.

In all cases there is a strong sound at 63 (resonance?).

These were observations made by standing near the sub with the back seat down, not in my normal seated/listening position.

I don't know how much of what I hear is representative of the freq response of the sub and how much is a function of the sensitivity of human hearing at those freqs though.


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## mooch91 (Apr 6, 2008)

Thinking out loud for a sec and trying to put together some of what you guys have been teaching me...

If I "hear" a very strong sound when playing a 63 Hz tone, but that frequency range doesn't show up as a standout on my FR plot, is it possible that I'm actually hearing something elsewhere in the frequency range than the frequency of the tone I'm playing? Meaning, that the 63 Hz tone is exciting some resonance at, say, 100 Hz that I'm seeing instead? Or some distortion harmonic?

Also, I take all of the overall FR measurements that I show by averaging pink noise over a 30 second period. For the low frequency measurements, should I be using gated/impulse measurements instead? Seems this method could overcome the potential described in the paragraph above?

But then I'm also thinking that any anomalies that I'm hearing are problematic, whether I'm measuring them or not. Anything that masks or distorts the true sound has to be an issue...


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## mojozoom (Feb 11, 2012)

The near field test on the sub may help answer that question. To run that test you have to bring the volume waaaaayyyy down as you have the mic about 2 inches from the driver, so there's not enough volume to excite resonances in the vehicle.

Regarding averaging, keep in mind that averaging does very little for you below about 1500 Hz, so if that's where we think the focus of the problem is then changing the averaging concept probably shouldn't effect anything.


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## Hanatsu (Nov 9, 2010)

mooch91 said:


> Hanatsu -
> Excess GD, revised, as we were discussing in post #242.
> Thanks.


Looks decent enough. The areas where the plot ain't flat you should avoid any EQ. You might get some amount of distortion otherwise. The peak at 200Hz correlates with the dip you have in FR for example. The range above 2kHz is a bit irregular, mine is flatter (if I had to guestimate...). Might have to move the tweeters to improve this. However it's a bit tricky to draw any conclusions. This plot will change as you move the mic and it will affect the high frequencies the most. No issues in the bass area according to this plot though.


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## Dillyyo (Feb 15, 2008)

mooch91 said:


> Guys,
> 
> I think it's time I take a short break from this effort... It's actually gotten a bit unhealthy for me, I think. I'm spending just about every waking minute behind the wheel, in the cold, trying to tune this system, and I feel like I just keep going in circles. I need a break. Plus, I think there are just too many anomalies that I need to investigate before I continue tuning.
> 
> ...



Mooch91-

Where in dirty jerzee do you live? I'm no golden ear, but I'd love to hear your system and see if I can add anything to the troubleshooting.


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## Dillyyo (Feb 15, 2008)

mooch91 said:


> Thanks guys. It will take me some time to process all of what you've commented to try a couple of things out.
> 
> A couple of other observations I wanted to make, not necessarily ones I've just realized in the past couple of weeks, but since I've started playing with this system.
> 
> ...


Unless the MP3 is of a putrid recording, you should not notice any significant difference between the MP3 or the loss-less form of the same MP3 i.e. CD, FLAC. Not saying you can't tell a difference if you really listen, but that drastic of a difference tells me you have hardware or setup issues.


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## mooch91 (Apr 6, 2008)

Dillyyo said:


> Mooch91-
> 
> Where in dirty jerzee do you live? I'm no golden ear, but I'd love to hear your system and see if I can add anything to the troubleshooting.


PM sent - appreciate any help I can get!


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## Woosey (Feb 2, 2011)

subwoofery said:


> What if you try a LP set to 40Hz 12dB/oct slope and play with phase a little?
> 
> Kelvin


I did this with 40Hz 6db/oct slope to reduce my sub's peaky behaviour... 

And all I can say is: nice....


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## Dillyyo (Feb 15, 2008)

mooch91 said:


> PM sent - appreciate any help I can get!


replied.


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## Hanatsu (Nov 9, 2010)

Seriously, is a rising sub response around 100Hz that common? In my experience I've rarely encountered it when tuning, when I think about it, of those ~30 setups I've installed I don't remember even one sub that peaked at 100Hz in this magnitude. Most subs I've installed/built tend to roll off naturally above 100Hz or so. I have basically a 15-20dB/oct natural roll off from the sub that begins around 150Hz, absolutely no peak around 100Hz, 20Hz is 15-20dB higher than 100Hz in my setup atm (without lowpass). Of course it depends on the car and setup, my car is relatively big. 

Is this common with small vehicles?Almost all installs I've done were in bigger cars.


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## sqnut (Dec 24, 2009)

mooch91 said:


> What I end up with looks awesome, but is sounding like crap in the bass/midbass region (and is still sharp somewhere in the treble).
> 
> 
> 
> ...


I think the basic problem is the virtual flatline on the response curve, from 125 hz up. Your current curve puts you in a particular soundscape and you're tweaking within that. For a minute, I want to take you out of your current sound and put you in a different soundscape. Tweak within this sound and see if it's better or worse than what you have now. 

Start by closing the underlap between sub and mids, if you still have it. Set both to 63 and put the sub on a 36 db slope (min), If the slopes on sub and mids are of different order, there will be phase issues, but nothing you can't correct with TA later. On your response curve see how the transition from sub to mid happens around 125hz? You need to pull that back towards 80ish for a start. 

I am going to set you up with basically an equal loudness response curve. This is how I set up all cars I tune. I'll set this broad curve and then fine tune within it. 

I aim for a 10-12 db roll off from about 40 to 160hz. Going by your curve above you have this covered. 200 to 250 will be a couple of db's lower than 160. The ears sensitivity picks up a bit in the 400-800 range so try setting this range 2-3db below the 200 range. You're losing the sensitivity gained in 400-800 over the 900-1.5khz range, so this range would be set at the same level as 200hz. 

The ear is most sensitive around the 3-5khz range. Set this range a full 8-10db lower. Aim for a 8-10db roll off from ~ 1.25 to 4 khz. If this range is not attenuated enough it will mask out the lower end where your ears are less sensitive.

The ears sensitivity starts falling over 5khz all the way till 10khz. But this range has a lot of issues like sibilance. This range would still be rolling off but at a shallower slope than the 1-4khz range. You can open up a bit at 10-12 for some additional dynamics and 'air' in the sound. I go for a steeper roll off after ~12 as too much of 14-16 can make the sound brittle and metallic. 

Try implementing this and see how it sounds. If the soundscape is better then we can work on tuning within this. Would be interesting to see some response curves with the revised settings. 

Arun


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## subwoofery (Nov 9, 2008)

Woosey said:


> I did this with 40Hz 6db/oct slope to reduce my sub's peaky behaviour...
> 
> And all I can say is: nice....


You just tried it? Where was your Xover before? You got more impact now? 

Kelvin


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## mooch91 (Apr 6, 2008)

Hanatsu said:


> Seriously, is a rising sub response around 100Hz that common? In my experience I've rarely encountered it when tuning, when I think about it, of those ~30 setups I've installed I don't remember even one sub that peaked at 100Hz in this magnitude. Most subs I've installed/built tend to roll off naturally above 100Hz or so. I have basically a 15-20dB/oct natural roll off from the sub that begins around 150Hz, absolutely no peak around 100Hz, 20Hz is 15-20dB higher than 100Hz in my setup atm (without lowpass). Of course it depends on the car and setup, my car is relatively big.
> 
> Is this common with small vehicles?Almost all installs I've done were in bigger cars.


I don't have enough experience to know, but it sure did look strange to me.

And I could characterize my truck as somewhat "big". It is a crew cab (full 4 door) pickup.


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## mooch91 (Apr 6, 2008)

sqnut said:


> Try implementing this and see how it sounds. If the soundscape is better then we can work on tuning within this. Would be interesting to see some response curves with the revised settings.
> 
> Arun


Worth a shot and I'll try it tomorrow.


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## Woosey (Feb 2, 2011)

subwoofery said:


> You just tried it? Where was your Xover before? You got more impact now?
> 
> Kelvin


Yup, last week I started this thread about passive highpass with a capacitor on a sub, long story short: it was a fluxcapacitor http://www.diymobileaudio.com/forum/technical-advanced-car-audio-discussion/146622-active-vs-passive-hp-sub-closed-enclosure.html

Then I rethought my situation and set the lp on the sub lower from 80hz 24db to 40hz 6db/oct which made the sub disappear and started to pound really nice for a 8" in a plusminus 10L closed enclosure.. hp is set on 25hz 18db to take out a lot of excursion.. My midbasses have the hp @ 125hz 6db/oct ( didn't adjust a thing for 3 days, no eq at all )

My car is a Mazda MX5 NB, with the sub in the passenger footwell..


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## Hanatsu (Nov 9, 2010)

mooch91 said:


> I don't have enough experience to know, but it sure did look strange to me.
> 
> And I could characterize my truck as somewhat "big". It is a crew cab (full 4 door) pickup.


Oh... thought it was 2 seater ^^

Still think you should measure the sub outside the car to see how the FR looks


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## Dillyyo (Feb 15, 2008)

Hanatsu said:


> Oh... thought it was 2 seater ^^
> 
> Still think you should measure the sub outside the car to see how the FR looks


I agree. With many of the problems occurring down in the lowest of octaves, seems it would be prudent to obtain the FR of the sub out of the car and subsequently, the transfer function of the vehicle.


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## Woosey (Feb 2, 2011)

Hey Mooch,

I was just looking at your buildlog and on the last page there's a pic of your enclosure..

Now I see the front and back panels are pretty large, could it be your enclosure resonates a lot without bracing in the inside? Maybe when stiffened it sounds more relaxed without enclosure resonance..

Just a thought.. 

If you still have the old enclosure you could try to close that port and try it with the bigger enclosure and see what it does?


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## subwoofery (Nov 9, 2008)

Woosey said:


> Yup, last week I started this thread about passive highpass with a capacitor on a sub, long story short: it was a fluxcapacitor http://www.diymobileaudio.com/forum/technical-advanced-car-audio-discussion/146622-active-vs-passive-hp-sub-closed-enclosure.html
> 
> Then I rethought my situation and set the lp on the sub lower from 80hz 24db to 40hz 6db/oct which made the sub disappear and started to pound really nice for a 8" in a plusminus 10L closed enclosure.. hp is set on 25hz 18db to take out a lot of excursion.. My midbasses have the hp @ 125hz 6db/oct ( didn't adjust a thing for 3 days, no eq at all )
> 
> My car is a Mazda MX5 NB, with the sub in the passenger footwell..


Shallow slope (6dB or 12dB/oct) works great when used with a subwoofer that is in an enclosure slightly on the small side. 
10L is what most 8" drivers need - but not having lots of energy below 30Hz (most of the time), it sounds much louder above 50Hz than below 30Hz. 
What you're then doing with a shallow slope is "flattening" the peak around 45Hz-60Hz (depending on the vehicle) which helps with subwoofer integration... 

Worked great with the underseat shallow 10" enclosure in my missies car 

Kelvin


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## mooch91 (Apr 6, 2008)

Some nearfield sub measurements. Or at least as nearfield as I could get. This is with sub propped up on the folded back seat, all doors open, mic about 2" away from the center of the cone, volume as low as I could get it. No crossover, no EQ, sweep from 20 -1000 Hz.

I got two different kinds of response, as you can see. I'm not entirely sure, but I believe this was a function of how steady I held the mic during the readings. The upper set was very steady, all the way through the impulse and subsequent calculation (through display of the spl graph in REW); the lower set was less steady, I believe. Does this sound right?


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## mooch91 (Apr 6, 2008)

I am 100% certain that I don't have my subwoofer/enclosure sufficiently stabilized or decoupled from the back wall of the truck. When I reinstalled, I fitted a quilted blanket beneath and behind the sub and I've got a whole different sound. It's probably exacerbated by the fact that my new enclosure is not carpeted, but Line-X'ed instead.


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## Woosey (Feb 2, 2011)

mooch91 said:


> I am 100% certain that I don't have my subwoofer/enclosure sufficiently stabilized or decoupled from the back wall of the truck. When I reinstalled, I fitted a quilted blanket beneath and behind the sub and I've got a whole different sound. It's probably exacerbated by the fact that my new enclosure is not carpeted, but Line-X'ed instead.


Is it possible to pop out the woofer and glue in some pieces of wood between front and back panel? ( an old broomstick serves good for this, saw off 2 pieces with the angle of your baffle and knok em in with a small hammer, so they kind of press the panels to the outside 1 left and 1 right of the woofer )

you could also carpet the bottom and back to see what happens... 

just another thought..


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## sqnut (Dec 24, 2009)

Did you try the equal loudness response curve?


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## mojozoom (Feb 11, 2012)

To me the nearfield plot of the sub appears to line up closely enough to the WINISD predicted curve where I wouldn't think there's anything fundamentally wrong with the sub or box itself.


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## Dillyyo (Feb 15, 2008)

mooch91 said:


> I am 100% certain that I don't have my subwoofer/enclosure sufficiently stabilized or decoupled from the back wall of the truck. When I reinstalled, I fitted a quilted blanket beneath and behind the sub and I've got a whole different sound. It's probably exacerbated by the fact that my new enclosure is not carpeted, but Line-X'ed instead.


I seriously doubt the preparation of your box is the cause of your sub response issues. Now, possibly shape and positioning, but I seriously doubt outside finish or whether it is securely stabilized. 

Question: when you made your box, did you take the measured transfer function of the vehicle into account?


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## mojozoom (Feb 11, 2012)

If it's exciting the rear wall of the cab though and that wall isn't deadened then it would make an impact. The rear of the cab is possibly acting as a diaphragm, turning the whole bloody thing into a speaker. 

If he heard that much difference with just a blanket around it, then it's a real issue. Probably not the only issue here, but at least it's one that's now been identified and that can be fixed.

So at this point it's worth deadening the heck out of the back wall of the cab, and securing the box so it can't go banging on the wall like a bass drum.

Again, I don't see any reason to jack with the design of the box itself. It works fine for the constraints that it had to work around.


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## Dillyyo (Feb 15, 2008)

mojozoom said:


> If it's exciting the rear wall of the cab though and that wall isn't deadened then it would make an impact. The rear of the cab is possibly acting as a diaphragm, turning the whole bloody thing into a speaker.
> 
> If he heard that much difference with just a blanket around it, then it's a real issue. Probably not the only issue here, but at least it's one that's now been identified and that can be fixed.
> 
> ...


I understand what you are saying, but I seriously doubt the sheet metal is that thin back there that the box could be exciting it without it emitting some irritating resonance that would have pointed to it over the past several years. 

In respects to the box, I didn't say that it needed to be changed, only that if there would be any concern it would be in the design of the box. I am not familiar with the flat subs that have come out over the years. I know they were designed to be used in shallow enclosures and small volumes, but I am not familiar with there in application characteristics and whether they tend to be peaky further up the FR than most normal subs. 

I'm meeting up with Mooch this week so hopefully I'll have a better idea of what he is dealing with. I honestly don't know how he made it 5 years with this type of issue.  I would have went nuts and crap would have been ripped out already and placed somewhere else.


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## mojozoom (Feb 11, 2012)

The Ford door skins are notably floppy, so I wouldn't expect other areas of the truck to be much different -

Drivers Door Skin / Panel "shakes" When Closing Door? - F150online Forums


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## Dillyyo (Feb 15, 2008)

mojozoom said:


> The Ford door skins are notably floppy, so I wouldn't expect other areas of the truck to be much different -
> 
> Drivers Door Skin / Panel "shakes" When Closing Door? - F150online Forums



You might have me there, as I have never owned an American car and substantiated as to why since my parents never owned anything but. LOL


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## mojozoom (Feb 11, 2012)

I've owned many, but the flimsiest was a 2001 Ford van. The roof rung like timpani every time you hit a significant bump in the road.


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## mooch91 (Apr 6, 2008)

Updates -

Didn't get too much time to play over the weekend, with other things to do. 

A number of folks have been looking at my REW plots behind the scenes and have observed some issues, particularly on the left side. Some significant cancellation and potential resonances in the midbass/midrange areas. I'll probably take my door panels off again at some point soon and see if I can make some improvements with more deadening. I'll also re-measure with REW once the door panels are off. I've always been concerned about the potential for my mids to contact the back of the door panel; my original set of speakers were the Alpine Type X REFs with the aluminum cones - and the cones split within a couple of years. I always chalked it up to overdriving them in some way, but I've always wondered if they could have been contacting something instead.

"Quilting" the sub didn't make as much difference as I initially thought. It may have stopped some panel resonances, but not to the point of a night and day difference. As a matter of fact, it's now pushing the sub up against the back seat which isn't good either at higher volumes...

I'm also trying some of sqnut's suggestions with EQ. I've set up one of my EQ presets to sort of match what he has described, just as something different to try. I've also got a preset that mojozoom crafted for me. 

Unfortunately still, I think whatever I'm dealing with goes well beyond what an EQ is going to fix at this point.


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## mooch91 (Apr 6, 2008)

Dillyyo said:


> I honestly don't know how he made it 5 years with this type of issue.  I would have went nuts and crap would have been ripped out already and placed somewhere else.


In fits of rage, I've been close to just going back to the stock pieces so many times...


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## sqnut (Dec 24, 2009)

mooch91 said:


> Unfortunately still, I think whatever I'm dealing with goes well beyond what an EQ is going to fix at this point.


I think the solution to your problem is finding the response curve that works for your vehicle and install. The cars environment and the odd speaker placements messes up the sound at your ear level. However, everything that goes wrong does so in either, the time or response domain. 

Your REW results show that arrival times are largely taken care of. That leaves your response curve and hence the solution lies in using the eq to dial it in. You could have minor install issues, but rest assured they would be minor. Point is you could spend a ton of time chasing down small tiny things to correct only to find little or no overall improvement.


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## ErinH (Feb 14, 2007)

Where do you live? Is there anyone in your area that can help you work through this? Someone you trust to have a good ear and experience? As an avid user of measurement gear and data to help analysis, I also understand it has shortcomings and limitations. Mostly in the way the user reads and applies the data. At some point you have to learn to listen and be able to discern by ear the issues. Then use the data to help you correlate those issues. Although, in the case of low frequency response, the data is MUCH harder to use in a way that provides fruitful results. Additionally, while measured TA may be spot on in impulse you have to also understand that TA is a means of altering the combing pattern. And altering the combing pattern alters the combined response you hear. No matter what I or anyone else says, a measurement system is limited by numerous things (mostly the human factor) and even when these are understood the likelihood of being able to discern and qualitatively realize advantageous tradeoffs from a sample set of data is a near impossible task especially when you know how important exact placement is to the measurement. We're talking less than centimeters being all the difference in the world in high frequency phase and magnitude response.


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## Dillyyo (Feb 15, 2008)

Mooch- Sent you a PM.


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## mooch91 (Apr 6, 2008)

Guys,

I've been a way for a few days, but rest assured I'm still working on my system! 

I had a chance to meet up with Dillyo over the weekend. He gave my system a critical listen and thought I really was in the ballpark from a tonality perspective. He picked up some things that he thought were just compromises for 6.5" mids and a shallow sub in a small sealed box.

The one thing he did challenge me on was the imaging and staging of my system. Having never heard a really good staging system, I wasn't sure what I was looking for in this regard. So I initially relied on some of the REW measurements which left me with a stage that was compressed to the right and dragged down significantly on the left. We used one of the EMMA room positioning tracks to hear this out. I reduced the delay on the left mid by about 0.4ms after he left and the stage just opened up. I still think I've got a bit of a "rainbow effect" on the left and right, with the extremes feeling a little bit pulled down, but it's a whole new experience to have the breadth of stage I have now. I've been testing some jazzier tracks which have a lot of extremes in the staging, and I've been mesmerized by the effect.

I also had a chance to listen to Dillyo's system, which is probably the first SQ reference I've heard in at least three years. I think it helped me break the psychological circle I've been running through, thinking I didn't have my setup dialed in perfect, therefore something must be wrong. His setup is definitely more capable and more dialed in than mine, but listening to it helped me to realize that I'm probably not that far off overall.

Since this time, I've made a few tweaks.

I left the sub at a 45 Hz crossover with a 48 db/oct slope. This seems to be the best way to deal with the peak at 100 Hz that I'm experiencing in-car, without resorting to a lot of EQ. Mids are crossed at 65/24.

I had a lot of cancellation with this crossover point (presumably a result of the difference in slopes between the sub and the mids), that I initially resolved by adding delay to the sub (3 ms). Instead, I recently flipped polarity on the sub which seems to have filled it in without needing any delay. Bass and midbass seems much better, but it could also be that my amp is working better now that it's warmed up (knock on wood, it hasn't cut out on me once in the past week or so!).

I've tried to emulate more of the frequency response that sqnut described in some posts from last week. I think I've still got a touch of harshness in the tweeters. Trumpets in the jazz I've been listening to have been screeching a bit - so I've been trying to lower the 2000 Hz region a bit more (am I in the right place?). I've also been boosting a little in the 8000-12000 region because the highs were sounding a bit on the flatter side.

I'd like to work a little more on the harshness and see what I can do about the staging "rainbow effect" without changing any of the installation. I'm not sure if tweaking tweeter polarity might help.

Anyway, I wanted to report that I've been enjoying the music a little bit more without obsessing over every bit of the sound quality. And I wanted to thank Dillyo for taking the time to help me out this past weekend.


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## sqnut (Dec 24, 2009)

Glad to hear about the progress. It always helps if you can get someone to listen and offer suggestions. Curious to see your current response curve with all drivers playing.


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## Dillyyo (Feb 15, 2008)

mooch91 said:


> Guys,
> 
> I've been a way for a few days, but rest assured I'm still working on my system!
> 
> ...


It was good to meet you to, bro. It's always good to get another persons perspective on things and I'm glad I could help a fellow brother out.


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## Hanatsu (Nov 9, 2010)

You should try changing polarity on tweets. In some cases it might raise the stage a little. Great that you found someone to listen at your system!

Sent from my Samsung Galaxy 3 via Tapatalk.


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## mojozoom (Feb 11, 2012)

mooch91 said:


> We used one of the EMMA room positioning tracks to hear this out.


This sounds like something worth trying - which EMMA disc were you using?


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## mooch91 (Apr 6, 2008)

mojozoom said:


> This sounds like something worth trying - which EMMA disc were you using?


I believe it was the 07 disc, but I'm sure my 09/10 disc also has the track that simulates room positions.


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## mooch91 (Apr 6, 2008)

Hey guys - me again. Listening more than tuning right now as I've tried to turn off the obsession for a while and enjoy the music instead.

Maybe you can entertain some questions on sub integration, where I'm still having a little bit of challenge.

I'm going to admit up front that I'm not completely sure of the differences between phase and time alignment, and I think they're both a factor in what I'm about to describe, but anyway...

I've been A/B listening with both normal and reverse polarity on my subwoofer. I know that with 24 db/oct slopes on both my sub and my mids, there is a measurable cancellation that occurs around the crossover point between the two when I'm running with reverse polarity.

Interesting thing is that neither gives me an 'ideal' bass/midbass sound, but the sound I get when I'm running reverse polarity is so much more satisfying. I don't know exactly how to describe it, but it's much deeper and more visceral than the sound I get with normal polarity. As a matter of fact, with the subwoofer connected with normal polarity, the sound is very constrained, and sounds soft. At times it can even sound mechanical in nature. And I find that the pressure created has been a bit uncomfortable to my ears.

The drawback with running reverse polarity is that the bass is localizable and less defined. Meaning, the pluck of a bass sounds deep and resonant, but it sounds more like it's "around me" as opposed to on the stage, and there's less definition in the pluck.

So can anyone help me translate these observations in to something useful? I think I've been trying to decide which polarity to compromise with, without really understanding what's going on. Why do I find the reverse polarity so satisfying if it's resulting in cancellation?

Is it anything more than the cancellation removing some of the dominant frequencies around the crossover point (meaning I could achieve the same result with EQ and normal polarity), or is there something more going on in the whole region?


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## mojozoom (Feb 11, 2012)

Sub integration is keyed around phase matching at the crossover point.

The difference between those two settings you're listening to really just boils down to 1/2 wavelength, which is about 7.5' if you're crossed around 65 Hz or so. By running the delay on the sub out from where you have it now to about 7.5' further out will do the exact same thing as the polarity swap, but you get to hear the difference that each increment makes, and you can pick what you like the best.


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## mooch91 (Apr 6, 2008)

Still here, still trying... anyone still out there?

I'm fairly satisfied with my ability to EQ and correct issues from about 300 Hz on up. I feel I understand the concepts of T/A to help with imaging and I feel good about the results I can achieve.

Still struggling with the low end...

I've been wanting more bass, I just haven't been satisfied with the quantity of what I've been tuning to. So I've tried a number of ways to raise the low end: raise the sub level, EQ the mids back up in the midbass range, lower the crossover and raise the sub level, steeper slopes and higher level on the sub, etc. 

What I've been finding is that all of the methods have about the same effect - they raise the bass level, but it just doesn't sound _right_. There's a strong bass _hit_, but it just doesn't resonate/reverb properly.

So I've been thinking more about the "envelope of sound" - the attack, sustain, and decay - of the bass. I've done some reading on the concepts and what I believe I have happening is a fairly realistic attack for bass sounds, but an unrealistic sustain and/or decay. I was paying close attention to my wife's Honda Pilot OEM stereo tonight and while it's all over the place in terms of overall frequency response, the bass notes are fairly satisfying - maybe a little too much decay - but this was the key difference I observed when comparing to my system. 

When I was describing the "satisfying" nature of the sound when reversing the phase of the sub, this is what I believe I was hearing - a more realistic attack and decay of the bass sounds. But reversing polarity came with the price of a significant loss of midbass.

For example, a mallet hitting a bass drum will have a realistic attack on my system - I will hear the hit fairly well, but the sustain is exaggerated - I get a pressurization (that actually bothers my ears at times) that seems to reverb for a while. And there is very little decay - the roll-off of the "boom" of the drum hit is almost non-existent. 

I get a similar effect for things like bass strings - very pronounced "pluck", but the decaying reverb following the pluck almost doesn't exist.

I have no idea why this is happening and I can't seem to resolve it with _any_ EQ changes (or because I'm just guessing at the EQ requirements to "fix" this, I'm making the wrong changes).

The other thoughts that keep coming to mind that could be causing this:
- My sub fires in to the rear seat. Could the cone/surround of the sub be contacting the seat, or the seat in some other way be interfering with the sound wave (backpressure?) that's impacting the decay? I know I've run with seat both up and down and never really sensed much difference.
- Cancellation/masking effects from engine noise. The diesel is a noisy beast - I was listening to test tones tonight and got some weird effects when playing 20/25/31 Hz tones with the windows open - resonances that were timed with the engine cackle.
- Too much/little of some frequency... The RTA plots show nothing unusual, but maybe there's something I'm hearing just not measuring. I get a fairly flat output down to 20 Hz, but maybe it's too strong down low?
- Something amiss in the signal chain... infrasonic filter stuck on inside the amp, for example.

Any other thoughts of what to look for or troubleshoot? Is now the time for more some impulse measurements of the sub?

Interesting thing is that I feel like I had a satisfying bass sound when I initially installed the JL sub (it's been a while, though, so I could be remembering wrong) and I haven't been able to achieve it since.


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## mojozoom (Feb 11, 2012)

I deadened my entire roof last week, and it was like I bought a new sub. Big smile.

Since the notes can decay off quicker, the abruptness of the next note is more noticable and the effect is sharper, harder hitting low end. I can drive more power to the sub and get more bass, not mushier mess.

The car is quieter also - gone is the poing-poing sound that I used to think was from the tires when I crossed a crack in the road at freeway speed. 

Just an idea - maybe the roof/doors or something else is a good target to try some addl deadening on.


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## mooch91 (Apr 6, 2008)

I guess I could be dealing with an exaggerated decay at one frequency that's masking the natural decay at others...

Too many variables!


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## mooch91 (Apr 6, 2008)

Starting to worry about my luck a little bit...

Started smelling a "band aid" type odor when I was playing my system this morning. Traced it down to the general area of the mid-woofer in both doors.

I haven't been hearing any distortion, but one of the things I've been trying to do is tone down my sub and drive the mids a little bit more in the transition region. Based upon the comments I had above, it seemed as if any attempt to drive up the sub was really causing the bass to sound funny.

Wondering if I was pushing them too hard, or they're on their way out...

Either I was heating up the voice coil or heating up wiring, one of the two I imagine.


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## Hanatsu (Nov 9, 2010)

Take your measurement mic and record some music in the car. See if we can hear somewhat how it sounds 

Sent from my Samsung Galaxy 3 via Tapatalk.


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## mooch91 (Apr 6, 2008)

Hanatsu said:


> Take your measurement mic and record some music in the car. See if we can hear somewhat how it sounds
> 
> Sent from my Samsung Galaxy 3 via Tapatalk.


Sarcasm I suppose?


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## sqnut (Dec 24, 2009)

Let's talk about the low end since that seems to be an issue for a few folks who are tweaking. For anything to sound right, you have to have the correct response across its fundamentals and harmonics. I think of this as good balance. A balance between how loud and how clear / lifelike. That's how I think of lower end fundamentals and their harmonics. 

For the percussion instruments to sound real, one needs a sense of balance between 80-300hz which gives you the power/loudness, 500-800 which are the lower end harmonics and 1-2khz which are the higher end harmonics. In your case you seem to have this balance tilted towards the loud/power end of the scale. Opening up the 1-2khz range should bring out better balance. 

One way is to leave 100-160hz where it is and just raise the 1-2khz range one frequency at a time. Let's say you would need to add X db in the 1-2khz range for better balance. You could also cut the 100-160hz bit and then try to raise 1-2khz (chances are you will need to raise less than X) and a touch at 500. 

The ringing sound / delayed decay that you are experiencing could be due to 100-125 hz and 600-800hz being a touch hot. When you have this do you notice a lack of vocal clarity? Like the vocals sound a bit muddy?


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## subwoofery (Nov 9, 2008)

sqnut said:


> Let's talk about the low end since that seems to be an issue for a few folks who are tweaking. For anything to sound right, you have to have the correct response across its fundamentals and harmonics. I think of this as good balance. A balance between how loud and how clear / lifelike. That's how I think of lower end fundamentals and their harmonics.
> 
> For the percussion instruments to sound real, one needs a sense of balance between 80-300hz which gives you the power/loudness, 500-800 which are the lower end harmonics and 1-2khz which are the higher end harmonics. In your case you seem to have this balance tilted towards the loud/power end of the scale. Opening up the 1-2khz range should bring out better balance.
> 
> ...


Reason why I suggested a few weeks ago that he tries to tune without the subwoofer... 

Kelvin


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## mooch91 (Apr 6, 2008)

subwoofery said:


> Reason why I suggested a few weeks ago that he tries to tune without the subwoofer...
> 
> Kelvin


I've been trying...


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## mooch91 (Apr 6, 2008)

sqnut said:


> Let's talk about the low end since that seems to be an issue for a few folks who are tweaking. For anything to sound right, you have to have the correct response across its fundamentals and harmonics. I think of this as good balance. A balance between how loud and how clear / lifelike. That's how I think of lower end fundamentals and their harmonics.
> 
> For the percussion instruments to sound real, one needs a sense of balance between 80-300hz which gives you the power/loudness, 500-800 which are the lower end harmonics and 1-2khz which are the higher end harmonics. In your case you seem to have this balance tilted towards the loud/power end of the scale. Opening up the 1-2khz range should bring out better balance.
> 
> ...


Seems things get a bit thinner when I open up the 1-2k range (I've actually been toning down 2k+ from some of the feedback here, and experience that tells me that my sound was too harsh). Could I maybe already have too _much_ here?

How about in the 100 - 500 Hz range? I've been noticing that raising anything from 100 on down causes the dead bass sound I described. This is why raising the sub has been problematic and the tail on the sub at 100 Hz has also been an issue. But when I give a little boost from 200 on up to about 500, I get a little bit more natural percussion sound. Not perfect, but definitely a little better.

I've also been noticing when measuring my home system that I have a shallow downward slope from about 40 Hz to 500, which is where it levels off.

Maybe my upper midbass/lower midrange is a little out of whack? The unfortunate thing is that boosting EQ in this range, especially around 200 Hz (where I get that significant null when playing L+R together), starts to get a little distorted sounding.


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## subwoofery (Nov 9, 2008)

mooch91 said:


> I've been trying...


Try HARDER 

What happens when you lower 125Hz (-3dB) , 160Hz (-3dB)? 

What about 200Hz (-2dB)? What's happening to the sound? 

Kelvin


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## sqnut (Dec 24, 2009)

Yeah, try cutting some in the 160-300hz range, without touching the 1-2khz range. Also cut some at 80hz. See if that cleans things up. I'd cut 100-125 last.


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## Brian Steele (Jun 1, 2007)

Getting a subwoofer to integrate best with the rest of your system requires choosing not only the optimum x-over points, but also using time alignment. 

For example, right now I'm using 80 Hz 12dB/oct on my midbass speakers and 125 Hz 12dB/oct on the subs. Without any time alignment, this arrangement would produce either a big dip in response below 100 Hz or so, or a dip in the midbass response (depending on if I had the subwoofer running normal or reverse phase). However, once I dialled in the time alignment correctly, I was able to get rid of the midbass dip. I'm quite happy with the results, though I do plan to play with the config a bit more and document the changes.


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## sqnut (Dec 24, 2009)

mooch91 said:


> Seems things get a bit thinner when I open up the 1-2k range (I've actually been toning down 2k+ from some of the feedback here, and experience that tells me that my sound was too harsh). Could I maybe already have too _much_ here?
> 
> How about in the 100 - 500 Hz range? I've been noticing that raising anything from 100 on down causes the dead bass sound I described. This is why raising the sub has been problematic and the tail on the sub at 100 Hz has also been an issue. But when I give a little boost from 200 on up to about 500, I get a little bit more natural percussion sound. Not perfect, but definitely a little better.
> 
> ...


One way to open up the 1-2khz range a bit, is by cutting deeper in the 600-800 range. If the balance is out cause the lower end is fatter than it should be, 160-300hz is where I would look at first. 160 on it's own can make the sound too fat or too thin and 200-300 just add unwanted boom to the sound. Once you're done cutting this range, revisit 500-800 and the 1-2, you may need to cut here. I'd cut at 80hz if you want to reduce foundation size for your MB.

If you're working on your MB, then go with what Kelvin is suggesting and switch off the sub for a bit. The thing about your sub is that you hardly ever hear it, unless you listen to stuff like dub, trance etc. With most music ~70hz is about the lowest. Which means that you should be hearing ~90% of your low end from the mids. Hence when you turn the sub off you should not feel a sense of major loss and it will help you set up the MB a bit easier. I will cut the sub while working on the MB and by the end of tuning forget that I turned the sub off. Later when a song hits a note I'll realise that the sub is off.


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## mooch91 (Apr 6, 2008)

sqnut said:


> Let's talk about the low end since that seems to be an issue for a few folks who are tweaking. For anything to sound right, you have to have the correct response across its fundamentals and harmonics. I think of this as good balance. A balance between how loud and how clear / lifelike. That's how I think of lower end fundamentals and their harmonics.


So, I've been trying for more _balance_. 

Last couple of days, I've been resisting "turning up the sub" to get more bass. I actually spent some time with the sub off and realized my 6.5s were delivering very little midbass to the overall sound. I adjusted and flattened out the mids in the 60-200 Hz region (they still don't play much lower than 80-100 and they cancel severely right at 200 when playing together, but I made some tweaks here since this was an area I was just avoiding previously). I pulled a lot of energy at 100 - 125 Hz out of the sub as well (this helps keep my true crossover point lower as well).

When I brought them all back together, I kept the sub relatively low in level compared to before as well.

The result is positive so far. Not quite enough impact, but better balance for sure. Decent dynamics, and the bass line in the music I've been listening to is distinguishable. 

I may go back and revisit the deadening in my doors. I'm thinking I may be leaving some output on the table in the region I've been adjusting. Plus I think I'm catching some resonant sounds now that I'm asking more of the mids.

What's been particularly hard about "tuning with the sub off" is that I really don't know how much impact and low end I should expect without it running. Keeping it in the mix while tuning gives me the immediate satisfaction of the impact I'm looking for, but it's probably also left me quite out of balance across the drivers.


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## mooch91 (Apr 6, 2008)

Brian Steele said:


> Getting a subwoofer to integrate best with the rest of your system requires choosing not only the optimum x-over points, but also using time alignment.
> 
> For example, right now I'm using 80 Hz 12dB/oct on my midbass speakers and 125 Hz 12dB/oct on the subs. Without any time alignment, this arrangement would produce either a big dip in response below 100 Hz or so, or a dip in the midbass response (depending on if I had the subwoofer running normal or reverse phase). However, once I dialled in the time alignment correctly, I was able to get rid of the midbass dip. I'm quite happy with the results, though I do plan to play with the config a bit more and document the changes.


I'll re-check T/A now that I'm in a different place with EQ, but every time I've measured low-end output around the crossover point with various time alignments (see "rainbow plots" discussions earlier in this thread), I always get max/smoothest output when time alignment on the sub vs. mids set to 0.


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## sqnut (Dec 24, 2009)

mooch91 said:


> I actually spent some time with the sub off and realized my 6.5s were delivering very little midbass to the overall sound.


Hence your desire to turn the sub up. While tuning you will want to listen to and tune one set of drivers at a time. Only mids, only tweets, mids and tweets on one side etc. This would be a good time to go fully active in case you have not.



mooch91 said:


> I pulled a lot of energy at 100 - 125 Hz out of the sub as well (this helps keep my true crossover point lower as well).


The reason why you were struggling with the 80-100+ range is because the sub was carrying this range i/o the mids. Typically, keep 70hz+ as mid territory and below that as sub territory. To achieve this I cross my mid and sub at 50hz, with the sub on a 36 db slope and then on the sub eq at the bit10, I will cut 80hz and above by a full 12db. I need to cut the sub at 50hz so that the mids can take over by 80. Most mids (mine included) are lame below ~70hz. I cross the mids at 50 cause I don't like to underlap or overlap at the lower end. 



mooch91 said:


> Plus I think I'm catching some resonant sounds now that I'm asking more of the mids.


One way to cure rattles is to use more deadening and the other way is to isolate the mid from the door. My mids are mounted on dual 3/4" mdf rings with a layer of dynamat between them. I had to cut the door panel to achieve this. Not the best solution from a resale point of view. But yeah try and see if you can isolate better. 



mooch91 said:


> What's been particularly hard about "tuning with the sub off" is that I really don't know how much impact and low end I should expect without it running. Keeping it in the mix while tuning gives me the immediate satisfaction of the impact I'm looking for, but it's probably also left me quite out of balance across the drivers.


Tune so that 70hz and above is from the mids, that's about 90% of the low end. While tuning the mids get them as deep and punchy as you can without using the eq below ~80hz. Then kick in the sub so that its playing that 50-70hz range. Set the sub level to blend it in and do some fine tuning in the 50-70hz if required.


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## therapture (Jan 31, 2013)

quality_sound said:


> Do you have any *Michael Jackson* or Dire Straights? You'll know pretty quickly if it's missing.
> 
> I'm glad you're making progress.


Interesting, MJ sounds GREAT in my car. Beth Hart as well. 

I have been following this thread, lurking, as me and mooch seem to be in the same boat, learning to EQ with a dsp and REW. I have been to timbuktu and back with the EQ. FINALLY, I am getting somewhere, partly from some of my threads, and some from here. 

I tried some housecurves, specifically the JBL/Andy and both of hanatsu's versiond...oh god...they sounded like ass in my car (NOT a reflection on the curves themselves, mostly on my tuning methods initially). I used hanatsu's baseline #2 as a model, and then started modifying it for the ranges I felt lacking. Last night, I finally hit some paydirt, and now I am actually fine tuning instead of starting over and over and over....LoL. When, and only at that point, I get to say, 90% happy with the curve...will I measure the system again. 

One thing that surprises me still, is that the TA settings can be so different from one tune to the other. Phase differences due to x-over and gain settings, as well as the frequency itself that is being changed?

I model my mids from 50-20,000, and I listen to them alot with no sub. My opinion is that, they should sound GOOD with no sub at all. They should have some bass, and some solid impact. When I get them to that stage, they blend SO much better with my sub, and I find I can cross the sub lower as per sqnut's method.


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## Oliver (Jun 25, 2007)

Deadening the doors is a good idea, are you aware of pseudo-bass or false bass?

Sometimes the reverberations from door mounted speakers make an issue of certain frequencies.


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## sqnut (Dec 24, 2009)

therapture said:


> Beth Hart as well.


Truly gifted, love her voice. Not sure why she isn't bigger and more popular.


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## mooch91 (Apr 6, 2008)

I'm afraid to change the disc I've been listening to. Things sound so good right now and I'm afraid its going to just fall apart with a different source.  

Sent from my mobile device.


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## sqnut (Dec 24, 2009)

mooch91 said:


> I'm afraid to change the disc I've been listening to. Things sound so good right now and I'm afraid its going to just fall apart with a different source.
> 
> Sent from my mobile device.


As long as the next cd is decently recorded, the wow factor will remain. Stay away from the 'digitally remastered' ones


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## sqnut (Dec 24, 2009)

Take the cd that was giving you the wow factor and listen to it on your home 2ch or whatever you're using as your reference point. So while the quality has gone up a few notches in the car, try picking the areas where it still lags the ref setup. Are you fully active or do you still have a passive between the mids and tweets?

Edit : P.S. Somewhere back in the thread you were wondering if the pio mids were any good with MB, no issues now, right?


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## mooch91 (Apr 6, 2008)

sqnut said:


> Take the cd that was giving you the wow factor and listen to it on your home 2ch or whatever you're using as your reference point. So while the quality has gone up a few notches in the car, try picking the areas where it still lags the ref setup. Are you fully active or do you still have a passive between the mids and tweets?
> 
> Edit : P.S. Somewhere back in the thread you were wondering if the pio mids were any good with MB, no issues now, right?


Still passive.

Yes, definitely more impressed with the Pioneers.


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## mooch91 (Apr 6, 2008)

Folks,

Here's where I'm at right now.

Overall system response:









And the approximate indepenent responses of the sub and the fronts:









You'll see I'm asking a lot more of the mids and a lot less of the sub than I had been. My "true" crossover is right about at 87 Hz.

The concept of balance has definitely made a world of difference.

I feel like there's just a little bit too much of something, and a little not enough of something else, but I'm going to listen to it for a while and enjoy it before tweaking any further.


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## sqnut (Dec 24, 2009)

I like the fact that you'll work on one thing and then spend time soaking in the change. That's the right way to go about it. Sometimes I'll be trying to do 50 things at a time and get all over the place without really getting anywhere. Knowing when to stop is important. 

Once you have the sense of balance, the idea is to build on it. Whatever is audibly less or more, is taking away from the overall balance. Let your ears pick whats excess and what is lacking and therefore, how it sounds. Easier to correct it that way. 

When you work on a particular issue, try and work in narrow bands. You don't want to upset the overall balance by correcting over a wide band. So if you're correcting for vocals, cut 200-300hz if the vocals are shouty. Add a bit in the 300-400hz range if the vocals sound hollow. Add at 600-800hz if the vocals are submerged and lost in the instruments. Cut this range if the vocals sound harsh. Too much energy in the 1-1.6 or 3-4khz will add to the harshness. 

Sometimes two bands can be related / work together. Eg 600-800hz and 6-8khz. Try and make cuts in both ranges, then leave one and cut the other. See how the vocals can go from dull and submerged to harsh and sibilant. Find the right balance. Next try the 1-2khz and the 3-4khz range.


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## Patrick Bateman (Sep 11, 2006)

james2266 said:


> I have almost the exact same curve problems as this actually. What vehicle is this anyway? Not a Rav4 by chance?  Anyways, a little experiment for you that I tried that told me this was a nasty room mode that ran the entire width of the cabin right smack where the front passengers sit. Try taking readings from the back seat or anywhere else really. Back seat was just easy for me. If the dip at 60 Hz goes away then it is likely a room mode. I am told you can do two things for a room mode, move the sub and/or midbasses or add more drivers. I am trying to conquer my problem with a larger midbass that should be able to better play these frequencies. I am getting them put in this evening so we'll see if the plan works or not.


Yep.

Due to the fact that the width of most cars is pretty close to a multiple of the length, you get a really nasty peak and a dip.

The tricky one is the dip. Here's why:

When you have two waves that are in phase, the waves will add constructively, and you'll get another six decibels.

But when they're OUT OF PHASE, you get a null. That's why the dip in the car is so maddening to deal with; basically acoustic nulls screw up your response a lot faster than peaks do, and it's a lot easier to fix a peak than to fix a dip. (Because nulls are so much deeper than the peaks are tall, due to the way that sound waves interact.)


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## Patrick Bateman (Sep 11, 2006)

mooch91 said:


> Folks,
> 
> Here's where I'm at right now.
> 
> ...


Here's something you might try:

If possible, try using a shallower slope, and cross it over higher. If it's an option, consider using six dB slopes. If that isn't an option on your head unit, you can 'fake' a shallow slope by using a steep slope, and then using EQ to tweak the rolloff. (For instance, setting the slope to 12dB per octave at 80hz, then using a 'cut' at 80hz to change the rolloff. Or a boost at 40hz. Either will work.)

Now the reason that the shallow rolloff might improve things is that it mimics the use of multiple subs. You're basically making your midbasses cover a lot of the range that your subs normally cover. And IMHO, multiple drivers playing in the two octaves from 40 to 160hz can really improve how 'natural' the bass sounds.

Check out these threads for more info:

Multiple Small Subs - Geddes Approach - diyAudio

http://www.diymobileaudio.com/forum...-discussion/144111-up-front-bass-new-way.html

A lot of subs are good to 500hz these days; the idea that your sub has to be crossed over at 80hz is a bit antiquated imho. And it might be counter-intuitive, but overlapping your subs and your midbasses can actually move the stage forward. You would think that you'd want to have your sub crossed over low to get the stage up front, but this isn't necessarily the case. The reason is because of the length of the sound waves. 150hz is seven and a half feet long, and due to that length, we can't easily perceive where it's coming from. So when both your sub and your midbass are playing midbass, we can't tell where the sound is actually coming from; it's so long. *Most of the things that 'give away' the location of the sub are higher in frequency. Such as a sub that's rattling the trunk. Or second and third harmonic distortion, which can happen as high as 250 or even 500hz.*


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## quality_sound (Dec 25, 2005)

I've had the best luck in my Golf with the sub playing up to 150Hz and then I can cross the mids anywhere from 40-150Hz. It gives me enormous flexibility.


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## sqnut (Dec 24, 2009)

I could never run a high xover on the sub _and_ get the overall sound to be accurate.


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## quality_sound (Dec 25, 2005)

It really depends on the sub, IME. Typically, lower Q subs tend to work better.


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## sqnut (Dec 24, 2009)

One of the issue I have with a high xover on sub has little to do with the Q on the sub.

Let's say you are running the sub to 150 hz on a shallow 12 db slope. Safe to assume that the 12" driver is louder than your 6.5" up to ~ 500hz. Hence your auditory cues for the 70-500hz range are 80% from the subs and 20% from the mids (appx average across the range). The sub is doing this range in mono and the mids in stereo. The two sound different. You are hearing a hybrid which is yet a third sound. Hence less accurate vis a viz what is recorded. No amt of eq/ta will cure this.

PA systems will use 12-15" as MB drivers, but consider for a second the difference between volume of air in a tin can and what is virtually an infinite volume. The only reason you need a sub in the car is cause your 6.5" mid won't get loud and visceral in the 30-70 hz range. For the [edit] range ~70-4 khz, the 6.5" are more than enough for loud and lifelike, based on physical dimensions and volume of air. Beyond 4 ish the mids start tailing off and you need a tweeter. [edit]


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## Woosey (Feb 2, 2011)

Mooch, 

How is everything sounding now? Satisfied? Or still struggling?


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## mooch91 (Apr 6, 2008)

Woosey said:


> Mooch,
> 
> How is everything sounding now? Satisfied? Or still struggling?


Still struggling... I thought I was doing better with it until this past weekend. My dad stopped by with his new Ford Edge (with the Sony system) and I thought it sounded a lot better than my system. More impact all the way around and there was absolutely no harshness to the vocals. It sounded a little dull at the top end, but all in all a stinkin' stock system once again sounded fuller and more dynamic than mine.

Female vocals, guitar solos, and trumpets have just been piercing on my system and I can't seem to tune them down. I've tried dropping the whole 2K - 8K range by 4 - 5 dB (and that's with the tweeters already set at the -6 dB point on the crossover) and I haven't been able to tame them. I can't find any particular frequency out of whack and the RTA isn't showing anything from 1.5K on up that's peaking. 

Sigh...


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## Hanatsu (Nov 9, 2010)

Try measure around the ears while sitting in the car. 4 points around each side and average them. Harshness is often in the 2-4kHz area.


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## sqnut (Dec 24, 2009)

If cutting the 2-4 khz range is not helping, then try cutting the 600-800hz range. If 600-800 is hot, it can add to harshness.


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## mooch91 (Apr 6, 2008)

In response to sqnuts note immediately above:

Did a little experimenting with the peq in my deck today. Dropped 500 by -4 with a Q of 1. Much more bearable and less fatiguing. 500 - 1650 is an area I've never touched because its has always stayed relatively flat.

I've also made some observations through comparisons to measurements of my 'reference' systems. I'll post some graphs later - they may prove insightful about some errors in my measurement methods or my target curve preferences.

Observations are mainly about the same midrange region noted above.

Sent from my mobile device.


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## therapture (Jan 31, 2013)

mooch, I had horrible results with some of the curves...what I did was play with REW and the housecurves, setting points in the curve file and then loading them into REW and seeing what the resulting curve looked like, and then adjusting the bands where I was too loud, too harsh, etc., until I had a smooth curve. I worked hard on level balancing after REW made a curve, using test tracks from several cd's such as the IASCA discs and the Autosound 2000 series.

Then I worked on the ranges that were "wrong" to get the tonal balance "right". For instance, I had a very sharp "ssssss" sound even after level balancing, so I added a band to my EQ with a Q of 3 at 7150hz, and cut both sides down the same amount until the tone was nice and crisp.

My own home grown curve looks flat from 125hz on basically (instead of tapering towards the high end), and it sounds fantastic. If I run the curves that steadily drop from the low frequencies (like the JBL housecurve) down to 20k, it sounds flat, dead, boring, and muffled. Each car is drastically different, and the same curve will sound great in one and like ass in another.

I say make your own curve and don't try to chase a curve someone else came up with, especially if it sounds like butthole. Make it personal, if you are not competing. Save what you got so you can revert to it.


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## Hanatsu (Nov 9, 2010)

You guys have weird acoustics in your cars ;P

My system sounds "flat" with a ~20dB tilt from 20-20kHz. Couldn't for my life listen to a "measured flat" curve, waaay too bright 

Sent from my Samsung Galaxy 3 via Tapatalk.


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## therapture (Jan 31, 2013)

Hanatsu said:


> You guys have weird acoustics in your cars ;P
> 
> My system sounds "flat" with a ~20dB tilt from 20-20kHz. Couldn't for my life listen to a "measured flat" curve, waaay too bright
> 
> Sent from my Samsung Galaxy 3 via Tapatalk.


I still have not measured the system tune, been busy running and not much time free. I have no idea what it really is but I am liking my sound.

I am feasting on midbass right now and I am probably overdriving that range.


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## Brian Steele (Jun 1, 2007)

sqnut said:


> One of the issue I have with a high xover on sub has little to do with the Q on the sub.
> 
> Let's say you are running the sub to 150 hz on a shallow 12 db slope. Safe to assume that the 12" driver is louder than your 6.5" up to ~ 500hz. Hence your auditory cues for the 70-500hz range are 80% from the subs and 20% from the mids (appx average across the range). The sub is doing this range in mono and the mids in stereo. The two sound different. You are hearing a hybrid which is yet a third sound. Hence less accurate vis a viz what is recorded. No amt of eq/ta will cure this.


Our ability to hear things in "stereo" starts to disappear below 200 Hz anyway, particularly when you're listening to music instead of pure tones. The traditional "80Hz" setting for subs is really based on what the resulting output would be at 200 Hz if an 80 Hz LP filter is applied. So, use a steeper filter, and you can use a higher filter frequency. 

Then there's the issue of cabin gain, which is going to add a whole lot more output below 80 Hz than it does above. Then there's the HF rolloff that will occur if the subwoofer is located in the trunk and your car is a sedan. The net effect of both being that the effective rollof is going to be lower, maybe even a lot lower, than the frequency the LP filter is set to.


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## sqnut (Dec 24, 2009)

Brian Steele said:


> Our ability to hear things in "stereo" starts to disappear below 200 Hz anyway, particularly when you're listening to music instead of pure tones.


This one of the many theoretical thingys that may not pan out in the real world. Here's a simple experiment. If you have separate L/R eq pick 125hz and boost one side and listen then cut what you boosted and boost the other side. Do you hear and feel the weight of bass shifting from one side to the other? I agree that our ability to hear in stereo tails off below ~ 100hz.



Brian Steele said:


> The traditional "80Hz" setting for subs is really based on what the resulting output would be at 200 Hz if an 80 Hz LP filter is applied. ...... maybe even a lot lower, than the frequency the LP filter is set to.


Based on my response above, I'm looking for the 80-90hz range for the mids to take over from the sub. Music is mostly mono below ~100hz, so the sub can do that range. That is why my xover point between sub/mid tend to be in 50-63hz range on steep slopes. No overlap or underlap.


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## sqnut (Dec 24, 2009)

therapture said:


> My own home grown curve looks flat from 125hz on basically (instead of tapering towards the high end), and it sounds fantastic..... Each car is drastically different, and the same curve will sound great in one and like ass in another.


Cars are different yes, but at a base level they are all small, highly reflective and near field environments with off set seating. They are similar enough that a 'flat response' from 125 hz - 20 khz, will sound thin and bright. Then boosting the sub to get more of the lower end, will give you the *boom boom* + *chick chick* sound. 

The curve that keeps 30-40hz 10 db higher than ~ 160hz and then flat from 160-1khz and then a 10+ db roll off to 20khz, is _*only a starting point*_ and not the desired end result. So if you plug this curve into your REW or whatever and expect spectacular results, you're setting yourself up for disappointment. If it were that simple, all cars would come with competition grade sound. Fact is it isn't that simple.

Once you have the base cure then you have to let your ears take over to tell you whats right and what isn't. 

- sounds flat? try boosting a bit in the 1-2khz range
- Vocals are muffled? Try boosting a bit at 500-800hz
- Lower end is boomy? Try cutting at 80/200-300
- is 160hz done right? too much here and the sound will be boomy, too little and the sound is paper thin
- Need a fatter punchier mid bass? Try raising a bit at 100-125 *and/or* cutting some above 12khz

The basic house curve is your starting point, once you get there then you tweak for your individual cars environment / install etc etc.


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## therapture (Jan 31, 2013)

sqnut, I definitely do not have the boom+chick syndrome, I hate that crap. My vocals are warm and inviting (think Beth Hart) but crisp and detailed as well. For whatever reason, the base JBL curve and Hanatsu's rev.#2 were just...muffled sounding, with practically no high end detail...guitar was flat and dull...kick drum the same way, no "punch". I just took the general low end and midbass response of those curves, and started working on the mid to high end, by ear, until I got it sounding good tonally, using a wide variety of music. It didn't take huge EQ swings to get there either. Your tips on how to cure the sound tonally is exactly what I was doing by ear. Being that I have 20 years of singing behind me, I decided to trust my ears a bit more.

I do not think my system response is flat at all, I think I will find the resulting actual "ear curve" will be drastically different than what I thought. The only way to now is for me to measure it, and I will have some free time tomorrow to get it done properly. 

Now when I make my Imagines into components (maybe tomorrow as well), I might find I will be extremely bright. I am pretty sure my door grill blocks alot more than I think, plus my left leg is adding a bad reflection that pulls the image left and makes the left driver become localizable. I am tired of having to try and keep my left leg out of the way, I am tall at 6'3" and I simply have very little space.

I have been following this thread as mooch and I seem to have had some of the same issues early on. Most of mine have been cured it seems with help from all of you guys. Low end is lively and articulate, drums pan very well, all the snap is there for midbass, vocals are happy, guitar is nice, piano as well, and the tweets are happy (as long as I keep my left leg out of the way).

I am on my 5th revision of my initial curve, I listened to each for several days, so I didn't make "knee jerk" changes.


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## sqnut (Dec 24, 2009)

mooch91 said:


> In response to sqnuts note immediately above:
> 
> Did a little experimenting with the peq in my deck today. Dropped 500 by -4 with a Q of 1. Much more bearable and less fatiguing. 500 - 1650 is an area I've never touched because its has always stayed relatively flat.
> 
> ...


Instead of making a deep cut at 500, try cutting 500 by -2 on a Q of 1, cut 630 by -3 on a Q of 2 and then cut 1.6khz by 2 on a Q of 1. Try this and see how it sounds. both 600 and 1.6 can add a lot of harshness to the sound. Too much of 500 will give a honky sound, too little and the vocals be dull and blurred. 800-1.25 khz are good for bringing out dynamics. 

Some observations:

1. Keeping your 500-1650 range flat. Ideally the roll off should start around 1 kz tops. With your passive setup the roll off will have to be lower. I'll explain that in the next post. Also, the further out you start your roll off, the steeper the slope. There has to be a minimum level of attenuation between this range and the 2.5-5khz range (about 5-7 db for a start). 5-20 khz will be another 4-5khz lower. That's the kind of roll off you want past 1khz. This is a starting point, you will need to fine tune based on what you hear. 

2. Running a range flat allows for a few instances of +/- 3-4db at 1/3 octave levels. Think in those terms. If you need to cut something in a flatish range because it clears up the sound so be it. 

3. Remember balance? If you sorta had balance and you wound up cutting 2-4khz by 4db without touching the 500-1650 range, what would that do to the overall balance? When you make a deep cut over an octave or more, you will need to cut other ranges as well to keep the balance. 

I'll mention a couple of other points in the next post. But before I go there, I'm curious about what is holding you back from going fully active . Fully active is a huge jump when it comes to tweaking.


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## sqnut (Dec 24, 2009)

therapture said:


> I do not think my system response is flat at all, I think I will find the resulting actual "ear curve" will be drastically different than what I thought.


If the sound is good the curve won't be flat. My post was more a reaction to your claiming good sound on the back of a flat response. A bit OTT cause you were a bit vehement in claiming good sound on the back of a flat response. 




therapture said:


> I have been following this thread as mooch and I seem to have had some of the same issues early on. Most of mine have been cured it seems with help from all of you guys. Low end is lively and articulate, drums pan very well, all the snap is there for midbass, vocals are happy, guitar is nice, piano as well, and the tweets are happy (as long as I keep my left leg out of the way).
> 
> I am on my 5th revision of my initial curve, I listened to each for several days, so I didn't make "knee jerk" changes.


All good.


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## therapture (Jan 31, 2013)

sqnut said:


> If the sound is good the curve won't be flat. My post was more a reaction to your claiming good sound on the back of a flat response. A bit OTT cause you were a bit vehement in claiming good sound on the back of a flat response.


I think the only thing flat is the graph of my curve in REW, I am sure the measured response is going to be vastly different. I know I don't have a measured flat response, I still have a bit of basshead tendencies to beat into submission 

I think I just worded my original post about flat response badly.


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## sqnut (Dec 24, 2009)

Most passive xovers split the mid and tweets in the 2.5-3.5khz range, largely to overcome the beaming on the mids. I'm not sure how many sets are even tested in a car. 

The mids and tweets are doing very different things in this range. So with a xover at 2.5 khz @ 12 db slope (like the pio comps), 1.25khz is only 12 db down at the tweet and is in the red zone as far as the tweeter is concerned. You may want to bump 1khz a touch to unveil the vocals and get a touch more dynamics on your mids but with a passive that bump will apply to your tweets as well and the tweets will be adding harshness playing down that low.

The ability to eq the mids and tweets independently around the xover point is vital for a balanced transition. The lowest I have run my scans is 2khz on a 24 db slope. A second order slope at 2.5 is asking too much from the tweets imo. 

This is why in passive mode you might need to start your roll off well below the 1.6khz mark.


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## mooch91 (Apr 6, 2008)

sqnut said:


> But before I go there, I'm curious about what is holding you back from going fully active . Fully active is a huge jump when it comes to tweaking.


Wiring... I have 4 channels of speaker wire running from my amps up to my head unit, but I never wanted to try to get through the molex in the door. It was a decision I made early on that I've been living with since. I've put off even re-mounting my amps/DSP for 6 months now (which is a relatively simple job in comparison), so I couldn't imagine re-doing the speaker wiring (runs along the center under the carpet). I'd want to install a home-run to each of the doors, just too much work than I've got patience for now... 

More to come in a bit, with graphs too...


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## therapture (Jan 31, 2013)

mooch91 said:


> Wiring... I have 4 channels of speaker wire running from my amps up to my head unit, but I never wanted to try to get through the molex in the door. It was a decision I made early on that I've been living with since. I've put off even re-mounting my amps/DSP for 6 months now (which is a relatively simple job in comparison), so I couldn't imagine re-doing the speaker wiring (runs along the center under the carpet). I'd want to install a home-run to each of the doors, just too much work than I've got patience for now...
> 
> More to come in a bit, with graphs too...


I hear ya, I am in the same boat. I need to run more wire to get my tweets fully active, I hate tearing apart my interior + summer heat here in Texas is gnarly. 

Bring on some more system response graphs. I have been following this thread and we have been somewhat on the same paths.


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## Hanatsu (Nov 9, 2010)

This sounds "flat" to me in my car. (This is without sub though). Add 10dB --> 3dB from 20Hz --> 60Hz










Sent from my Samsung Galaxy 3 via Tapatalk.


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## Woosey (Feb 2, 2011)

sqnut said:


> The mids and tweets are doing very different things in this range. So with a xover at 2.5 khz @ 12 db slope (like the pio comps), 1.25khz is only 12 db down at the tweet and is in the red zone as far as the tweeter is concerned.


2.5k is @-3 db so the 1.25k should be around -15db  or am I mistaken? Not much of a difference but still 3 db...

SPL guys would kill for 3 db!!


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## Hanatsu (Nov 9, 2010)

For a butterworth filter, it's down -3dB at the set xovrr point. I think it's different with bessel/L-R for example.

Sent from my Samsung Galaxy 3 via Tapatalk.


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## Woosey (Feb 2, 2011)

Hanatsu said:


> For a butterworth filter, it's down -3dB at the set xovrr point. I think it's different with bessel/L-R for example.
> 
> Sent from my Samsung Galaxy 3 via Tapatalk.


-3 or -6 db if I recall correctly....


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## mooch91 (Apr 6, 2008)

I promise I'll get some more graphs soon...

I wanted to let folks know what I've been exploring though: I put the RTA away for a little bit and just started EQ'ing.

I've created a bit of a valley in between 800 Hz and 3000 Hz. I've found that a lot of the harshness has disappeared and some resolution of the lower and higher frequencies has appeared. A little bit different than what I've been working with in the past.

As I was reading last night, I came across something related to my recent EQ adjustments that I haven't heard mentioned too much at DIYMA: the "BBC dip". A lot of folklore about what it is and its purpose, but I found it particularly interesting that Audyssey builds this midrange adjustment in to their program to overcome some passive crossover challenges (although the relevance seems to go beyond passive crossovers). 
https://audyssey.zendesk.com/entries/410117-Midrange-Compensation

This was the observation I was hoping to show with my graphs: all of my "reference" systems have shown a degree of valley/depression somewhere in the 800-4000 Hz range. I've been tuning for flat here and now realize that my personal preference may be for something other than flat here. And just steadily rolling off from midrange through treble is not enough.

Wondering if my passive setup is the primary cause. Or perhaps my measurement technique is under-representing this region.

Graphs later...hopefully!


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## Hanatsu (Nov 9, 2010)

Audesseys "midrange compensation" seems a bit generalized. They assume that the crossover point is around 2kHz and that the dispersion a vastly different between the drivers here.

Our ears are as most sensitive to frequencies in the 2-4kHz area. Any peaks or dips will be noticed quite easy there. Don't reduce too much or you will lose "clarity" in the midrange.

Think alpine imprint used midrange compensation in their target curve. Sounded dull when I used it IIRC. All cars and setups are different though.

Sent from my Samsung Galaxy 3 via Tapatalk.


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## Woosey (Feb 2, 2011)

Hanatsu said:


> All cars and setups are different though.


So are ears...


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## sqnut (Dec 24, 2009)

Woosey said:


> 2.5k is @-3 db so the 1.25k should be around -15db  or am I mistaken? Not much of a difference but still 3 db...
> 
> SPL guys would kill for 3 db!!


It's a flat response at xover point hence 12 db down at 1.25. Even if it was 15 db down, less than 24db down is audible and 1.25khz from the tweeter is pure distortion. Maybe your ears are more forgiving than mine.......


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## sqnut (Dec 24, 2009)

mooch91 said:


> I promise I'll get some more graphs soon...
> 
> I wanted to let folks know what I've been exploring though: I put the RTA away for a little bit and just started EQ'ing.
> 
> ...


Pretty much what I was telling you. Forgive me cause my posts didn't have the Audessy stamp on it. Outa here.


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## mooch91 (Apr 6, 2008)

sqnut said:


> Pretty much what I was telling you. Forgive me cause my posts didn't have the Audessy stamp on it. Outa here.


Sqnut,

Your advice is what prompted me to start pulling down the midrange. The findings I had afterwards at the Audyssey website and elsewhere when I read of the "BBC dip" were the first I had seen anyone formally suggesting a depression in the midrange as a valid "target". Most of the conventional wisdom points to flat in the midrange with roll-offs below and above. For me, and the way I was measuring it, that strategy is horribly harsh. 

The Audyssey connection doesn't bring it any more validity for me - simply an observation that it isn't discussed much.

Disappointed to see you take it so personally.


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## sqnut (Dec 24, 2009)

mooch91,

one day you will mentor someone and you will have the same hiccups along the way.....lol how does it sound now?

Arun
pronounced as Aaron...


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## sqnut (Dec 24, 2009)

Hanatsu said:


> This sounds "flat" to me in my car. (This is without sub though). Add 10dB --> 3dB from 20Hz --> 60Hz
> 
> 
> 
> ...


try rolling off the response from ~1khz up.


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## sqnut (Dec 24, 2009)

If you have the cd listen to private investigations. Make a note of how the piano sounds.....


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## therapture (Jan 31, 2013)

If mooch doesn't mind, since we are posting response curves...here is mine. I am going to work on that odd hump in the 175-200 range and raise the 400 a bit per hanatsu's suggestions, but I am really happy with this sound. I previously had the 2k-10k range falling off more, but the sound was simply flat and boring, it had no pizzaz, no high end crispness. I thought it was funny that my curve ended up where it was, I was expecting something...different, I actually thought the high end was going to be much...higher...in relation to the rest of the curve. To me it looks like I did actually create the "valley" between 800-3000, I had never heard of the audyssey compensation before, I just know my ears are pleased with where I am at.

This curve came from EAR tuning over several revisions. Now I just want to see if I can refine it a bit and make the curve smoother. I love the low end so I don't really want to mess with that right now.










mooch, looking at your latest curve in which you had harshness, to me it didn't look like it should have sounded that way.

Thanks all contributing in this thread, sqnut, hanatsu, and all the others, I am learning a lot.


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## sqnut (Dec 24, 2009)

therapture said:


> If mooch doesn't mind, since we are posting response curves...here is mine. I am going to work on that odd hump in the 175-200 range and raise the 400 a bit per hanatsu's suggestions, but I am really happy with this sound. I previously had the 2k-10k range falling off more, but the sound was simply flat and boring, it had no pizzaz, no high end crispness. I thought it was funny that my curve ended up where it was, I was expecting something...different, I actually thought the high end was going to be much...higher...in relation to the rest of the curve. To me it looks like I did actually create the "valley" between 800-3000, I had never heard of the audyssey compensation before, I just know my ears are pleased with where I am at.
> 
> This curve came from EAR tuning over several revisions. Now I just want to see if I can refine it a bit and make the curve smoother. I love the low end so I don't really want to mess with that right now.
> 
> ...


Play with 160hz and do this by ear. Make incremental cuts of 1 db each side, keep going and see how the overall sound changes. 

160 is a real pita to get right. When you cut here, your first reaction may be sense of loss in bass. Bear with it for a bit. Good bass is always tight. It's easy to make the bass fat. But tight and fat takes some doing. At the eq and at the ears. The ears have to start loving tight at the cost of some fatness. This is what you should think while cutting 160. If you go too far with the cuts you'll get paper thin kind of sound. No fatness. You don't want tight without a touch of fat.

160-200 can add a lot of faux bass to the sound, but it's more boomy than tight. If you get rid of the hump at 160-200, you won't really have a major dip at 300.


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## Hanatsu (Nov 9, 2010)

Agree on 160-200Hz being a PITA. Heard few cars which sounded right in this area. Lots of room modes ends up there...

Sent from my Samsung Galaxy 3 via Tapatalk.


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## therapture (Jan 31, 2013)

Well, I am sitting in my car right now jamming a bit. Ill have to say I made a few minor changes based on both of you guys suggestions. 

1. I ended up -3db @160, and @ 400 +2db
2. Reversed phase on sub using the 3sixty.3
3. Added 7ms of delay to each side of the mids.

I'll post some observations in a bit...it's sounding nice!


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## Hanatsu (Nov 9, 2010)

therapture said:


> Well, I am sitting in my car right now jamming a bit. Ill have to say I made a few minor changes based on both of you guys suggestions.
> 
> 1. I ended up -3db @160, and @ 400 +2db
> 2. Reversed phase on sub using the 3sixty.3
> ...


Sounds great!


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## therapture (Jan 31, 2013)

The overall sound is just a bit crisper/tighter. I could really hear the vocals sharpen up when I added a little at 400. I was surprised it got crisper but not harsher/louder.

The 160 cuts cleaned up what the Imagines are doing in the midbass, all without losing the midbass! This also cleaned up Beth Hart's low, husky/sultry voice, without losing the warmth that makes her so fantastic to listen to. The bass line from the mid's is quite enjoyable and articulate, playing deep into the upper bass, even with no sub it has presence. This seems to integrate with the sub changes below and really get the bass into the top of the dash.

I could only add 7ms delay to my mids after reversing sub phase, I was at LH 2.95ms and RH .95ms, so I added as much as I could and still have a tiny bit of room for fine tuning if needed, so that's 9.95ms - 7.95ms respectively.
The first thing I noticed about the delay changes was..._I needed less sub level to get it balanced with the mains_. And the changes DEFINITELY brought the bass more up front and invisible (less sub level helps here as well?). This change came about from hanatsu's interpretation of my excess group delay here http://www.diymobileaudio.com/forum/1904325-post35.html

Overall, I made a nice improvement and I want to measure the response this evening to see if it is reflected there as well. I keep learning and doing more with help from you guys, and I am really jazzed with my stereo system.

edit: thanks again for the continuing help and information...


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## sqnut (Dec 24, 2009)

therapture said:


> .....so that's 9.95ms - 7.95ms respectively......


That is a 2ms delay between the drivers, which roughly translates into a PLD ~27". Kind of high, unless you have a really wide cabin. From your seated position measure the distance to L and R speaker and see what is the actual PLD.


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## therapture (Jan 31, 2013)

sqnut said:


> That is a 2ms delay between the drivers, which roughly translates into a PLD ~27". Kind of high, unless you have a really wide cabin. From your seated position measure the distance to L and R speaker and see what is the actual PLD.


It's a wide, low car. I have a visibly drastic pld diffference from my head. I have taken measurements, I'll dig them up...

FWIW, my center image is pretty tight right now.


edit: the pld was right at 90cm I am pretty positive. I will get my son to help me measure again to verify.


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## subwoofery (Nov 9, 2008)

sqnut said:


> That is a 2ms delay between the drivers, which roughly translates into a PLD ~27". Kind of high, unless you have a really wide cabin. From your seated position measure the distance to L and R speaker and see what is the actual PLD.


x2, I'm using door locations and I can't see your car being 3 times what I have... 

Kelvin


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## Hanatsu (Nov 9, 2010)

Try reduce T/A and play with the "balance" control. Noticed that L/R EQ setting might sometimes mask an incorrect T/A setting, but once both are set correctly - the sounds "stack" (male/female vocals recorded in mono for example) upon eachother in the center, no matter if it's lows or highs 

I actually decreased the right side by 1-5dB from 1,5-20kHz compared to the left side.

Sent from my Samsung Galaxy 3 via Tapatalk.


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## sqnut (Dec 24, 2009)

Like Hanatsu mentioned, balancing L/R eq will give you a phantom centre image. However listen with your eyes shut and see if you feel the sound pulling a bit left and right towards the speakers. This despite having a centre. When you've balanced L/R and TA is correct you will not be able to locate your speakers based on what you are hearing.


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## therapture (Jan 31, 2013)

Roger that guys, I will be making measurements this afternoon to verify. That number came from a scrap of paper in my "file" of tuning history, it might just have been an example of something I was working on and not a "real" number...


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## Hanatsu (Nov 9, 2010)

Try a mono speech with some random dude talking. Import into audacity, place a 4th order lowpass @ 800Hz. 

Play it back in the car, set T/A. It should be in the acoustic center.

Sent from my Samsung Galaxy 3 via Tapatalk.


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## therapture (Jan 31, 2013)

I have used the IASCA and Autosound test tracks, the ones where they say "my voice should be center/right/left etc." to help dial in TA. 

Also the mono test track where two instruments are playing.

I bet I am going to find some improvement though...you guys have a way of showing me my errors.


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## Hanatsu (Nov 9, 2010)

All those tracks do have information above 800Hz. Take one of those tracks and set your crossovers temporarily at 800Hz/24dB. Then you take much of the L/R EQ out of the picture.

You can do the same thing with highs and set a ~2000Hz/12dB highpass to see if the FR is centered properly.

Sent from my Samsung Galaxy 3 via Tapatalk.


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## therapture (Jan 31, 2013)

So I measured a PLD of 50.8cm. I was wrong on the number. 

Well that is about 1.48ms of difference, so I just tried to pop that differential into my mids, I set the right to 8ms and then the left to 9.48ms to have a listen.

The image is far too left biased. I imagine I may have to compensate for the distance between my ears as well...so I started trying different values. I increased the delay on the left to move the image right, and then the right side was reduced, until I started getting close. I was not looking for a number, I was just trying to line it up.

Well, I need some fine tuning, but I think I am very close at LH 9.55 - RH 7.83
That's a 1.72ms difference, a substantial amount less compared to the prior 2ms gap. What's amazing to me is how much the image can change with just a couple ms adjustment to either side. I am one of those guys that likes razor sharp center image at the expense of pure tonality, so I am very critical of center image changes. Not sure if that's good or bad. I am guessing the phase changes are what is happening with the TA adjustments? And that is why the image can move several inches with just a small change...or am I totally off here?

I'll do some testing tomorrow afternoon with lots of music, both driving and critical listening, even though I'll have to do it at idle, it's ****in' hot in S. Texas right now and A/C is critical.


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## Hanatsu (Nov 9, 2010)

When imaging is right tonality should improve. You might have to re-adjust L/R EQ now when you changed T/A. Try fine adjusting (one-side) EQ in the area 250-650Hz ((if you measured the area equal in amplitude then it shouldn't require much work, perhaps 1dB +/-)) and then fine-adjust T/A again... repeat and repeat again. It's a tedious process...

Sent from my Samsung Galaxy 3 via Tapatalk.2


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## therapture (Jan 31, 2013)

Hanatsu said:


> When imaging is right tonality should improve. You might have to re-adjust L/R EQ now when you changed T/A. Try fine adjusting (one-side) EQ in the area 250-650Hz ((if you measured the area equal in amplitude then it shouldn't require much work, perhaps 1dB +/-)) and then fine-adjust T/A again... repeat and repeat again. It's a tedious process...
> 
> Sent from my Samsung Galaxy 3 via Tapatalk.2



I can see that...it seems if I cut 1db from the entire left level it gets the "center of warmth" to line up a bit better, but the high end drifts a bit right. I guess I have a slight lean to the right. So I will try the 250-650 cut on the left side.

edit: what I mean is, right now with the TA changed, the lower end midbass/upper bass "focus" is a bit towards my lap while the vocals seem centered. Therefore the "lean". I'll get some solid listening in though beofre I change anything, as I go through my normal repertoire of music. 

It's 5:13am here, time for me to run! Then work today, so I'll report back this afternoon.


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## sqnut (Dec 24, 2009)

Not sure how you measured, but try left speaker from left ear and vice versa. Most, door mounted speakers would need a ~ 0.7 to 1.2 delay between them. There will be exceptions of course. The difference mostly comes from differing cabin width, how far up or down they are mounted on the doors, your height etc etc. 

If the centre shifts left reduce the delay from the near speaker. Thereby reducing the delay between the speakers. The shift could be because the speakers are out of phase or there is a L/R imbalance. However, unless you've majorly played with the eq since you've had the image at centre, I'd go with the phase issue. 


Just play with TA for a bit, you will 'hear' when it snaps into place. With your speakers in phase if the L/R balance is out, you will hear and see that better as well. 

You're lucky in that you don't have to do it separately for mids and tweets and then for mids and tweets either side etc.


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## Hanatsu (Nov 9, 2010)

Try (as an experiment) lowering the right side 2dB from 1500Hz to 5-6dB rolloff beyond 5-6kHz (i e not equal FR). Recently tried this and it improved the center of upper harmonics dramatically. This might sound a bit strange to some but it does really work. 

You don't need to cut the entire area 250-650Hz by 1dB on the left side. It might be a slight dip on the right side at some band so it needs a boost by ~1dB instead. Experiment some 

You could also try correlated pink noise and set crossovers to a bandpass 200-800Hz 24dB both ways. Do you hear sound coming directly from a speaker or off center? All sound should be coming "stacked" over eachother in the center.

Sent from my Samsung Galaxy 3 via Tapatalk.


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## therapture (Jan 31, 2013)

sqnut said:


> Not sure how you measured, but try left speaker from left ear and vice versa. Most, door mounted speakers would need a ~ 0.7 to 1.2 delay between them. There will be exceptions of course. The difference mostly comes from differing cabin width, how far up or down they are mounted on the doors, your height etc etc.
> 
> If the centre shifts left reduce the delay from the near speaker. Thereby reducing the delay between the speakers. The shift could be because the speakers are out of phase or there is a L/R imbalance. However, unless you've majorly played with the eq since you've had the image at centre, I'd go with the phase issue.
> 
> ...


I measured from left ear to left speaker, and right side the same, not taking into account the width of my considerable noggin 

Just a bit ago, I tried reducing the left side delay, and it got even more left biased and sounded funny as the phase shifted. I think I am very close, I did however, shorten the right delay from 7.83 to 7.73 and it improved.

The "snap" into place has occurred, I can really tell with the upper midbass and male vocals...the only problem I have had is dialing in the sharp focus dead center. The sound has definitely thinned a bit like noted further up, after the minor eq changes you and hanatsu had me work on, but clarity has improved. I might have gone a bit too deep on the 160hz cut, I am at -4db and I think I liked the -3db better.

I am trying to get my co-ax setup dialed before I even think about going component. I think a 2 way front is going to be challenging enough for my noobness.


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## therapture (Jan 31, 2013)

Hanatsu said:


> Try (as an experiment) lowering the right side 2dB from 1500Hz to 5-6dB rolloff beyond 5-6kHz (i e not equal FR). Recently tried this and it improved the center of upper harmonics dramatically. This might sound a bit strange to some but it does really work.
> 
> You don't need to cut the entire area 250-650Hz by 1dB on the left side. It might be a slight dip on the right side at some band so it needs a boost by ~1dB instead. Experiment some
> 
> ...


I will try that as well. I am so close it seems, my left side just seems a bit louder, so dropping the entire left side (or moving balance 1 click right on the HU) really helps center up. The minor TA change I made on the way to work a bit ago seems to be better, I just need to get some listening in before I change anything else.

The bandpass xover check looks promising, I will definitely do that later today. My level balancing seems good, I ran a range check from bottom to top, once past the 1000hz and up, it's pretty centered, only the lower ranges seem a bit left, almost like my left leg/footwell area is a bass trap.


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## therapture (Jan 31, 2013)

UPDATE:

Using the bandpass 200-800 and the correlated pink stuff, I found some improvement. Currently I am sitting at 9.5 RH and 7.75 LH delay for a differential of 1.75ms. No matter what, any closer than that and the center is diffuse and starts sounding out of phase, a +/- .1ms adjustment to either side noticeably loses sharpness of the image. I will need to fine tune in .01 or .02 from here on out. 

I also did some minor EQ on the left, cutting both 400hz by 1.5db and 160hz another 1db, this moved the midbass "thump" to the center instead of trapping it at my lap/right leg area. I also raised the right 160hz and 400hz 1db, the midbass is better anchored to the middle and the snap is high up, where a dash center channel would be. 

The tonality is not changing (that's good) and things are lining up better. THANKS you two for sticking with this thread. Mooch, I hope some of my stuff helps you, I know your trials and troubles have helped me.

I need to work on the high end a bit, I think I can get level balancing better, my LH vs. RH plots show some larger differences that I think should be closer, but it is sounding pretty good.


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## Hanatsu (Nov 9, 2010)

Sounds great 

Sent from my Samsung Galaxy 3 via Tapatalk.


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## therapture (Jan 31, 2013)

I'll post some response plots in the next couple days...I need to take a full on measurement set again to make sure I got a clean reading.

I'l say that it's really starting to shape up, I have an actual stage with some width and depth now. So much to learn, so much to tweak, the addiction is strong in me.


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## therapture (Jan 31, 2013)

I am going to measure the system tomorrow, but I spent some time on the TA today. I want to state my impressions before I see what the response is showing. 

I am now at a 1.60ms gap between my mids (9.55 LH and 7.95 RH) so that's quite a difference from the 2.0ms gap I had prior. Vocals have definitely sharpened, and I can steer the center point l/r, without losing sharpness by a +/- .05ms adjustment to both sides. 

I worked on some minor EQ level balancing, by ear, and I think I found that my left side was just too strong, adding some harshness. I cut several areas on the left side trying to find the problem areas, and I have found a much softer, but still crisp, high end. My left leg moving around does not affect it as much as before. I might have to add a tiny bit back to the left side, I need some listening time to verify though.

My sub is integrating very nicely still, and I find I am using less sub, only on the third light of the 3sixty.3 remote level control. I might need to drop the gain a bit on my amp? Having a couple more clicks available would give me a finer resolution possibly.

More to come...


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## therapture (Jan 31, 2013)

*UPDATED with measurements*

OK, I have spent some time working on the system. Before I did these measurements, I also deadened my entire roof panel after dropping the headliner. It defiinitely stopped a ton of resonance.

I am using my mic at my right ear, to measure the right side, and vice versa for the left side. I also measured the sub the same way, taking readings from both right and left ear positions.

I think I am getting the two sides matching alot better. The sound is crisp and I have a nice defined center image. The only odd thing is my sub has an odd hump at ~110hz...I tried cutting that band but it really didn't make a difference in the measurement. Since I deadened my roof, perhaps this is a remaining resonance from somewhere coloring the response?

Another odd thing (or maybe not) is that when I measure the entire system from RH and LH ear/mic positions...the left side shows a huge hump from ~150-350 hz. But when checking level balance by ear wth tones/pink noise...it sounds even.

Here you go, the mids are shown with no sub, purple is RH side, green is LH...oh yeah, I forgot to mention that I am very pleased with the sound. I have everything I have been chasing, fat and defined midbass, fat but tight sub response, crisp detailed highs/vocals, and snap. I am amazed at where I am now, compared to where I was a month ago.











And then the system response, blue is the LH mic position, green is RH mic position. Crazy hump.










EDIT: here are the RH system excess group delay as measured from my right ear, and then the left ear. I understand the principle, but my sub still has that big delay, and reversing phase via the 3sixty.3 did very little. Should I swap the physical polarity and try that?

entire system EGD with mic at right ear









entire system EGD with mic at left ear


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## therapture (Jan 31, 2013)

HEY! I found out what the weird 110hz hump on my sub is...

...it's my car engine/exhaust...it's too fracking hot right now in South Texas to attempt a "windows up, no AC" measurement session!

No wonder tuning attempts didn't do ****...I don't think my dsp can EQ a 6.0l exhaust tone hahaha...

It might even have something to do with the left side hump, I will check that out later this mornign as well.


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## Hanatsu (Nov 9, 2010)

Hm... there's an issue I've noticed when measuring at the ears. You need to measure at both ears and average them with a bias towards the "main ear". For example, if you measuring left side - do an eight sweep measurement and hold the mic around the left ear 6 times of 8 and the other 2 at the right ear. 

The reason for this is that we actually hearing quite much with the right ear from the left side and vice versa. Until I did this I had to readjust the L/R EQ by ear every time to gain an acceptable center image. Note that the driver side have higher "crosstalk" between the ears than the other side, it always a good idea to tune the far side first then match the left side afterwards since that's the tricky one to get right.

Kinda "back-engineered" this method since I tuned by ear, then measured to see how I should measure to gain close to equal FR. I found the above methodology to be closest to what we're actually hearing (it showed similar bumps in FR that wasn't audible, especially at the left side). I gotta do more research before I decide if this is repeatable every time or not though... Btw, you don't have to make eight separate measurements, just select 8 sweeps in the "measure" tab in REW (if you don't have it, upgrade to the latest beta).


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## therapture (Jan 31, 2013)

I spent some yesterday (~3 hours) time working on my system, very carefully getting the level balance correct. I spent a lot of time clicking the balance on the HU back and forth to make sure what side was louder/softer, and I ended up cutting the entire right side from ~1500k on up, between 1-1.5 db. Now using pink noise tracks, I can stack my ranges on top of each other. Still, with music, I was having a weird pull of the high end to the right and vocals, especially female, drifted a bit. How can test tracks be centered, but music wasn't? Well, I figured I needed something else, so I went to work on TA, since you guys got me focusing on that. 

I was just messing with the differential, making big changes to see what it did, and I started to zone in on something...I was still having a solid center but with a...fuzziness...and a drift to the right side, on certain music. I was making smaller changes, and....

*EUREKA!* The center image _*snapped*_ into focus, like I never had it before. I thought I was very close before, but this was a huge difference. The whole thing just "fell into place". Even the issue I was having of the right side seeming too strong in the very high end, disappeared. It sounds like I have a tweeter in my rear-view mirror, that upper end range is so spot on I can't believe it. 

The midbass, while good before, SNAPPED into focus and is so defined that listening to my prior setup is like WTF. It also made the sub anchor to the dash like never before and the doors are so strong I can be happy with the sub turned off. I can't wait to show off to my pals that think I am nuts spending hours tuning and fixing install issues.

Sorry to gush, I was literally excited when I hit that sweet spot!

Right now, I have a differential of 1.62ms from left to right (9.1 right-7.48 left) and the phase seems so in tune with each speaker that flipping the sub phase while it's playing makes the sub volume literally disappear. Same thing with the mids, I can flip it in the GUI and the midbass disappears and vocals are coming from both sides.

I just keep learning and learning and learning... Maybe one day I can stop calling myself a n00b.


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## Hanatsu (Nov 9, 2010)

Nice! I made a few test tracks that's much easier than the correlated pink noise. It's basically pink noise (correlated) that I've used a very narrow bandpass, peaking at every center frequency from 250-3000Hz. Much better than sine tones. With tones it's hard to center a band since it might differ if you go 2-3Hz up and down, but with PN centered around those frequencies the centering can easily be heard! I can see if I can upload these so you can download them, pretty easy to do in Audacity otherwise... ^^ 

But good work rapture!


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## Abaddon (Aug 28, 2007)

therapture said:


> *EUREKA!* The center image _*snapped*_ into focus, like I never had it before. I thought I was very close before, but this was a huge difference. The whole thing just "fell into place". Even the issue I was having of the right side seeming too strong in the very high end, disappeared. It sounds like I have a tweeter in my rear-view mirror, that upper end range is so spot on I can't believe it.
> ...
> Sorry to gush, I was literally excited when I hit that sweet spot!


That magic moment is what all the hard work is for.



therapture said:


> I just keep learning and learning and learning... Maybe one day I can stop calling myself a n00b.


Anyone doing this for 30+ years, and still being honest with themselves, would admit they still have lots to learn too.


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## sqnut (Dec 24, 2009)

Abaddon said:


> That magic moment is what all the hard work is for.


Except that 95% of the magic moments turn out to be a mirage





Abaddon said:


> Anyone doing this for 30+ years, and still being honest with themselves, would admit they still have lots to learn too.


Amen!!


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## Hanatsu (Nov 9, 2010)

...and you wanna improve something three days later anyway lol

Sent from my Samsung Galaxy 3 via Tapatalk.


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## therapture (Jan 31, 2013)

Hanatsu said:


> ...and you wanna improve something three days later anyway lol
> 
> .



**** man, you got that right. Even after my "eureka" moment a few days ago, I have STILL found improvements, mainly working on the 1800-2200 and 7000-8400 range for the high end balance. It seems to be very tricky to get it "just right" especially the left side since my leg causes reflections and an overly bright presentation if it's in the wrong place.

But damn, this is the best sounding stereo I have ever had....


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## highspeed (May 4, 2012)

I see there has been a lot of talk on this thread about time alignment. Does REW have the ability to measure TA? If not, what program is capable of measuring TA so you can align every driver to one spot?


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## Hanatsu (Nov 9, 2010)

highspeed said:


> I see there has been a lot of talk on this thread about time alignment. Does REW have the ability to measure TA? If not, what program is capable of measuring TA so you can align every driver to one spot?


You can T/A with REW. You need to loopback the input/output on the soundcard to get a reference signal first. I made a thread about it actually, just check my started threads in my statistics...


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## highspeed (May 4, 2012)

highspeed said:


> I see there has been a lot of talk on this thread about time alignment. Does REW have the ability to measure TA? If not, what program is capable of measuring TA so you can align every driver to one spot?


cool. I've been looking for this info, thanks for posting. I'll check out your threads.


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## mooch91 (Apr 6, 2008)

OP back again...

Breakthrough? Duh moment? I'm not sure...

I've been continuing to tweak for weeks. Things are getting better. More balanced. Harshness gone. Trying to bring more of my front mids in to the picture and less of the sub. 

But just when I think I've got it, there's one particular area that surprises me - sub to mid integration. I'll get a great sound on one song and crap on another. Figuring I must have too much of something or too little of another, I'll make an adjustment and it will seemingly get worse.

I've described the actual sound before in this thread - very mechanical, not natural in nature. Almost like speakers breaking up, but not quite. Sometimes I'd get too little impact, some times it was too hard. Never in between.

I believe there was something significant in my measurements (and mentioned in the earliest parts of this thread) that I had been ignoring, figuring it wasn't correctable and that it couldn't be significant. It became very apparent in a recent measurement.

See that dip at about 70 Hz?









I knew that dip really couldn't be corrected with EQ. I had tried in the past. But I never thought much of it. I also knew that it created very a very strange situation at 80 Hz. I've described it as a pronounced "cancellation" earlier in this thread, observed when listening to sine tones. 

I now know that this was the source of my frustration, and inability to get natural sounding bass when adjusting. I'm confident that I've been trying to "fill in" this dip by making adjustments across the range and probably only making it bigger and more pronounced. Hence the reason for the artificial sound. A lot of energy at 40 Hz with this dip in between was creating a hard sound. A lot of energy at 100 Hz with this dip in between was softening and fluffing the sound. I couldn't get it balanced.

What was my solution? Time alignment.

Mojozoom gave me some advice back in post 123 that I took without really understanding (not that his advice was bad, it just didn't apply directly to my situation). He suggested, based upon his experience, that T/A between the right mid and sub was a critical first step. In my case, it was the left mid and sub.

I had done all of the recommended rainbow plots for the right mid and sub T/A and found that a T/A of 0 between the two seemed to be about the best - this was the point where they achieved max summation around the crossover frequency. So I left the two at 0 and T/A'ed the left and right mids to achieve a center image by delaying the left by about 1.6 ms. I took this as correct and have been running this way ever since.

So last night I did some T/A with my ears. Knowing that ~80 Hz was a problem frequency, I put an 80 Hz sine tone on repeat. I then isolated right mid and sub and played the tone through both with current EQ. Sure enough, as I moved off of 0 T/A, the 80 Hz tone faded. For the first ms or two, it wasn't dramatic, but a clear cancellation developed at 3.5 ms+ delay on either of the two.

Next I isolated left mid and sub and repeated. What do you know, at my current T/A setting, the 80 Hz tone was very faint. Sounded like the sub was dominating and the tone was coming from behind me. I began to increase delay on the left mid and the tone came back and pulled up to the front. Crossed 4 ms and the tone started to disappear again. Left it somewhere around 3.5 - 4 where the tone was most pronounced.

Since I knew the left-right delay needed to be about 1.6 ms on the right, I set my right delay at 2.4 ms. Conveniently, there wasn't much difference in output between the sub on the right side at this delay.

The output was a "holy crap" kind of moment. The bass was definitely not dialed in, but it was PRESENT. I had impact and boom and was able to run the volume dial way up without any unnatural sound. Drums didn't sound like cardboard any more, the rhythm of the bass line in a song was clearly detectable. Subtle change in my measurement - the dip at 70 Hz (from about 55 - 95) filled in. Doesn't seem like much, but WOW what a difference (interestingly, my overall system response now looks identical to what I get when I ask REW to sum my sub response with my front response).










Now to just reshape the curve at the low end and see how it sounds.

I think I may have found the "smoking gun" I've been looking for. I'd love to hear any comments or thoughts from you guys about what I've found.

Thanks.


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## therapture (Jan 31, 2013)

Oh yes. Time alignment can indeed give that EUREKA moment. Now you need to run an entire system "excess group delay" and see how your sub and mids align to each other. I have ~20ms delay on the low end, so I was able to increase my delay on the both sides (while keeping the same differential between them) up near the max delay to lessen the gap. Result? More up front bass and integration.

So in essence, I was running the right side at 0ms delay and the left side at 1.6ms delay. By going to 7.55ms delay on right, and 9.15ms on the left, I keep the same differential between mids, which keeps midbass response intact. Now instead of a 20ms delay between sub and mids, it's closer to 10-12 ms. My 363.3 only has a max of 10ms delay per channel.

I might try swapping polarity on the sub and/or phase on the mids to see if I can close it up even more.

Did you see my waterfall plot in another thread? It's worth looking at, especially on the sub response to see if you have any weirdness showing up.


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## Hanatsu (Nov 9, 2010)

To integrate sub well the delay should be about the same as the mids, both the distance and group delay of the sub add to the arrival time to the front seat, the easy way to find out what delay different frequencies have to each other is to observe the excess group delay as rapture mentioned 

Group delay is less audible in the lows than than it is in the midrange for example. Also a slow change in GD is less audible than a sudden jump in delay several milliseconds. Just as it is with irregularities in the FR, high Q GD peaks/dips are less audible. Most subs have increasing GD with lower frequencies, especially vented alignments. As long as the delay stays below one half cycle of the corresponding frequency I find it to be kinda inaudible really. For example, the full cycle for a 50Hz tone is 20ms. 20/2=10ms, if the GD is above 10ms at 50Hz then you should consider it an issue.

Most of the mid/sub integration is EQ work though, if you have sorted out the timing issues, start with EQing the right mid to the sub, turn it off then EQ the left mid to the sub, at the crossover point the amplitude should be equal (both sides, very important). Modal ringing, vibrations, sloppy output from the mids, sub distortion among other things can destroy the upfront bass feeling. I had good results using my rear speakers as bass cancellation devices delayed in time, killed lots of the modal ringing (after hours of complicated and frustrating tuning, nowhere close where I want it anyway... YET). Creating bass is child's play in a car, creating upfront good realistic bass is less... easy =/


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## therapture (Jan 31, 2013)

I tried dropping the sub xover to 65hz today...since I had moved my mids up to 85hz, I was getting some audible distortion in the bass heavy songs, trying to drive my Imagines too hard. 

As far as integrating, I actually think I lost some of the upfront at higher volume levels, which doesn't seem to make sense. I set up back to back EQ presets with only the sub xover changed from 75 to 65, I will play around with it a day or two.

To cure some of the sub egd, I think I should try to reverse polarity on it and see what happens, and test to see which setting integrates better.

I also may need to revisit my sub EQ, measure it both ways and see if I can get some improvements there as well.


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## Hanatsu (Nov 9, 2010)

Ifyou losing upfront bass at higher SPL it's most likely distortion from the sub. If you increase the LPF on the sub it's more likely to produce distortion higher up in frequency. 3rd order HD at 50Hz is 150Hz but 3rd order HD at 80Hz is 240Hz.

If you lose upfront bass by lowering LPF on he sub it's most likely the mids that can't keep up SPL wise.

Sent from my Samsung Galaxy 3 via Tapatalk.


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## therapture (Jan 31, 2013)

Hanatsu said:


> Ifyou losing upfront bass at higher SPL it's most likely distortion from the sub. If you increase the LPF on the sub it's more likely to produce distortion higher up in frequency. 3rd order HD at 50Hz is 150Hz but 3rd order HD at 80Hz is 240Hz.
> 
> *If you lose upfront bass by lowering LPF on he sub it's most likely the mids that can't keep up SPL wise.*
> 
> Sent from my Samsung Galaxy 3 via Tapatalk.



Hahaha, you mean I just can't keep cranking the knob further and further and make "mo bettah" sound?


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## mooch91 (Apr 6, 2008)

mooch91 said:


> OP back again...
> 
> I think I may have found the "smoking gun" I've been looking for. I'd love to hear any comments or thoughts from you guys about what I've found.


I had a chance to really listen this morning. Things are very cool. I think the previous situation was pulling many of the lower frequencies to the right and rear. The front left is now filled in - I'm thinking this is a very important outcome, despite the fact that the lower freqs are not so directional, because it's so close to my seating position.

Another observation I had is how full the bass actually is. I know this isn't the true test of an SQ system, but my rear view mirror never really saw much action when I was playing music at moderate volume. Always figured this was because of the size of my truck or just the limitations of my system. The thing nearly wanted to vibrate off the glass this morning. 

And I can make adjustments too - without creating a distorted, artificial sound. +2 here -2 there and it doesn't fall apart like it was doing.

Very excited and looking forward to some cooling off (it's been near 100 here the past week) so I can fine tune it!


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## Hanatsu (Nov 9, 2010)

therapture said:


> Hahaha, you mean I just can't keep cranking the knob further and further and make "mo bettah" sound?


You summed it up quite well xD

Sent from my Samsung Galaxy 3 via Tapatalk.


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## mooch91 (Apr 6, 2008)

Now tackling another issue...

Any thoughts on the massive 200 Hz dip I have in my overall system response? It doesn't appear when the drivers are playing independently, only when they play together. It's exacerbated when I time align to center the image. It's definitely noticeable when playing sine tones - 160 Hz is hot, 200 Hz is dead. 

Very similar to my experience at 80 Hz, but not something I've been able to address.

Thanks.


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## sqnut (Dec 24, 2009)

How's everyone doing?


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## Hanatsu (Nov 9, 2010)

Nulls around 200Hz are common, if it occurs when you use both mids, then it's because the frequencies around 200Hz are close to 180deg out of phase in respect to the other side. Try phase inversion on one side, it will most likely dissappear but you'll screw up other frequencies instead so basically you can't do much about it.

Sent from my Samsung Galaxy 3 via Tapatalk.


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## therapture (Jan 31, 2013)

Hanatsu said:


> Ifyou losing upfront bass at higher SPL it's most likely distortion from the sub. If you increase the LPF on the sub it's more likely to produce distortion higher up in frequency. 3rd order HD at 50Hz is 150Hz but 3rd order HD at 80Hz is 240Hz.
> 
> If you lose upfront bass by lowering LPF on he sub it's most likely the mids that can't keep up SPL wise.
> 
> Sent from my Samsung Galaxy 3 via Tapatalk.



I have played around a bit with sub xover and slope. I have ended up at 60hz and for most of my "electronica", and some southern rap music (don't hate lol) it sounds cleaner and still retains nice "punch". I can also go LOUDER on the sub level without pulling the image rearward. Also, my mids are definitely happier at an 85hz xover since I tend to listen to music fairly loud, the 75hz setting just seems to give me too many door noises without any more midbass output. I will be taking some measurements of both changes over the weekend and post them here. Seems like a big underlap? I probably should re-tune for the 60hz setting and see where I end up.

I am also experimenting with a thick towel draped neatly across the dash, so far I think I am hearing an improvement in the high end clarity...I may look funny driving around with it for the weekend, but if I find an improvement I am going to order a dash mat.

mooch, I have a couple dips like that, cancellation comes to mind, hanatsu and others are experts here and could tell you what to look for. I will post my response charts over the weekend so people can laugh at my system, I can tell you though that mine looks way crazier/different than yours. I apparently like a bit more from 2k-5k.


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## highspeed (May 4, 2012)

Hey Mooch, how's the system sounding?


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## therapture (Jan 31, 2013)

Kind of a cross thread post, but I have been working in small steps the last few days on integrating the sub better. What I have found is that using the L-R crossover at 48db on both mids and sub, reduces group delay on the sub, and is getting me better integration and some really good upfront bass! I ended up lowering the xover on the sub to 70hz and moving the mids up to 82hz. Slight underlap but it sounds really good. Now it's time to break out the mic and REW and verify some things. I know there is improvement to be found.

I was previously using a butterworth filter and have that tune saved as a reference, but I am finding it was just a bit bass heavy in the mid area, the new setting is cleaner/sharper and more upfront.

More to come...maybe next week, I am going to Dallas Saturday and prob won't have time to get the car mic'ed again.


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## ecbmxer (Dec 1, 2010)

This is a really great thread. So much general tuning advice and techniques! I'd also be interested in hearing how the OPs system is sounding these days?


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## Brian Steele (Jun 1, 2007)

therapture said:


> Kind of a cross thread post, but I have been working in small steps the last few days on integrating the sub better. What I have found is that using the L-R crossover at 48db on both mids and sub, reduces group delay on the sub, and is getting me better integration and some really good upfront bass! I ended up lowering the xover on the sub to 70hz and moving the mids up to 82hz. Slight underlap but it sounds really good.


This sounds reasonable. I'm guessing that the usual in-car subwoofer bass "dip" occurs around that range of frequencies in your car, and you've basically minimized or eliminated its impact by using such steep filters at that point. I'm tempted to try the same in my car. I did try something similar in a past, with shallower slopes. It sounded fine, but lacked any serious dynamics, as the midbass speakers up front could not keep up as I increased the volume.


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## therapture (Jan 31, 2013)

Brian Steele said:


> This sounds reasonable. I'm guessing that the usual in-car subwoofer bass "dip" occurs around that range of frequencies in your car, and you've basically minimized or eliminated its impact by using such steep filters at that point. I'm tempted to try the same in my car. I did try something similar in a past, with shallower slopes. It sounded fine, but lacked any serious dynamics, as the midbass speakers up front could not keep up as I increased the volume.



I actually am at 70hz on the mids now, but it seems a bit low for some of the bass heavy electronic material I listen to when I get volume knob happy, I am going to test 75hz. After some serious auditioning earlier this evening, it is working pretty well.

I flipped back and forth between my old tune of the BW xovers and while not huge, the new L-R setup is indeed easier to keep the bass up front.'

I do tend to listen fairly loud while driving, my car is a 6.0 V8 and has an aftermarket exhaust that is not obtrusive, but it is louder than your average 4 cyl rice burner! So it takes some beef in the midbass to get the impact I want at highway speeds.

p.s.- nice website, I saw that long before I was a member here.


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## therapture (Jan 31, 2013)

UPDATE: I have been using L-R the past few days and doing some minor tweaking, by ear. I ended up working on time alignment a bit, as well as raising the xovers back to 75hz on both mid and sub. I even knocked down the right side EQ a hair at 2.5k, 5k, and 10k. The combination of these things has resulted in:

1. even better focus on my image, especially vocals, dead center and crisp.
2. the bass is more upfront than I have ever heard from my rig.
3. The midbass is definitely more pronounced and the system, without the sub sounds _damn good_ and has impact. Turning the sub on is nirvana.

I still need to mic it. I got to do extended listening sessions with tons of music, 3 hours at a time while driving back and forth to a marathon over 2 days. Fantastic!

Before I left, I also fixed a nasty rattle from the maplight/headliner that was dragging the image focus away from the top of the dash. Now I need to work on the doors a bit more, the trim cards have a little buzz on certain frequencies, I think I need to seal the mid to it with some thick foam so it doesn't direct some of the prodigious midbass into the cavity between the door card and metal.

I can't day how impressed I am with the Imagines.


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## mooch91 (Apr 6, 2008)

ecbmxer said:


> This is a really great thread. So much general tuning advice and techniques! I'd also be interested in hearing how the OPs system is sounding these days?


As the OP, I'm going to get back in to this thread soon.

I've been away for a while - relocating my home and family for work reasons, and I haven't been behind the wheel of the truck in about 6 weeks. 

I've also re-installed my system, finally permanently mounting the 360.3 and making it so that my amps are easily removable (especially since I know the 500/1 still needs service).

I should have my relo done in a few weeks and have a chance to get back at it.

Bonus situation now is that my new home has a garage that fits my truck. No more late-night tuning sessions out in the driveway in the cold!

Talk with you guys soon...


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