# RTA and REW Measurements Dump



## sicride (Oct 26, 2014)

As I have been learning about tuning audio systems and doing research I have found some really informative threads. I have particularly learned a lot when graphs have been included and I have learned to love looking at frequency response graphs and RTA measurements. Unfortunately, not a lot of people take the time to post them to these forums so it is hard to find a lot of that information. 

I know I am not alone so I am starting this thread so people can dump their RTA graphs and other REW measurements here for others to enjoy and hopefully learn from. 

I recommend when posting graphs to use 1/12 octave smoothing and about 50db range from top of graph to bottom for some consistency between graphs but there are no restrictions on what information you post.

I will start this with a overloaded picture from today's work tuning my 08 Mustang project.

1st Image:








I just changed over to bi-amping my front stage via my Alpine SPX-13REF factory crossovers. I believed this would help with a still overly bright sound I had despite extensive EQ. This graph shows my old final tune vs. flat measurement after bi-amping and final results after 2 days tuning. This worked perfectly to address my overly bright sound while obviously increasing my high frequency output. I suspect the parts in the crossover used to pad high frequencies are responsible for that issue. Biamping aloud me to set the tweeters at 0db on the crossover vs -6db.

2nd Image:








This shows my final measurements including Left and Right independant measurements. Pretty pleased with this considering I do not have L-R EQ capability just level adjustments on tweeters and balance adjustment. I did use 1/6 Octave smoothing for L-R measurements as they were taken with a fixed mic position.

3rd Image:








This shows my final measurement vs my target curve which is a combination of the crutchfield curve and JBL/Harman curve. I am aware the bass is too hot, but that is for personal tastes and can easily be brought down as necessary since my mid-bass is currently on the subwoofer output and X-over is at 160hz.


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## Justin Zazzi (May 28, 2012)

Why do you think your bass appears to drop so quickly below 50hz?


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## sicride (Oct 26, 2014)

I have a pair of 8" factory speakers in the door, but they are in their own small enclosures approx .4cu.ft. So they do roll off pretty steep. To be honest, I don't miss much below that at this point. I am still really questioning if I'll ever add subs to this car.


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## jnorman5 (Apr 7, 2013)

Sub'd. I am about to get into some heavy tuning and this could be very helpful. Great idea!!


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## sicride (Oct 26, 2014)

I hope it does and I hope you contribute anything and everything you like. I have a whole new set of measurements I took today of some new speakers I have that are not installed yet. I hope you ask any questions you may have, maybe I can help you and more likely you will end up helping me in some way.


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## percy072 (Feb 13, 2014)

So I thought I was going in somewhat prep'd today after dropping in my new GZ Nuclear mids...set up the laptop, mic and using pink noise from an Alpine reference CD this is what I got?? 

After a while I started feeling stupid and ear fatigue setting in so I called it a day. 

This is the whole system playing without any EQ, only some basic speaker leveling and after using auto TA with the H-800...look fairly normal? 



I'm getting the feeling I'm going to be doing tuning by ear cause this (for me) is hard to interpret out of the gate. I'm still not sure where or how to establish a "baseline" as a reference for judging what are actual problem peaks and/or where to start cutting??


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## sicride (Oct 26, 2014)

Well something appears to be off on your measurement, not quite sure what the problem is. I can assure you if you used a 50 dB range on your graph instead of 200 dB it would look even worse. Describe your measurement setup and technique so we can help identify the problem. What mic are you using do you know you have the calibration file setup properly in rew? Can you take a measurement with a digital silence track and post that graph? That would be considered your noise floor if it is accurate.


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## percy072 (Feb 13, 2014)

I did goof on the wrong db range. I am using the umik mic with a calibration file downloaded from MiniDsp. 

What I don't understand is...I'm just sitting here with nothing on in the house and the RTA it is measuring over 50db's...wtf 

Just took this reading...


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## Hanatsu (Nov 9, 2010)

percy072 said:


> I did goof on the wrong db range. I am using the umik mic with a calibration file downloaded from MiniDsp.
> 
> What I don't understand is...I'm just sitting here with nothing on in the house and the RTA it is measuring over 50db's...wtf
> 
> Just took this reading...


Got the mic plugged into a laptop? Try disconnect the power adapter. The peaks at 60-120Hz might be rumble leaking in from the net. You got 60Hz power grid in the US right?

Is the mic laying on a soft surface? Might pick up vibrations otherwise. Could be an issue with the mic itself causing that LF noise.


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## percy072 (Feb 13, 2014)

Hanatsu said:


> Got the mic plugged into a laptop? Try disconnect the power adapter. The peaks at 60-120Hz might be rumble leaking in from the net. You got 60Hz power grid in the US right?
> 
> Is the mic laying on a soft surface? Might pick up vibrations otherwise. Could be an issue with the mic itself causing that LF noise.


The mic is sitting in the little tri-pod that comes with it. I tried unplugging the laptop's power supply...no change.

Using REW's tone generator...it will measure and show the exact frequency being played, but the standing LF noise (with nothing else on) is a head scratcher.


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## sicride (Oct 26, 2014)

I feel like I've run into this before but don't remember a particular fix for it. Have you tried disconnecting your mic, rebooting the pc and then once windows is back up plug in the mic, then open reward and choose your calibration file?

It's pretty obvious there is a problem when you are getting a negative dB measurement at some frequencies... A noise floor between 35 dB and 45 dB is pretty normal but it's still gonna be much flatter across the spectrum. 

Did you try to calibrate your sound card? If so try deleting that calibration if the reboot thing doesn't work.


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## percy072 (Feb 13, 2014)

I'm hoping it's some dumb simple thing I'm not aware of...I just did this RTA with the computer speakers using REW's pink noise generator? That peak around 180hz is showing 55db's on the graph, but the meter was usually reading 15-20db's higher. The graph and the "real time" db meter are not in sync? 



This "real time" db meter I'm referring to is shown in the upper right side of the graph screen (just above the window were you'd adjust the smoothing etc) but not shown in photo. 

If I get home in good time tomorrow...I'll try taking some RTA's in the car.


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## sicride (Oct 26, 2014)

Ok that's looking a lot better. What changed? Not sure about the spl reading in the corner it may be reading an peak that is only seen with no smoothing.


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## ssclassa60 (Jan 28, 2013)

My latest curves
Stock bmw ib10s
SI TM65
BG Neo8

















I just added the tm65s and need to raise the overall level of the neo8s by around 3-4dB. 80Hz needs some help too


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## sicride (Oct 26, 2014)

Yep looks good and sounds like you got some in the bank for the highs. I fear you'll need a little more than 3-4 dB up there. Might need a few cuts from 100hz-500hz too. But sounds like a real nice setup and pretty smooth.


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## sicride (Oct 26, 2014)

Here comes a big dump!

So, I have some new and old speakers I wanted to do some testing to compare. Lets be clear here, I do not have an anechoic chamber and I am not an engineer of any sort. I did however try to keep measurement techniques consistent between measurements for comparable data purposes. They can not be compared to any thing else you may have seen for drivers on the internet, just between each other reliably.

The Hertz HSK165 component set and my Alpine SPX13REF component set.

Lets start with raw frequency response sweeps of drivers without Xovers

HSK165









SPX13REF









Comparing mids at same volume (used home audio receiver for testing) for output, distortion, and dispersion or cone breakup? I'm not sure which is really shown.

HV165 (Hertz Mid) vs SPX Mid Frequency Response









HSK vs SPX Distortion:

HV165









SPX









I was surprised to see the Hertz 6.5" driver has higher distortion overall and breaches 1% distortion at a higher frequency than the smaller SPX 5.25" driver.

Dispersion (Measured at 0, 20, and 45 degrees off axis):

HV165









SPX









Also surprising that the 6.5" driver seems to go higher in frequency before off axis response varies drastically versus the 5.25" driver. Distortion increases also around the same frequencies for these drivers. Again I'm not even really sure what exactly that is demonstrating but always thought it would be the opposite.

I also hear a lot of people asking about swapping tweeters when one is blown out from a set. So, I decided to hook the SPX tweeters up to the HSK crossovers and then measure with the HSK mid as if I had swapped the SPX tweeters into the setup. We can see why this is advised against.

Both tweeters on HSK crossover









HSK mid with both Tweeters









To be honest I think with some tweeters this could obviously be worse if the resistance varied more they may even have a greater difference in crossover points. However, you can see there is some adjustment in the crossovers to improve the hump around 1k on the HV165 driver. This effected phase and when adding the HT25 tweeter to the crossover smooths things out. If you add the SPX tweeter, it appears there is a phase issue which actually makes that peak re-appear and causes a cancellation on the other side of the crossover point. Where the two measurements cross is actually the crossvoer point, this I verified with swapping polarity of the tweeters.


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## percy072 (Feb 13, 2014)

Cannot understand (what looks like) significant high and low peaks?? It actually sounds better. My inexperience say's I should be cutting and boosting all over the place to get things looking smoother...

...sigh :blush:


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## strohw (Jan 27, 2016)

It looks like you need to adjust your levels more than anything. Bring mids and subs down and the graph would "look" better.


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## percy072 (Feb 13, 2014)

strohw said:


> It looks like you need to adjust your levels more than anything. Bring mids and subs down and the graph would "look" better.


OK makes sense...should be getting things a little closer to horizontal. It's trying to figure out those wicked dips ie: Purple line @ 700hz etc 

Didn't expect a straight line...but that's just jagged as f**k lol


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## sicride (Oct 26, 2014)

Couple questions, something is wrong still with that measurement. You have almost 40 dB variance from sub bass to your highs. I would start by taking a measurement at a higher volume. Say 1khz at about 75-80 dB. Next change your dB range to either 40 or 50 to 100 dB. 

As far as jagged response curve:
- What octave smoothing are you using?
- How are you measuring? Is this with the mic held at a single point or are you taking an average with the RTA while sweeping the mic from left to right ear?


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## Hanatsu (Nov 9, 2010)

percy072 said:


> Cannot understand (what looks like) significant high and low peaks?? It actually sounds better. My inexperience say's I should be cutting and boosting all over the place to get things looking smoother...
> 
> ...sigh :blush:


Use "Var" smoothing, then look at the curves again. You must either average multiple measurements or smooth a single point measurement to get somewhat near the actual response.


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## percy072 (Feb 13, 2014)

sicride said:


> What octave smoothing are you using?
> - How are you measuring? Is this with the mic held at a single point or are you taking an average with the RTA while sweeping the mic from left to right ear?


Was using 1/12 smoothing, didn't seem to show any different curve when sweeping the mic so I held it just in front of my nose.

I'm starting to wonder if it's the mic, calibration file or REW itself because I don't understand that major drop from Sub to high's either??? In fact...in the car it's still a little on the "bright" side and I've reduced the db's on the mids and sub using the DSP.


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## percy072 (Feb 13, 2014)

percy072 said:


> What I don't understand is...I'm just sitting here with nothing on in the house and the RTA it is measuring over 50db's...wtf


I might e-mail miniDSP if they have any idea's...something could be contributing to what may show as a boosted low end reading??

This is an RTA reading with the mic set up on it's tri-pod in the house with nothing on...where/why is it picking up this strange 47db reading that drops off at 3k??


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## sicride (Oct 26, 2014)

I always say start with a reboot. Make sure your calibration file is selected in preferences. Make sure the mic you want is selected for the input device. Make sure your mic sensitivity is turned up to 100% in the control panel.

You can tell those readings are unreliable because the tweeter has the same rise as the mids and sub from 20-400hz. Maybe you're better off posting these in the hometheatershack forums to get a quicker more accurate answer.

Also, your old graphs no longer appear in this thread. Can you fix that so people who have similar problems in the future can use this as a resource?


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## sicride (Oct 26, 2014)

What are you using to generate the pink noise?

I remember when I tried to use the headphone jack on my laptop I got measurements very similar to this because it is actually a headphone/microphone jack. If that is the case find another way to produce the pink noise. Play the track on a cd or USB.

This is sound card feedback of some sort.

We can also trouble shoot by unplugging one thing at a time and measuring. First thing I would unplug is anything hooked up to the headphone or microphone jacks. The mic is hooked up through the Usb so make sure other jacks have nothing in them. Then if still the same frequency response plug those things back in and unplug the mic, if it'll let you take a measurement let's see what you get.


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## percy072 (Feb 13, 2014)

Using pink noise from an Alpine reference CD (in the car)...

I've got this mic with a calibration file downloaded from miniDSP

https://www.minidsp.com/products/acoustic-measurement/umik-1

I will try RTA again using the mic's 90 degree cal. file...otherwise it still picks up this phantom noise floor. I'll keep trying, hopefully things will start making sense.


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## Hanatsu (Nov 9, 2010)

percy072 said:


> Was using 1/12 smoothing, didn't seem to show any different curve when sweeping the mic so I held it just in front of my nose.
> 
> I'm starting to wonder if it's the mic, calibration file or REW itself because I don't understand that major drop from Sub to high's either??? In fact...in the car it's still a little on the "bright" side and I've reduced the db's on the mids and sub using the DSP.


Shouldn't sound bright with that overall slope. I'd pull down the 1,6-2,5kHz region like 7-10dB and pull up tweeter level by at least 5dB and leave the rest as it is as a baseline.


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## percy072 (Feb 13, 2014)

OK...made some change's in the Preference's window on REW. This is an RTA taken a minute ago, again mic on it's tri-pod, nothing else on.

This looks a little better for a quiet baseline?? I think that spike at 52 is probably the cooling fan on the laptop...



In preference's under "soundcard" set output device and output to "Speakers", input device "microphone UMIK-1"...and set buffer to 64k?? Was hoping it was just something stoopid I didn't do


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## sicride (Oct 26, 2014)

Oh my goodness yes that's wayyy better. Let's see a real RTA average. Set it to unlimited averages and swipe ear to ear until the line stops moving. Usually from 50-80 avgs. That will go quicker if you change FFT length to 16k


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## percy072 (Feb 13, 2014)

Best I could do was use REW's PN generator on my garbage computer speakers...but it should show that it's at least reading properly.



Will be able to get back to doing some RTA's in the car tomorrow (again)


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## sicride (Oct 26, 2014)

There is still a problem. Your noise floor is higher than that. I bet under your control panel the volume for the mic input is not at 100%. I also checked my preferences and my buffer is set at 32k. Don't really know what difference that could make. If you compare those two measurements you'll see that it is suggesting there was 0 dB output from your speakers from 4k up.


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## percy072 (Feb 13, 2014)

sicride said:


> There is still a problem. Your noise floor is higher than that.


HUH!!...wtf!?! I dunno...I can't find any volume settings for the mic in the preference' window? I just downloaded it a couple weeks ago so I'm wondering if it's a little different (updated) version than what you have?

Will post some result's today and see if anything is making more sense. Really appreciating the help on this guys...nothing "simple" in this hobby


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## strohw (Jan 27, 2016)

percy072 said:


> HUH!!...wtf!?! I dunno...I can't find any volume settings for the mic in the preference' window? I just downloaded it a couple weeks ago so I'm wondering if it's a little different (updated) version than what you have?
> 
> Will post some result's today and see if anything is making more sense. Really appreciating the help on this guys...nothing "simple" in this hobby


It's to the right of the buffer for your input device. Check the control input volume button then you can adjust the input level there. However, that is the same thing as going into your sound preferences in Windows and adjusting your MIC input volume there. If it stays grayed out in REW then just adjust it through Windows.

Soundcard Preferences


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## percy072 (Feb 13, 2014)

K...back at it again  Got some tips on HTS and adjusted how I'm using REW. Not sure if the curve show's it but I am giddy with how much better things are getting. Solid imaging, great midbass impact, very good separation (bass guitar etc...) Also used the tape measure and math formula for TA...auto TA was ok, but it's much better now.

Don't know that I can get anything more "flattened out" or "aligned"...maybe some more tweaking but ended up making some heavy cuts with GEQ and PEQ to get to what you see. Was still a little hot in the upper midrange (2.5khz-4khz)but knocked that down a little already.

Now I'm really digging this hobby! just wondering how much "better" it can get??


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## SkizeR (Apr 19, 2011)

from another thread on the topic of mic placement when taking measurements..



SkizeR said:


> so now that im home from colorado, ill show you what i was talking about before. the first graph is measured with pink noise in rew's RTA while moving the mic around both ears.
> 
> 
> 
> ...


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## strohw (Jan 27, 2016)

I would verify the sweeps first. They can be a little finicky depending on your hardware. Do a RTA in one location then do a sweep in the same location with only 1 sweep average and 128k length selected. Not a 2 sweep average and 256k like the it defaults to.


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## sicride (Oct 26, 2014)

Thanks for sharing SkizeR. 

Percy those measurements look a lot more accurate. Glad you figured it out. Wish I could have been more help. I think things can be a lot better still on this setup. Let's start with some raw driver measurements all EQ/levels flat. Also I imagine you are running active so try low volume measurements with the tweeter crossover very low and very steep and no high pass on the mid. I think if we perfect the crossovers and driver levels alone we could get closer than it is now. We are going in the right direction for sure. Be sure to save this setup incase we screw everything up, but I'm pretty sure we won't. I know the mids levels are off at the least, dropping the green mid 3-4 dB alone will help drastically. The purple tweeter can come down probably 2 dB and then there will be just a few peaks to knock down to equal things out. Again probably best to kind of start over.


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## SkizeR (Apr 19, 2011)

strohw said:


> I would verify the sweeps first. They can be a little finicky depending on your hardware. Do a RTA in one location then do a sweep in the same location with only 1 sweep average and 128k length selected. Not a 2 sweep average and 256k like the it defaults to.


thats how i had it set. heres more with measurements with the mic about 1-2 inches apart for each measurement


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## sicride (Oct 26, 2014)

That reminds me percy, how are you measuring? Are you doing RTA averages while sweeping the mic between ears and playing pink noise?


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## strohw (Jan 27, 2016)

SkizeR said:


> thats how i had it set. heres more with measurements with the mic about 1-2 inches apart for each measurement


I wish we weren't in the middle of a snow storm right now. I'd take 10mins and go outside to do a comparison to see how close my sweep and rta measurements are. Are you using Java or ASIO?


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## SkizeR (Apr 19, 2011)

strohw said:


> I wish we weren't in the middle of a snow storm right now. I'd take 10mins and go outside to do a comparison to see how close my sweep and rta measurements are.


i have the convenience of having a decent computer setup to play with lol


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## percy072 (Feb 13, 2014)

sicride said:


> That reminds me percy, how are you measuring? Are you doing RTA averages while sweeping the mic between ears and playing pink noise?


Yes...I was sweeping ear to ear holding mic as straight up as I could. I should figure out how to include what line is what ie: green line is Left midbass. I was playing a WAV file of REW's Pink PN noise (recommended by the author of REW) seems to be very stable for averaging.

I must have something causing some heavy reflections in the car...or whatever is causing that?? Getting those dips and peaks to flatten out took alot of EQ'ing. Left mid seems all over the place! Big dip @ 150hz, swan dive from 300-400hz, and those three peaks? could not get those to budge. 

Also need to learn when to apply Parametric, Graphic and/or both (usually) I will be out tomorrow to try your suggestions and record the data. Thanks


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## sicride (Oct 26, 2014)

When you click capture you can make the selection to show the legend. The dip in the 150hz range for the drivers mid is normal and not able to be fixed from what I understand. With the RTA technique discussed and with 1/12 octave smoothing, it really shouldn't end up that difficult to EQ flat. We'll see.


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## SkizeR (Apr 19, 2011)

ok this is strange. has anyone noticed this? i was messing around in the rta function and switched from spectrum to rta 1/12. same measurement, different results. like, 12db swing on the top end different


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## strohw (Jan 27, 2016)

Ya, sorry I didn't even think to ask you. You want to run the RTA in RTA mode not spectrum. I don't know why it defaults to spectrum. I'm sure you've already read up on the differences but here is a link to explain it more:

Spectrum/RTA feature - Home Theater Forum and Systems - HomeTheaterShack.com


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## percy072 (Feb 13, 2014)

^That was one of the recomendations I got from JohnM (REW author) is to use RTA and not spectrum...

RTA Phantom noise floor or setup issues?? - Home Theater Forum and Systems - HomeTheaterShack.com

No idea why...but it helped with getting my measurements to start making sense.


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## SkizeR (Apr 19, 2011)

i dont think ive ever seen anyone using rta over spectrum. weird


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## Justin Zazzi (May 28, 2012)

Spectrum can be used with white noise. RTA can be used with pink noise.

You can also use periodic pink noise "PN Periodic" and then you don't have to use any averaging if you want a true real-time analysis that changes as you move the microphone. Just make sure the FFT length of the generator and the RTA match eachother to get this effect.


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## SkizeR (Apr 19, 2011)

gotcha. thanks guys. i always figured it sounded a little heavy up top. simple fix. now it looks like this


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## Kazuhiro (Apr 28, 2015)

SkizeR said:


> i dont think ive ever seen anyone using rta over spectrum. weird


I thought everyone picked RTA for a car environment?


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## SkizeR (Apr 19, 2011)

Kazuhiro said:


> I thought everyone picked RTA for a car environment?


whenever i see pics of measurements it always seems to be spectrum measurements


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## Hanatsu (Nov 9, 2010)

Spectrum and RTA display the same data differently. It shouldn't differ as long as you use the same excitation signal. RTA measurements doesn't need smoothing if you measure enough points in the listening space. I have always used spectrum display. Same data as averaging/smoothing multiple sweeps basically.

All corrections done in the higher frequencies should be done with low Q filters so an 1/3 octave smoothing is probably a good practise there.


Skickat från min iPhone med Tapatalk


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## Niick (Jun 3, 2015)

SkizeR said:


> ok this is strange. has anyone noticed this? i was messing around in the rta function and switched from spectrum to rta 1/12. same measurement, different results. like, 12db swing on the top end different


there is a simple explaination for this. It is a function of the fact that by scaling a linear process (FFT) on a logarithmic scale we are then forcing more and more data points (as frequency rises) into each frequency bin of the RTA graph. The lower bins or bars of the RTA might have only a few data points to sum up and define its level, where as the higher frequency bands or bars of the fractional octave display (RTA) will have hundreds or thousands of data points per bar, thus resulting in a higher apparent level.

There is simply more and more energy in each bar as frequency rises. 

Programs like Smaart allow you to see the raw FTT data and the fractional octave banded data simultaneously. Doing so then makes it easier to understand this appearent discrepancy.

EDIT: SkizeR, by the way, unless you're using period matched noise (periodic pink noise of the same sequence length as your analysis FFT size) then you should be windowing that data. Hann is a good choice for RTA and random noise. "Rectangular" is essentially the same as "no-window" which is ideal for period matched noise, but not random


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## Hanatsu (Nov 9, 2010)

I'm a bit lost here. White noise contain the same amount of energy at all frequencies in a given range. Displayed on a spectral analysis is will be flat. Pink noise contain the same energy per octave and will have a 10dB/decade fall on a spectrum analysis. This is the excitation signals I'm talking about. 

So having said that, you guys say that the RTA VIEWING mode alters this? I was under the impression that RTA view mode only takes portions from the spectrum and display it as a bar for easier viewability. I have measured with RoomEQ for years and never noticed differences between rta and spectral view mode. Would be laughable if I've missed this. I will check this later to confirm it...


Skickat från min iPhone med Tapatalk


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## percy072 (Feb 13, 2014)

sicride said:


> Let's start with some raw driver measurements all EQ/levels flat. Also I imagine you are running active so try low volume measurements with the tweeter crossover very low and very steep and no high pass on the mid.


OK this is all eq and x-overs off, still can't figure how to show what line is what 

Anyhow

purple=left mid
pink=right mid
blue=left tweeter
orange=right tweeter...
sub is low but it's dialed back on the RUX still


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## SkizeR (Apr 19, 2011)

Hanatsu said:


> So having said that, you guys say that the RTA VIEWING mode alters this?


thats what im experiencing. the spectrum vs rta i posted earlier is the exact same measurement, different results as i switch modes


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## SkizeR (Apr 19, 2011)

Niick, how exactly do you window it


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## strohw (Jan 27, 2016)

SkizeR said:


> Niick, how exactly do you window it


Look under FFT Length on your RTA settings. This page explain the RTA settings.

RTA Window


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## SkizeR (Apr 19, 2011)

im not seeing any difference in measurements with different window settings


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## Niick (Jun 3, 2015)

SkizeR said:


> im not seeing any difference in measurements with different window settings


 the difference is in the underlying mathematics of how the signal is processed before being displayed. The difference will be easily seen if you use a single tone. Sweep the tone slowly and as you come to the center of an FFT I bin, all the side "splash" will go away and you'll see a single spike. This is a result of the tone being having an integer number of cycles compared to the FFT size. This experiment will probably be easier with smaller FFT sizes. 

Using a window (the proper window, Hann is a good one for random noise) with random excitation signals is the "correct" way to do it. If, like me, you tested a large number of different things, from different cars to different electronics, acoustic and electrical measurements, then you would come across times where using an unwind owed measurement DOES result in inaccurate data.

When you only have a single system to try it on, yeah, you might not see much of a difference. In instances like this, what I do is consult scientific manuals and documentation written by those who DO have the experience and understanding to help me decide why one setting is preferred over another. 

Which reminds me, when I get back to work, I'll post (if I can remember) a perfect example of what we were discussing a while back, correlated vs. uncorrelated noise. 

In a manufacturer's demo car I recently tuned, part of my "pre-tuning evaluation" is to determine and quantify how significant the differences are in frequency response between the different sources. Since this car had Bluetooth, cd, and line in (aux), I wanted to know if I tuned it for one source, how might that adversely affect another source. Since the DSP in use didn't use presets. 

Anyways, while doing this I made simple single channel spectrum measurements of correlated and uncorrelated pink noise, on each source, with a single mic, and the difference is significant. 

Now, if that mic would have been EXACTLY half way between the speakers (physically OR in time) then there would have been no difference. But the mic was in the drivers seat listening position.


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## Niick (Jun 3, 2015)

Hanatsu said:


> I'm a bit lost here. White noise contain the same amount of energy at all frequencies in a given range. Displayed on a spectral analysis is will be flat. Pink noise contain the same energy per octave and will have a 10dB/decade fall on a spectrum analysis. This is the excitation signals I'm talking about.
> 
> So having said that, you guys say that the RTA VIEWING mode alters this? I was under the impression that RTA view mode only takes portions from the spectrum and display it as a bar for easier viewability. I have measured with RoomEQ for years and never noticed differences between rta and spectral view mode. Would be laughable if I've missed this. I will check this later to confirm it...
> 
> ...


youre not lost. You get it. You just said it yourself. Fractional octave banded displays pink noise as a horizontal line. The underlying FFT which is used to PRODUCE the fraction octave banded chart, if you simply plot IT's data points on a chart, pink noise will then have a downward slope. 

Simple experiment, take an ELECTRICAL measurement of pink noise, and look at it with REW's RTA mode set to spectrum(smoothing doesn't matter in this experiment, it won't change the "tilt" of the line) then switch it to fractional octave banding.


----------



## SkizeR (Apr 19, 2011)

thats weird, cause if you remember last time, the measurements came out almost identical. to be fair, i took them at my computer setup with the mic in the center. i did it again, but off to the left to replicate a car. same result. only a slight difference between 700-1.3k and extremely miniscule differences elsewhere which can probably just be attributed to moving the mic slightly different for the two measurements. at what point does all this measuring become trivial? i think after a basic RTA measurement your at the point of diminishing returns


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## Niick (Jun 3, 2015)

SkizeR said:


> thats weird, cause if you remember last time, the measurements came out almost identical. to be fair, i took them at my computer setup with the mic in the center. i did it again, but off to the left to replicate a car. same result. only a slight difference between 700-1.3k and extremely miniscule differences elsewhere which can probably just be attributed to moving the mic slightly different for the two measurements. at what point does all this measuring become trivial? i think after a basic RTA measurement your at the point of diminishing returns


Nope, the differences in car are huge. I'll show ya tomorrow.

EDIT: look at the combing going on from 40-100 Hz, that should tell you something. If changing from correlated to uncorrelated (or vice-verse, one to the other) induces that, then what other changes might it have in a different scenario? Ya know?


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## SkizeR (Apr 19, 2011)

Niick said:


> Nope, the differences in car are huge. I'll show ya tomorrow.


well what about after its time aligned? i cant imagine to much of a difference. also, i think we both know we should only be measuring one speaker at a time, so this is almost (<--- keyword) pointless


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## Niick (Jun 3, 2015)

SkizeR said:


> well what about after its time aligned? i cant imagine to much of a difference. also, i think we both know we should only be measuring one speaker at a time, so this is almost (<--- keyword) pointless


no that's my point bro, AFTER it's time aligned WITH THAT MIC PLACEMENT is the ONLY time when it DOESNT matter. . 

EDIT: that's EXACTLY IT! You got it


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## SkizeR (Apr 19, 2011)

Niick said:


> no that's my point bro, AFTER it's time aligned WITH THAT MIC PLACEMENT is the ONLY time when it DOESNT matter. .
> 
> EDIT: that's EXACTLY IT! You got it


so were on the same page that correlated or uncorrelated doesnt really matter?


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## Niick (Jun 3, 2015)

Yes, you should only be measuring one speaker/channel at a time. HOWEVER, I know for an absolute fact that there are MANY so called "professionals" who don't know this. Or if they do, they don't know why. 

So, that's why. That's WHY one should only measure one speaker at a time.


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## Niick (Jun 3, 2015)

No, there is no difference (it's ALL "correlated") so long as you're only measuring one speaker at a time. That's what the term correlated refers to. A correlaTION of what? Of the timing relationship of the waveform of the LEFT and RIGHT channels. "Correlated" is another way of saying "dual mono".

"Uncorrelated" would be having two seperate random noise generators (one connected to the left, the other to the right) and pushing play on them at two different times. 

If you did that, the signal would be uncorrelated, what is happening at any instant in time on the left is NOT the same thing that is happening at that same instant on the right. 

That's it.


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## SkizeR (Apr 19, 2011)

i dont think were even on the same page. i know what the difference is. a while back you said i shouldnt be using mono pink noise to measure (when in reality, if your measuring one speaker at a time it wont make any difference), but just to see why, i measured both. one from the center, and one from off center. still get very similar results. you pushed using uncorrelated so hard, yet there is almost no difference either way.


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## oabeieo (Feb 22, 2015)

Niick said:


> No, there is no difference (it's ALL "correlated") so long as you're only measuring one speaker at a time. That's what the term correlated refers to. A correlaTION of what? Of the timing relationship of the waveform of the LEFT and RIGHT channels. "Correlated" is another way of saying "dual mono".
> 
> "Uncorrelated" would be having two seperate random noise generators (one connected to the left, the other to the right) and pushing play on them at two different times.
> 
> ...


Isn't uncooralated also put in stereo (10ms delay) between the dual mono, otherwise it would be just mono right ? Other wise the "dual generator" would have to have separate randomness ..

IIRC the IASCA disc is uncorrelated stereo random noise


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## Hanatsu (Nov 9, 2010)

Niick said:


> youre not lost. You get it. You just said it yourself. Fractional octave banded displays pink noise as a horizontal line. The underlying FFT which is used to PRODUCE the fraction octave banded chart, if you simply plot IT's data points on a chart, pink noise will then have a downward slope.
> 
> Simple experiment, take an ELECTRICAL measurement of pink noise, and look at it with REW's RTA mode set to spectrum(smoothing doesn't matter in this experiment, it won't change the "tilt" of the line) then switch it to fractional octave banding.


You're correct. There is indeed a difference, sweeps correlate with RTA mode.

Good that I have not used the RTA function much, otherwise hundreds of measurements would have been failed lol. Well, good that you pointed this out, I stand corrected.


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## sicride (Oct 26, 2014)

percy072 said:


> OK this is all eq and x-overs off, still can't figure how to show what line is what
> 
> Anyhow
> 
> ...


Perfect starting point, you can even change the smoothing to 1/3 octave to set levels. It looks like there is at least 5 dB to cut from left mid and probably 4 dB cut from left tweeter overall driver level. I think you can do better with your crossovers also. What were you crossing at before? I'm wondering if you did Butterworth 12db/Oct with a high pass around maybe 3250 and low pass mid at around 1950? It is best to play around and remeasure so you get the least ill effects. Previously, at least one side had a drastic droop near 2.8k. Changing your crossovers instead of trying to eq around that should be more effective but we haven't really seen the combined measurents either. 

Have you figured out the target curves so you can equipment each channel individually to that desired curve? Really that's preferred before level matching I imagine. When you get to level matching it may be a matter of compromise.


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## percy072 (Feb 13, 2014)

Well...this is what I had before I accidentally linked the Left and Right channels 

So it's way different now...spent a lot of time on it and lost it all with one slip of the finger lol

Also something was off?? way to much "energy" but not alot of substance. Resonance etc. Dunno...think I need a break from this


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## sicride (Oct 26, 2014)

Looks like the left mid will only need 3-4 big cuts to get started. For sure about 8-10db cut around 590hz. Looks like a 4 or 5 db cut around 1100hz. Wide cut around 1800hz of about 6 db, though I could be seeing that wrong with the colors so close. 180-340hz looks a little trickier, it may require 2 bands of parametric eq?

Right side mid probably only needs a cut in the 1600-1800hz range to start. 

Both tweeters look ok.... Except the 2500-300hz peaks. If you knock those down and play with crossovers, you'll probably be getting a lot closer. High pass on the mids might need to be higher than normal to kill some of that lower bloat.

Edit: good work, looks like you did most of what I typed while I typed it. lol.

Your energy is probably from the large peaks still in the midbass region and the 4,500-7k regions.

If you did not cut the blue tweeter in 3-4k range, you may want to match that dip on the other side and re-adjust crossovers if needed to flatten out the transition from mid to tweeter. Always good to take breaks, and often good to start over by choice or not when starting. See what works and retry the things that didn't work as well as you'd like.


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## percy072 (Feb 13, 2014)

Actually have been in the garage for quiet some time today. That energy (I'm wondering) may have been from the charger I was using...maybe a little to much?? 

Those dips in the crossover areas are as close as I could get them on the high end...and no matter what I could not get the sub closer to the mids and did not want to HP the mids anymore below 90hz. 

I will keep trying...the big dip, and three peaks in the Left mid are a b**ch to move!?! Parametric or GEQ would hardly touch them unless I made crazy cut's. I may go back out shortly...I can be tenacious, but after I accidentally linked the left and right channels I got a little...irritated


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## sicride (Oct 26, 2014)

Don't be afraid of big cuts. Be afraid of big peaks. We know those are a real problem because they have shown up in every graph you have. So go kill those peaks! I'm sure it wouldn't hurt to move that high pass on the mids to 100hz or even higher. It looks like you got waaaaaay too much going on down below 300hz still. You also don't have to worry as much about matching L-R response down there, and completely ignore that dip around 150hz on the left mid. Cut around that dip if needed to get the overall frequency response where it's needed though.

Your sub has to have more in the bank than that.. You can turn it up and flatten it afterwards can't you?


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## Niick (Jun 3, 2015)

SkizeR said:


> i dont think were even on the same page. i know what the difference is. a while back you said i shouldnt be using mono pink noise to measure (when in reality, if your measuring one speaker at a time it wont make any difference), but just to see why, i measured both. one from the center, and one from off center. still get very similar results. you pushed using uncorrelated so hard, yet there is almost no difference either way.


again, in YOURE PARTICULAR experiment the difference that WAS THERE, to you, didn't seem that significant. But there was a difference.

In other scenarios, the difference can be quite dramatic. 

I might not have got my message across very well. 

Let me re-state it like this: IF someone is dead set on measuring both channels at a time, and they HAVENT just time aligned the two channels to the mic position currently being used, then if they DONT use uncorrelated noise, the results they'll get WILL NOT be very accurate. HOW inaccurate depends on where the mic is placed. 

It's very simple. it's just comb filtering. 

I can't tell you how many times I've seen or heard of guys using an RTA to adjust an EQ, and that EQ NOT being seperate left right EQ, but being the kind that adjusts both channels at once. And they put the mic in the drivers seat. And they play pink noise. And they are under the impression that the reading they're getting is somehow valid to then make EQ decisions off of. 

It is not.

So, summing up, measure ONLY one channel at a time. If you do this, then it's ALL "correlated"


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## Niick (Jun 3, 2015)

Hanatsu said:


> You're correct. There is indeed a difference, sweeps correlate with RTA mode.
> 
> Good that I have not used the RTA function much, otherwise hundreds of measurements would have been failed lol. Well, good that you pointed this out, I stand corrected.


you got it man!  

Crazy how many things like that might be right under our noses for so long without our even realizing it!


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## SkizeR (Apr 19, 2011)

Niick said:


> again, in YOURE PARTICULAR experiment the difference that WAS THERE, to you, didn't seem that significant. But there was a difference.
> 
> In other scenarios, the difference can be quite dramatic.
> 
> ...


and my next question is.. why in the hell would someone be measuring two channels without setting TA first?


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## Niick (Jun 3, 2015)

SkizeR said:


> and my next question is.. why in the hell would someone be measuring two channels without setting TA first?


the existence of the 'ol audio control SA-305x RTA (and other units, a certain Coustic peice comes to mind) far pre-dates TA being a common thing. Therefore, a lot of "old school" stereo installers have been practicing flawed methods. 

Here is an example, I work with a guy who used to work for a company that at one time had a "shop policy" of sorts that every car, no matter what was done to it, got "RTA'd". 

He told me of this "rule" that apparently was in the company handbook, yet he didn't know whether or not they were using correlated pink noise, uncorrelated pink noise, measuring one channel at a time, or what. (We won't even get into the single mic position used) 

This means that, I can almost say for certain, that MANY, MANY systems were measured inaccurately, and many, many times EQ's were inevitably adjusted to correct for frequency response problems that didn't actually exist.

TA is a relatively new thing. But the (improper) use of RTAs in car audio goes way back.

Oh, that, and many many people, myself included, aren't content to just do something because someone says so. They want to know WHY. So by explaining WHY you don't want to use correlated pink noise in certain scenarios is better (in my opinion) than just telling people "TA first." "Measure one channel at a time." 

"Why?" they'll say.


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## jtaudioacc (Apr 6, 2010)

the God complex is out of control. :laugh::laugh:


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## Niick (Jun 3, 2015)

God complex? Hmmmm.........?? 

Inferiority complex? Hmmmm..........??

I don't know, I'm not a psychologist.

Or is the proper term psychiatrist?

You'll have to elaborate.


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## sicride (Oct 26, 2014)

It would be psychologist, there's no medicine to address inferiority complex. Psychiatrists prescribe drugs, psychologists talk it out or simply study psychology.

I find it funny how RTA is still used to score cars for SQ competitions with fixed mic positions. With or without time alignment it is still not nearly as representative of actual frequency response at the listening position, especially in a two seat setup.


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## percy072 (Feb 13, 2014)

sicride said:


> Don't be afraid of big cuts. Be afraid of big peaks.


Ok...took some of your suggestions and this is latest curves. No idea what happend an hour ago...but it's back to sounding decent again.


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## sicride (Oct 26, 2014)

Hmm that is interesting. I know this process can be frustrating. Glad you're sticking with it. While it does look like the two sides are closer, it does not look like those peaks actually got any smaller. Wonder what happened? We're you using parametric eq or graphic? What frequencies specifically did you cut? Also curious how the one tweeter got this same major dip before the crossover that wasn't as bad last measurement but looked like this when we were trying to restart from yesterday.

So much easier to figure these things out when the computers in front of you huh?

Maybe we should step back from measuring all these different channels until you get that left mid fixed? If you aren't having luck fixing the one problem you're probably wasting your time trying to fix the others. Some of the other "fixes" may even need to be undone if not approached in the right order.


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## percy072 (Feb 13, 2014)

sicride said:


> While it does look like the two sides are closer, it does not look like those peaks actually got any smaller. Wonder what happened?


Using both GEQ and PEQ to try to flatten out that left mid and making really heavy cuts on those peaks...I'm almost willing to swap left and right mids but I have to think it's something in the car. My knee's, steering column?? It is frustrating 

I'm also seeing what must be a boosting affect when everything is playing and probably explains the lingering "muddiness" and resonance at volume...and/or I still just have no idea wtf I'm doing 



Is this typical? Are some cars just a total PIA to tune or are some drivers generally "flatter" out of the box. I know it can take time...but the amount I'm cutting all over the place seems wrong??


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## sicride (Oct 26, 2014)

Can you show a measurement of the left mid then cut 590 or 595hz by 10 dB with parametric eq with a Q of 3 and remeasure? Only show those two measurements.


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## trumpet (Nov 14, 2010)

For your sanity you may want to specify the smoothing level as well.


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## sicride (Oct 26, 2014)

True at 1/12 smoothing is what I'll need to see to cut those peaks down. 

I see why he used 1/1 for that last measurement though. It does show what I was saying about spreading your crossovers and cutting much higher and that will reduce the number of cuts you will have to do in the midbass region. I still think we need to focus on one driver at a time.


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## SkizeR (Apr 19, 2011)

just tested again in a car. same. exact. result... same. exact. differences.

im starting to think its not a difference it response, but just a difference in the track itself


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## strohw (Jan 27, 2016)

percy072 said:


> I still just have no idea wtf I'm doing
> ?


https://www.youtube.com/playlist?list=PL8DsRfMp9q4az_gei9C27aRyUIUvMIMO0


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## ssclassa60 (Jan 28, 2013)

sicride said:


> It would be psychologist, there's no medicine to address inferiority complex. Psychiatrists prescribe drugs, psychologists talk it out or simply study psychology.
> 
> I find it funny how RTA is still used to score cars for SQ competitions with fixed mic positions. With or without time alignment it is still not nearly as representative of actual frequency response at the listening position, especially in a two seat setup.


Great info in this thread, my questions are:

- I have no time alignment (analog processing, L/R 31 band) and I've tuned left and right independent and then together with uncorrelated PN. And then band by band, L/R image balance. Isn't it important to tune in stereo so that any phase response issues/cancellations can be measured and tuned?

- After reading the "where's the center of my stage" thread, how can any car be a two seat setup without a center channel? Even if I tune to a center on top of the steering wheel, the passenger side is usually imaging too far to the right


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## sicride (Oct 26, 2014)

From my understanding the only way to have a good center stage from two seats and not having processing for time alignment is to have equal path lengths to the drivers, at least mids and midbass where phase is more correlated to imaging than sound level below 800hz and equally important from 800hz to I believe 1600hz.

But I'm sure the magician Patrick Bateman has a way to trick our ears otherwise...?


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## percy072 (Feb 13, 2014)

OK...latest "revision" Still cannot get those peaks out of the left mid ie: 600hz area etc...but I'll keep trying. It starts to pull everything around it down with it when I make heavy cuts on those peaks (GEQ and/or PEQ)

Pretty happy with things as they are now...took alot of wierd EQ'ing to get the tweeters more aligned. Still a little sharp on the upper midrange area but I think those Ground Zero Nuclear mids are know for upper midrange. Took a little time with actual music playing making very minor adjusments on the bottom end only.

Hoping it will improve when those mids break in...but I'd like a little more warmth on the low end (or it's my sub?) Had to cross the Right tweeter down to 2.2Khz because it was determined to only start responding at 4.3Khz if crossed any higher and cross left mid up to 4.6Khz to close the gap in response.

Overall...feel not too bad with this

Blue=left mid
Green=right mid
Light blue=left tweeter
Red=right tweeter


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## brumledb (Feb 2, 2015)

percy072 said:


> OK...latest "revision" Still cannot get those peaks out of the left mid ie: 600hz area etc...but I'll keep trying. It starts to pull everything around it down with it when I make heavy cuts on those peaks (GEQ and/or PEQ)
> 
> Pretty happy with things as they are now...took alot of wierd EQ'ing to get the tweeters more aligned. Still a little sharp on the upper midrange area but I think those Ground Zero Nuclear mids are know for upper midrange. Took a little time with actual music playing making very minor adjusments on the bottom end only.
> 
> ...


I haven't read the whole or thread or been keeping up with it so sorry if this is redundant.

Have you tried letting REW give you the EQ cuts needed to get to the house curve? I forget what this feature is actually called.


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## percy072 (Feb 13, 2014)

brumledb said:


> Have you tried letting REW give you the EQ cuts needed to get to the house curve? I forget what this feature is actually called.


Actually no...sicride mentioned about a using a curve but thought that was something downloaded offline and you'd need to make cuts to try to get as close as possible to it??

That definitely sounds like something I should be looking into...thanks!


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## sicride (Oct 26, 2014)

Like you said, you had to do some weird stuff with your crossovers to get rid of the gap. The problem is you need the gap, when both mid and tweeter are playing the same frequency (approx 2800hz) at the same level at the same time and in phase they will constructively create a large peak at that point.








Having different crossovers for one side vs. the other could be a bad idea also. It may be better to match the dip from one tweeter graph with the other tweeters dip using EQ to cut. 

It seems you are absolutely focused on matching your L-R EQ. This can't be done if one speaker has drastic peaks in its response while the other does not. Don't even bother measuring the right side mid or either tweeter until you can fix those 3 peaks in the left mid. The problems highlighted are glaring issues. Nothing else should be touched until those are addressed.

If you don't show what is happening when you try to EQ those peaks on the left mid we can't help you anymore with them. You keep suggesting those are giving you trouble, why aren't we positing pictures about those problems?

Please understand these look a ton better than what you originally had. But the problems that should be addressed first aren't touched.


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## percy072 (Feb 13, 2014)

sicride said:


> It seems you are absolutely focused on matching your L-R EQ.
> 
> Please understand these look a ton better than what you originally had. But the problems that should be addressed first aren't touched.


I thought was kinda the idea?? No body else posting graphs so it's hard to get an idea of what a well tuned curve looks like. I'll keep digging through Diy forums.

I'll research the idea of using a pre-determined house curve (JBL)? And keep trying

I should document what my settings are...but sub is LP @ 71, mids HP @ 100.


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## sicride (Oct 26, 2014)

Sure, in the end you'll want both sides equal. At the beginning you want to focus on each driver individually. Right now you're trying to level match a squiggly line with a flat line. You have to first make the squiggly line flat, then match them up.

I'm sure you could afford to bump that high pass filter up a little more on the mid. See what happens with 120hz. It's good that you have too much energy in that region. If you reduce it, in this case by crossing over higher, you will reduce distortion in that area.


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## percy072 (Feb 13, 2014)

where does one find any of the more popular "house curves" to upload into REW??

having no luck with google


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## brumledb (Feb 2, 2015)

percy072 said:


> where does one find any of the more popular "house curves" to upload into REW??
> 
> having no luck with google


http://www.diymobileaudio.com/forum/technical-advanced-car-audio-discussion/206881-jazzis-tuning-companion-room-eq-wizard.html

Here is a good start, download Jazzi's tool. I have a few more I have found also. Let me see how I can get them to you. You can PM me your email if you like and I'll send those others I have.


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## brumledb (Feb 2, 2015)

percy072 said:


> Actually no...sicride mentioned about a using a curve but thought that was something downloaded offline and you'd need to make cuts to try to get as close as possible to it??
> 
> That definitely sounds like something I should be looking into...thanks!


And here is the other point I mentioned about using REW for EQ work.

http://www.diymobileaudio.com/forum/technical-advanced-car-audio-discussion/144455-quick-tip-using-auto-eq-roomeq-rew.html


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## Hanatsu (Nov 9, 2010)

percy072 said:


> where does one find any of the more popular "house curves" to upload into REW??
> 
> having no luck with google


Try this one... 

Used similar curves in two of my SQ builds with good results. You may like it or... you may not


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## brumledb (Feb 2, 2015)

Here are some more house curves. Be forewarned, I have never tried these or even input them into REW so I could actually "see" the curve.

More House Curves


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## percy072 (Feb 13, 2014)

brumledb said:


> http://www.diymobileaudio.com/forum/technical-advanced-car-audio-discussion/206881-jazzis-tuning-companion-room-eq-wizard.html
> 
> Here is a good start, download Jazzi's tool. I have a few more I have found also. Let me see how I can get them to you. You can PM me your email if you like and I'll send those others I have.


I can download it but it won't open...keeps coming up with some kind of "password required", "close and re-save" etc etc... 

I am not much of a computer guy. 




Hanatsu said:


> Try this one...
> 
> Used similar curves in two of my SQ builds with good results. You may like it or... you may not


Thank's Hanatsu...still trying to learn more about using REW's EQ tool ie: how to manually create a curve?

Feel like a monkey f**ing a football the past couple day's...lol


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## brumledb (Feb 2, 2015)

percy072 said:


> I can download it but it won't open...keeps coming up with some kind of "password required", "close and re-save" etc etc...


Which version are you trying to download? When you go to the page, look at Jazzi's signature and download it from there. He will have the latest version in his sig.


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## sicride (Oct 26, 2014)

percy072 said:


> Feel like a monkey f**ing a football the past couple day's...lol


So.... you're enjoying yourself?:laugh:


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## Justin Zazzi (May 28, 2012)

percy072 said:


> I can download it but it won't open...keeps coming up with some kind of "password required", "close and re-save" etc etc...
> 
> I am not much of a computer guy.


The spreadsheet is password protected against modifying certain cells. You don't need a password to use the cells highlighted in light green. You do have to enable the scripts/macros though.





percy072 said:


> Thank's Hanatsu...still trying to learn more about using REW's EQ tool ie: how to manually create a curve?
> 
> Feel like a monkey f**ing a football the past couple day's...lol


To make your own house curve for REW, open a plain text file and type the following:


```
20 0
25 0
31 0
40 0
50 0
63 0
80 0
100 0
125 0
160 0
200 0
250 0
315 0
400 0
500 0
630 0
800 0
1000 0
1200 0
1600 0
2000 0
2500 0
3100 0
4000 0
5000 0
6300 0
8000 0
10000 0
12000 0
16000 0
20000 0
```
Then change all the zeros to whatever you want, like +10 or -3 etc.
Save that text file, then import it into REW.


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## percy072 (Feb 13, 2014)

sicride said:


> So.... you're enjoying yourself?:laugh:


Oh for sure...

Am I done yet...Har! Still crowed at the mid/tweet but almost ran out of EQ. Left mid and right tweeter were brutal...



Difference in Left mid from yesterday to today...that's about all I could squeeze out of the H-800 on that F**ing speaker!! Ridiculous cuts...and yes boost's to get it where it is


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## percy072 (Feb 13, 2014)

percy072 said:


> Is this typical? Are some cars just a total PIA to tune or are some drivers generally "flatter" out of the box. I know it can take time...but the amount I'm cutting all over the place seems wrong??


Anything on this question??


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## Hanatsu (Nov 9, 2010)

percy072 said:


> Anything on this question??


Not cars. Some installs can be a real pain to get right. I find it harder to get a 2-way sound good than a 3-way. Midrange low in doors or kick panels in cars that have large center consoles always got issues, large holes in the response due to destructive interference etc. Drivers are normally not the cause.

Btw, in your last measurement - pull down 200-300Hz 7-8dB and try to get a smoother transition in that region.

This is the response from one of my cars. Full system. See the gradual transition in the 100-300Hz region.


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## percy072 (Feb 13, 2014)

Hanatsu said:


> Btw, in your last measurement - pull down 200-300Hz 7-8dB and try to get a smoother transition in that region.


Copy that, will see whats left in the H-800...pretty sure I cut that region hard only to get what you see. Could that explain why I have so much "energy" and not hearing as much of the warmer tones as I'd like?? 

Midbass punches but it's a little woody sounding (if that makes sense) 

To bad I can't store my EQ settings on the laptop...that left mid is all over the place!


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## Hanatsu (Nov 9, 2010)

percy072 said:


> Could that explain why I have so much "energy" and not hearing as much of the warmer tones as I'd like??
> 
> Midbass punches but it's a little woody sounding (if that makes sense)
> 
> To bad I can't store my EQ settings on the laptop...that left mid is all over the place!


Cut the 160-300Hz region and that issue will probably go away. It usually cleans up the midbass dramatically as well. With a peak in the 200-300Hz region male vocals often sound very pronounced, "honky" or "in your face". I suck at subjective explanations but I hope you get what I mean


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## sicride (Oct 26, 2014)

That has got to be sounding a lot better and more pinpoint accuracy in your imaging, isn't it? Good work! But no, you're far from done.

I imagine when the mids and tweets play together you still have a decent bump in the 2-5k range? I don't know that I'd be content with the L-R EQ but I would probably start measuring things together to adjust overall tonality a little. See those peaks from the mids right out of the passband at about 4.1k? See if you can knock that down 5 dB or so. That's could sound like "energy".

Btw, 100% agree with Hanatsu about 100-300hz range. He's way smarter than me too, so do his suggestion first.


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## sicride (Oct 26, 2014)

Hanatsu said:


> This is the response from one of my cars. Full system. See the gradual transition in the 100-300Hz region.


Beautiful curve Hanatsu. Is that comb filtering 3k+? If it is, can it be fixed or improved with time alignment? Doesn't look like it'd be very audible either way. Just trying to learn.


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## percy072 (Feb 13, 2014)

sicride said:


> That has got to be sounding a lot better and more pinpoint accuracy in your imaging, isn't it? Good work! But no, you're far from done.


It does, may take a little to adjust to it (like changing your golf swing) feels different. Unfortunately still hearing a little peak in the upper midrange area probably from that mid/tweet collision.



sicride said:


> See those peaks from the mids right out of the passband at about 4.1k? See if you can knock that down 5 dB or so. That's could sound like "energy".


This high energy I'm referring to feels like the midbass' are under tension...I'm feeling the midbass in my legs, arse and back through the car seat?? Almost like it's getting a ton of power and was wondering if that's associated with that 200-300hz region?


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## percy072 (Feb 13, 2014)

Hanatsu said:


> With a peak in the 200-300Hz region male vocals often sound very pronounced, "honky" or "in your face". I suck at subjective explanations but I hope you get what I mean


That's actually a pretty accurate description of what I'm hearing. Also...is it better to start EQ'ing from one end to the other rather than jump all over chasing peaks?


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## sicride (Oct 26, 2014)

I don't thinks it's a big deal to work on a whole drivers frequency range at once, taking the biggest peaks out each measurement. Sounds like you know what you need to focus on next. Keep us posted. Looks good. 

For the next set of measurements drop the sub by itself and add the whole kit at once (sub, mid, tweeter) for each side. For readability you might want to adjust those measurements to be 10-15 dB higher than the individual driver measurements. Gotta see how things are interacting.


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## Hanatsu (Nov 9, 2010)

sicride said:


> Beautiful curve Hanatsu. Is that comb filtering 3k+? If it is, can it be fixed or improved with time alignment? Doesn't look like it'd be very audible either way. Just trying to learn.



Not all combing are caused by incorrect set delays. It was so long ago I measured that I don't even remember what the issue was. If I had to take a guess I'd say destructive interference from reflections. If the frequency response isn't really close to eachother there will be issues showing up in combined side measurement (sweep or RTA/cor noise). I only had my P99rs to eq with back then, with my new setup there are almost no holes in response outside the modal region. 

The modal issues can be fixed by multiple speakers located in different places in the car but that's probably overkill for most people.


Sent from my iPhone 6 using Tapatalk.


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## Hanatsu (Nov 9, 2010)

Rule of thumb;

*Rather cut than boost.
*Never boost in a non-minimum phase region.
*High Q peaks/nulls are less audible than low Q.
*peaks are more audible than nulls
*Use low Q EQ in the higher frequencies.
*Shape the response with crossovers before EQ, don't be afraid to use assymetrical xover settings between L/R.


Sent from my iPhone 6 using Tapatalk.


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## SkizeR (Apr 19, 2011)

Hanatsu said:


> *Never boost in a non-minimum phase region.


aka, crossover regions? why is this?



Hanatsu said:


> *Use low Q EQ in the higher frequencies.


why this too? just trying to figure out if theres something deeper to it than it seems

Sent from my iPhone 6 using Tapatalk.[/QUOTE]


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## Niick (Jun 3, 2015)

SkizeR, sorry it took so long, been real busy that last couple days. 

Of course, yes, you pretty much always want to measure one channel at a time, UNLESS you're talking about the midbass to subwoofer transition. 

Anyways, here is two different smoothings of correlated vs. uncorrelated both channels driven


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## sqnut (Dec 24, 2009)

I agree with most of what you're saying, with a few exceptions.



Hanatsu said:


> Rule of thumb;
> 
> *Rather cut than boost. Agreed, you don't need to boost anything.
> *Never boost in a non-minimum phase region. ...but it's ok to cut here
> ...


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## Hanatsu (Nov 9, 2010)

SkizeR said:


> aka, crossover regions? why is this?
> 
> 
> 
> ...


[/QUOTE]


Minimum phase regions are regions where the response will respond well to EQ. It can be seen looking at excess group delay. Any flat region is fine to EQ. The peaks in in EGD correspond to dips in the FR, i.e destructive interference. This can't be fixed with EQ, boosting here will only increase distortion. True that a lot of crossovers do not inhibit minimum phase behavior, there are exceptions. This is the least of the issues while correcting the response in a car though. Swap the phase of one driver and it will show up in the EGD plot around crossover region, that sort of issues are the only ones you can show concern...

The EGD plot is only valid in one point in space, the higher in frequency we go the shorter the wavelengths are. Move the mic an inch and the response will differ, it gets worse with higher frequencies. That's why high Q EQ filters generally can't be used in higher frequencies. You either have to use smoothing or spatial averaging to get a somewhat representation of what we hear.


Sent from my iPhone 6 using Tapatalk.


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## Hanatsu (Nov 9, 2010)

GEQ isn't what I would call high Q. That's about the limit of high you should go in the high frequencies.

What I meant by assymetric was that you don't need the same electrical crossover settings left and right side. Get the sides as close to eachother with the crossover settings before EQ is a better way of doing it imo.


Sent from my iPhone 6 using Tapatalk.


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## sqnut (Dec 24, 2009)

Imho asymmetric L/R xover points/slopes just messes with the imaging and requires a lot more work on the eq and it still doesn't feel right. A 31 band eq per driver is more than enough eq to sort out any response issues. The only time I would consider using asymmetric would be if I only had like 5-7 bands of eq, of course ymmv.


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## percy072 (Feb 13, 2014)

wow...I mean WOW!! I cannot believe the difference making those cuts from 160-300hz made! I also realized I needed to bottom out everything from 20-50hz on the mid EQ (duh). That got rid of most of the muddied bottom end. 

For the short couple years I've gotten into car audio...it always felt like a chore, nothing was ever really coming together. Kept going through driver's like water, amps, all that money spent and was never really impressed till this point! Feels like a weight has been lifted!!

To bad I've nearly floored alot of the eq bands not leaving much padding for tweaking...but as it is now I am finally very "impressed"!! Thanks a ton guys for your patience and help on this (sicride, Hanatsu) and others...you've made a WORLD of difference 

This is a smoothed version of everything playing (pink noise)... Left mid and right tweeter still a little messed up but I will continue to tweak over time.


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## sicride (Oct 26, 2014)

Glad to hear that Aha! moment has come for you. It is a hobby changing moment, nothing shy of this sound will satisfy you again.  Nice work by the way, looks so much better.


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## percy072 (Feb 13, 2014)

Thought I'd show pics of the Sound manager for the H-800 settings for both EQ and PEQ (if it helps) Alot of cuts, you can see that nuisance 600hz peak its bottomed on the PEQ


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## trumpet (Nov 14, 2010)

percy072 said:


> This is a smoothed version of everything playing (pink noise)... Left mid and right tweeter still a little messed up but I will continue to tweak over time.



Can you make separate left and right full bandwidth measurements and plot those graphs together? This will show us how the adjacent drivers are combining at the crossing regions, which are currently showing as big dips on this image.


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## sicride (Oct 26, 2014)

Cool, those helped a lot. There's still a lot of room for improvement. I'm guessing the alpine unit uses both the parametric and graphic eq's at the same time so they are combining? Look at your left side graphic eq, every band is cut, some maxed out and you don't have the shape you want. If your raise every one of those bands so that the least cut band is now at 0 it will give you more oomph and more eq power on the trouble bands. Also you may be able to stack bands of eq in the parametric area, so bands like the 600hz could use slightly more cutting take the next band over which is unused and change it as close as possible to 600 to make more cuts.

Also your right tweeter has way too many cuts in the 2-4k range and that's why it looks like cap there. Might want to change both of the tweeter crossovers to 24db and maybe move them both up to 3k.


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## percy072 (Feb 13, 2014)

trumpet said:


> Can you make separate left and right full bandwidth measurements and plot those graphs together?


Not a full bandwidth but this is the response curve of left + right mid's...peak city on the left mid.



This is an un-eq'd full bandwidth response. 





sicride said:


> your right tweeter has way too many cuts in the 2-4k range and that's why it looks like cap there. Might want to change both of the tweeter crossovers to 24db and maybe move them both up to 3k.


I did use the Parametric with a high Q and cut that 600hz (580hz close as can get) peak to max as well as on the GEQ...but I think I know what your suggesting.

I cut alot on 2-7khz region because I kept seeing a big upswing peaking at 4khz on the right mid? You can still see some of that peak. That is one thing about the H-800 is that is does not allow full tuning per driver. Sub, each rear and L and R tuning but only within the same Parametric and Graphic EQ's, no separate tuning on either midbass only or tweeter only. 

Before I made those cut's I also had and peak from 4-7khz and the response looked more "dome" like. Right tweeter and Left mid do not really like to move much. Right tweeter only seemed to start responding @ 4khz so I kept lowering the crossover in attempt to get a lower freq. response...trying to force a lower response. I will keep working on it (esp. left mid and right tweeter). So far it's the best it's sounded yet, but done tuning for today...ran out of patience :blush:


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## Hanatsu (Nov 9, 2010)

Here's some measurements of one of my current builds. The wonders of an EQ with 4096 taps per channel. Yes - That is the same smoothing in both plots.



Here's a test of correlated vs uncorrelated noise on a full system. (Another system)



Here you can see how a system without any EQ compares in the time domain against a system with the corrections in place. The delay below 60Hz are due to the group delay of a vented box. The system requires about 15ms delay in order to attain good time coherency. 





That proves how much EQ affec


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## sicride (Oct 26, 2014)

Well if it doesn't let you eq the left tweeter independent of the left mid, then I wouldn't bother measuring them separate anymore. That is what trumpet and I are asking for lately. To play both left mid and tweeter together and measure that. Then right mid and tweeter together and measure that. Time to see how the drivers are interacting. In addition to how they are behaving individually.

Also if the left speakers are all tied together and you're trying to attenuate a mid past the crossover without eq'ing the tweeter, lower the mids low pass crossover. It is OK for the mid crossover and the tweeter crossover to be at different frequencies as long as the response is shaped properly when they play together.


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## Hanatsu (Nov 9, 2010)

Here's how the filter applied phase correction between L/R. This is my computer system.









Corrected response:


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## sicride (Oct 26, 2014)

That reminds me of how Dirac room correction seems to work. Looks like a really cool setup, sounds like it's pretty complex and REALLY expensive. You have to get the APL1 plus the computer program seperate plus a DSP like normal?


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## Hanatsu (Nov 9, 2010)

sicride said:


> That reminds me of how Dirac room correction seems to work. Looks like a really cool setup, sounds like it's pretty complex and REALLY expensive. You have to get the APL1 plus the computer program seperate plus a DSP like normal?


Not very complex to use... and yes you need all three. Possible to use as a VST for home audio too, so it got multiple purposes. This unit is an equalizer. If your install is somewhat good, you will get perfect staging and perfect tonality. I think it's worth it.


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## brumledb (Feb 2, 2015)

Hanatsu said:


> Not very complex to use... and yes you need all three. Possible to use as a VST for home audio too, so it got multiple purposes. This unit is an equalizer. If your install is somewhat good, you will get perfect staging and perfect tonality. I think it's worth it.



Does the ALP1 come before or after the DSP? Does it matter which is first?


Sent from my iPhone using Tapatalk


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## percy072 (Feb 13, 2014)

sicride said:


> play both left mid and tweeter together and measure that. Then right mid and tweeter together and measure that. Time to see how the drivers are interacting. In addition to how they are behaving individually.


Oh ok...I understand what your asking. I will do that and post the results this week.


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## Hanatsu (Nov 9, 2010)

brumledb said:


> Does the ALP1 come before or after the DSP? Does it matter which is first?
> 
> 
> Sent from my iPhone using Tapatalk


Yes it matters. It's a 2 channel EQ. Needs to be on the input side of the DSP, otherwise you need 4 units for a 8 channel system.


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## subterFUSE (Sep 21, 2009)

Here is my tune from 2015 Finals. These are individual driver measurements, with EQ + XOver applied. I don't think I have a combined response measurement but you can see the House Curve on this chart. The combined actually followed the House Curve even better because of the summation at the crossover points.

Red line is the house curve.

Subwoofer in light blue.

Midbass (Left & Right) are the purple lines.

Wideband drivers (Left & Right) are the other set of lines.


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## thebookfreak58 (Jun 18, 2012)

How did you overlay the house curve on your measurements? I can't seem to find how to do that in REW other than on the EQ tab.


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## Hanatsu (Nov 9, 2010)

subterFUSE said:


> Here is my tune from 2015 Finals. These are individual driver measurements, with EQ + XOver applied. I don't think I have a combined response measurement but you can see the House Curve on this chart. The combined actually followed the House Curve even better because of the summation at the crossover points.
> 
> Red line is the house curve.
> 
> ...


Looks great. Did you score good on the finals?


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## Hanatsu (Nov 9, 2010)

thebookfreak58 said:


> How did you overlay the house curve on your measurements? I can't seem to find how to do that in REW other than on the EQ tab.


Import frequency response from text, in the top left menu.


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## thebookfreak58 (Jun 18, 2012)

Hanatsu said:


> Import frequency response from text, in the top left menu.


Thanks


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## subterFUSE (Sep 21, 2009)

Hanatsu said:


> Import frequency response from text, in the top left menu.



what he said. ^


Sent from my iPhone using Tapatalk


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## Niick (Jun 3, 2015)

percy072 said:


> Thought I'd show pics of the Sound manager for the H-800 settings for both EQ and PEQ (if it helps) Alot of cuts, you can see that nuisance 600hz peak its bottomed on the PEQ


hang on! Is it possible to use the PEQ & GEQ SIMULTANEOUSLY on the H800???!!!


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## truckguy (Sep 2, 2013)

Sub, first thanks for being one of the few who compete at your level and willing to post their actual FR. Do you use this same curve for daily driving?


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## subterFUSE (Sep 21, 2009)

truckguy said:


> Do you use this same curve for daily driving?



Yes, it's the same. I don't have different tunes for competition vs. daily.


I'm about to start tuning for SBN this weekend, but I'm planning to use a different curve this time. Actually, I'm going to tune to maybe 3 or 4 different target curves and then spend some time doing A/B listening to decide which I prefer.


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## ssclassa60 (Jan 28, 2013)

truckguy said:


> Sub, first thanks for being one of the few who compete at your level and willing to post their actual FR. Do you use this same curve for daily driving?


Agreed, thanks sub... - competition level information regarding tuning is truly valuable to those who do not. It's actual validated information.


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## ssclassa60 (Jan 28, 2013)

Last night's retune trying out subturfuse's target curve with a touch more low end. I lowered my hpf chip to the midbass to around 70 (from 90) and lowered my lpf to the factory ib 10s to around 55Hz. I'm finding the phoenix gold dip chip calculations from the manual aren't very accurate....
SS Class A 3.0 is on the subs. Adcom 4304 on the rest. Analog 31band x2 eq.
Car is running causing low freq response around 40Hz.
There were a few nulls - 500Hz on one side, 2k and 4k on the other. Tried not to raise any sliders to more than +6. I have a few adjusted to -12.
I'm happy with the tonality - really nice. Staging is nice with a 40cm delay on the entire L side. 
Left midbass/neo8








Right side








Together








With subs


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## subterFUSE (Sep 21, 2009)

It's not "my" curve. I got it from Jazzi's tuning companion spreadsheet. It's the JBL Andy curve, if I remember correctly.


Sent from my iPhone using Tapatalk


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## ssclassa60 (Jan 28, 2013)

Fair enough sub, I thought it looked familiar 
My previous tune was almost identical except flat out to 10k and the midrange didn't flatten out until 250-300Hz


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## strohw (Jan 27, 2016)

subterFUSE said:


> It's not "my" curve. I got it from Jazzi's tuning companion spreadsheet. It's the JBL Andy curve, if I remember correctly.
> 
> 
> Sent from my iPhone using Tapatalk


I too thought it was a slightly modified JBL curve. Their curve is around -5db to 6db at 20k but you're curve hits it at 10k. Just assumed it was intended that way for your install.


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## subterFUSE (Sep 21, 2009)

strohw said:


> I too thought it was a slightly modified JBL curve. Their curve is around -5db to 6db at 20k but you're curve hits it at 10k. Just assumed it was intended that way for your install.


Hmmmm.... I don't remember editing it, but maybe I did. :laugh:


Regardless, I'm planning a little more bass heavy in the future.


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## oabeieo (Feb 22, 2015)

ssclassa60 said:


> Last night's retune trying out subturfuse's target curve with a touch more low end. I lowered my hpf chip to the midbass to around 70 (from 90) and lowered my lpf to the factory ib 10s to around 55Hz. I'm finding the phoenix gold dip chip calculations from the manual aren't very accurate....
> SS Class A 3.0 is on the subs. Adcom 4304 on the rest. Analog 31band x2 eq.
> Car is running causing low freq response around 40Hz.
> There were a few nulls - 500Hz on one side, 2k and 4k on the other. Tried not to raise any sliders to more than +6. I have a few adjusted to -12.
> ...


With a analog eq I wouldnt boost a thing. Maybe 20k and that's it . 

It will sound good with boost but only up to a point on the volume knob. 

If there's Nulls I would leave eq at 0 and ignore them or tune around them a little , like drop eq on adjacent bands to get it a db or two but for the most part the null isn't going away. 

Turn up system and knock those boosted areas down and let us know if it sounds better at higher volumes with them down. Should have a lot less distortion.


Often times it sounds better when the entire left side is set to the same delay setting, especially in the midbass range where wavelength is long. I like to do the same a lot and it does sound good.


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## ssclassa60 (Jan 28, 2013)

Thanks, I have done a bit a research here and acknowledge the 'don't boost nulls' concept and already have maxed out cutting around the 2k and 4k nulls. The null at 500Hz is the odd one - and I think verifies your point. When I crank it, it gets harsh, by my ears in the 500-630 range which also happen to both be set around +6/+4. 
I think I have room to raise the levels of the midbass channels and retune.
I'm at +4 at 4k as well...


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## sqnut (Dec 24, 2009)

ssclassa60 said:


> Thanks, I have done a bit a research here and acknowledge the 'don't boost nulls' concept and already have maxed out cutting around the 2k and 4k nulls. The null at 500Hz is the odd one - and I think verifies your point. When I crank it, it gets harsh, by my ears in the 500-630 range which also happen to both be set around +6/+4.
> I think I have room to raise the levels of the midbass channels and retune.
> I'm at +4 at 4k as well...


Can you post screen shots of your eq to go with your graphs?


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## subterFUSE (Sep 21, 2009)

I boosted dips on my tune, and it worked.

Most of my nulls were not the supposed "bottomless pits" of cancellation, at least based on the measurements. When I boosted a dip, it more likely than not got filled in nicely.


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## ssclassa60 (Jan 28, 2013)

sqnut said:


> Can you post screen shots of your eq to go with your graphs?



Sure, I appreciate the insight guys. Will go outside and take a pic in a minute.


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## strohw (Jan 27, 2016)

I have a usb mic so I can't measure anything that needs a loop back. For "nulls", I just dump +3db into it and run a sweep again. If I see roughly a 3db change then I guess don't consider it a null really. On the true nulls in my vehicle, if I were to bump them +6db I may only get a 1db to 1.5db change or less.


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## ssclassa60 (Jan 28, 2013)

strohw said:


> I have a usb mic so I can't measure anything that needs a loop back. For "nulls", I just dump +3db into it and run a sweep again. If I see roughly a 3db change then I guess don't consider it a null really. On the true nulls in my vehicle, if I were to bump them +6db I may only get a 1db to 1.5db change or less.



Yes I noticed this last night at 500, 2k, and 4k


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## ssclassa60 (Jan 28, 2013)

My eq, the 800Hz issue is related to L/R balance. 80Hz might be considered a null too. I thought cabin gain would be in effect at 80...
Also to note, my left midbass is reversed polarity to create proper phase response.


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## ssclassa60 (Jan 28, 2013)

Another view


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## Kazuhiro (Apr 28, 2015)

subterFUSE said:


> It's not "my" curve. I got it from Jazzi's tuning companion spreadsheet. It's the JBL Andy curve, if I remember correctly.
> 
> 
> Sent from my iPhone using Tapatalk


Overall, why did you pick this curve among the bunch? 
Preference/Performance/Tonality wise


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## sicride (Oct 26, 2014)

Ssclassa60: may be worth trying a reduction of 3 dB each side at 63 and 80hz. It should still be reasonably smooth without the added risk and distortion. Although your 20k region is weak, are you capable of hearing that high with accuracy? If you put those both back to 0 do you actually hear a difference? It still seems rather risky to boost that region for little to no gain. If it clips enough you could still damage your tweeters couldn't you?

I agree with oabeieo that any boost may not be necessary, if it responds to boosting and you can't cut to smooth things out or even things out, I still limit myself to 3 dB. Everybody's situation is different and as long as you know you're not clipping or don't care that you are, do as you please.


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## ssclassa60 (Jan 28, 2013)

Thanks, I definitely can't hear to 20k but my understanding is that the power required to produce 20k at high levels is very low, and would never be the cause of an amp clipping. Please correct me if I'm wrong.

I will try your suggestion at 63/80Hz. It just occurred to me that I might benefit from flipping the polarity of my subs as that is my crossover region... I'll try that first.


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## percy072 (Feb 13, 2014)

This is incredible... Kinda making me want to get my little Pioneer PRS midranges back in. 



subterFUSE said:


>





subterFUSE said:


> I boosted dips on my tune, and it worked. Most of my nulls were not the supposed "bottomless pits" of cancellation, at least based on the measurements. When I boosted a dip, it more likely than not got filled in nicely.


Was curious about this...I went back to "never boosting anything" and cut the hell out of peaks recently, but I have to admit it sounded better when I had some of the mega dips filled in a little more by boosting.

At some point one can at least try and "do what ya gotta do" to get a flatter response? As long as there is no distortion happening and it sounds better...?

I also tried to swap mids and (interestingly) had almost the same response curve I kept getting with my GZ Nuclear' mids  but the GZ's sound 10X's better.


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## oabeieo (Feb 22, 2015)

subterFUSE said:


> I boosted dips on my tune, and it worked.
> 
> Most of my nulls were not the supposed "bottomless pits" of cancellation, at least based on the measurements. When I boosted a dip, it more likely than not got filled in nicely.


And you can if it works out. Heck it never hurts to try. 

Can't argue with results either. 

I usually tune flat and ignore all rules I cut than boost and force a flat line. Than I go to all the boosted areas and tun each one down and see if makes sound better/worce. 

I have cancelation inside the throat of my horn at 12k and I boost with great results, so yes if it works out go for it .

But more than likely more than +3db in the midrange or midbass usually turns to mush after a couple db boost. But again yeah it usually works pretty good to squeeze a db or two out of a null. But +6db at high volumes ..... Eek ( probably sounds fine at lower level tho too )


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## oabeieo (Feb 22, 2015)

ssclassa60 said:


> My eq, the 800Hz issue is related to L/R balance. 80Hz might be considered a null too. I thought cabin gain would be in effect at 80...
> Also to note, my left midbass is reversed polarity to create proper phase response.


Sacrificing midbass for phase....

It's a hard decision to make, you must REALLY want the vocal nice and center to give up your midbass responce. 

By looks of your eq and that particular eq I would probably do some more with level setting between amps. And try get it down to where you aren't boosting anywhere under 5k more than 3db. If your midbass is reversed is definitely wouldn't add any boost to 80 or 100 or even up to 315. 

IMHO I would swap back you midbass and sacrifice imageing for spectrical balance. It will sound a lot better unless your dead set on that center image. And if you are maybe consider running your sub up to 125hz to help it . 

The sub will still sound good playing that high especially if it has a ID ring in it (faraday ring) or a sleeve or cap at a minimum. 

That will help out and make the compermise on sub localization for imaging. 


Cheers


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## subterFUSE (Sep 21, 2009)

Kazuhiro said:


> Overall, why did you pick this curve among the bunch?
> 
> Preference/Performance/Tonality wise



Eenie, meenie, miney, moe. 


Sent from my iPhone using Tapatalk


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## Kazuhiro (Apr 28, 2015)

subterFUSE said:


> Eenie, meenie, miney, moe.
> 
> 
> Sent from my iPhone using Tapatalk


hehhee

You're not wrong, from a casual (non competitive) user standpoint I keep going back to the jbl/andy. Whitledge is great, especially for larger vehicles, and can produce a visceral experience, though it isn't as robust over all genres as much as andy. Also if you play some silly 20 - 30hz music you will rattle your car to pieces haha
I have tried both curves for trials over many months. 
Personally, I stick with a modified andy. My midbass region is inflated by a couple db for fun, and my 200 - 2k is not completely flat, it drops 3 - 5dB or so. The tweeter roll off is also steeper.


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## sicride (Oct 26, 2014)

Lol that sounds more like a Kazuhiro curve. Kinda sounds like the only things they have in common is there's more dB at low frequencies than high frequencies. Revolutionary!  

Better to have it your way than listen to someone else's curve because they said it was good right?


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## ssclassa60 (Jan 28, 2013)

oabeieo said:


> Sacrificing midbass for phase....
> 
> It's a hard decision to make, you must REALLY want the vocal nice and center to give up your midbass responce.
> 
> ...


Thanks for the insight. Honestly I can't explain my issues at 63-80 on the midbass. I've run them in and out of phase with surprisingly no dramatic effect. Also note that I have very good response at R160Hz (-12) and L200Hz (-8). All I can point to are the sealed enclosures of have them in. I repurposed the stock BMW molded door enclosures and maybe my TM65's are being choked? I would guess their volume is in the 1-2liter range. I've heard of people getting great response down to 40Hz with the TM65's in a true IB configuration. 
As far as phasing, image is most important to me.
As far as amp gain adjustments, you can see each channel has at least one band at -11/-12db (L 2.5k / R 2k) so I feel I've optimized that. The fact that the difference in response at 2k L to R is around 18dB make my head spin a little. I'm definitely dealing with some comb filtering so it kind of is what it is (the Neo8's fire right into the windshield, shoved all the way to the junction). 

Again thanks for all of the feedback, my plan now is to tune by ear around my null points. I think bringing the null area sliders down a few dB's will help. To be honest, it sounds pretty darn good - but as mentioned, gets a little harsh when cranked. Raising the midbass gain and readjusting will be my next approach.


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## Kazuhiro (Apr 28, 2015)

sicride said:


> Lol that sounds more like a Kazuhiro curve. Kinda sounds like the only things they have in common is there's more dB at low frequencies than high frequencies. Revolutionary!
> 
> Better to have it your way than listen to someone else's curve because they said it was good right?


They're great starting points. Sometimes it's not just user preference, but system suited.


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## sicride (Oct 26, 2014)

Agreed, my Mustang requires a greater slope after 2k or it is fatiguing. 

While most people suggest tweeters as wide as possible, mine are in the sail panels but the dash is very high in those cars with hard large hard plastic trim and protruding air vents. Not to mention a very steep windshield and small cabin. I believe it is just too much reflection in that area. Should have put them in the a-pillars would have at least made for a more even and predictable reflective surface.

I have used same tweeters in a dash mounted up firing position which was not at all offense. It could also be that they are more on axis...


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## strohw (Jan 27, 2016)

What tweeters would those be


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## sicride (Oct 26, 2014)

Alpine SPX-13REF tweeters.


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## strohw (Jan 27, 2016)

I know what the problem is.

Your tweeters don't have enough characters in them. It's a proven fact that the more characters you put in a tweeters name the better it sounds. I'd aim for a set with at least 12 or more.


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## sicride (Oct 26, 2014)

You're probably right... at least as likely as what all I said.


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## mbradlawrence (Mar 25, 2013)

SkizeR said:


> ok this is strange. has anyone noticed this? i was messing around in the rta function and switched from spectrum to rta 1/12. same measurement, different results. like, 12db swing on the top end different


I was actually going to ask this question to see what folks were using. Was reading REW documentation and it said that spectrum measurement drops at 3db per octave while RTA does not. Thus, spectrum gives the downward curve and RTA should flat? Thoughts? Below is what I was referring to, from the REW manual:

Pink noise has energy that falls 3 dB with each doubling of frequency. On a spectrum plot it is a line that falls at that 3 dB per octave rate, on an RTA plot it is a horizontal line as the energy in the signal is falling at the same rate as the bins are widening. We perceive pink noise as having a uniform distribution of energy with frequency.


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## sqnut (Dec 24, 2009)

SSClass60,

The right way to tune your car is to physically sit in it and listen to whats going on. Since that is not possible, I'm going to go off your graphs and the eq the way it is set now. Based on your graphs, I'm trying to balance L/R better and smooth out the overall curve a bit. There is a set of people here who hate on me for doing this, but that's their problem not mine.

Note your current settings and then apply the settings given below to where ever you have the eq now. As I understand you have a sub plus two way front. Set the sub/mid xover at 60 and put the sub and mids on the steepest slope you can mange 24db/oct would be great. Keep the mid to tweet ~ 3khz again, matching slopes with no under/over lap.

20-50hz: Raise L&R to 0
63hz: cut R -2db
80hz: Cut L&R -4db
100hz: Raise L +2 and R +3
125hz: Cut L&R -2db
160-200hz: Cut L&R -1 db
250hz: Cut L -3 and R -2
315&400: Cut L&R -1db
500hz: Cut L -1 db 
600hz: Cut L -3 and R -2
800hz: Cut L&R -1.5~2 db
1khz: Cut L -2db cut R -1 db
1.25khz: Cut L&R -3 db
1.6 As is
2 khz: Cut R -1.5db
2.5khz & 3khz cut both sides -2 db
4khz: cut left -1db cut R -2db
5khz cut both sides -1 db
6 & 8 khz: Cut R -1.5db
10khz: raise both sides 2db
12.5khz: raise L +3 and R +2
16KHZ: L +1 R -1
20 khz: cut L&R -2 db

Take a listen and lets hear some feedback, measure again and lets see what you come up with.


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## Niick (Jun 3, 2015)

mbradlawrence said:


> I was actually going to ask this question to see what folks were using. Was reading REW documentation and it said that spectrum measurement drops at 3db per octave while RTA does not. Thus, spectrum gives the downward curve and RTA should flat? Thoughts? Below is what I was referring to, from the REW manual:
> 
> Pink noise has energy that falls 3 dB with each doubling of frequency. On a spectrum plot it is a line that falls at that 3 dB per octave rate, on an RTA plot it is a horizontal line as the energy in the signal is falling at the same rate as the bins are widening. We perceive pink noise as having a uniform distribution of energy with frequency.


in general the type of spectrum mode used in REW (as opposed to its fractional octave modes) is used for ELECTRICAL measurements, and the fractional octave mode is used for acoustic measurements. IN GENERAL


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## ssclassa60 (Jan 28, 2013)

sqnut-
Thank you for the advice - I will give it a shot and report back.
I have read your posts so please know I have a decent ear and a great 2.1 reference system at home. I agree that final tune should be done by ear.
My system is 3 way but with semi-wide band planars on my dash. My F3 on the sub to midbass is currently 60Hz but limited to 18lp/12hp. My midbass to wideband F3 is around 700Hz with the planars taking it all the way to 20k. Also note most of my L/R balance are due to adjustments made by ear to center each 1/3 octave band.
Let me know if this changes your advice.


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## sqnut (Dec 24, 2009)

ssclassa60 said:


> sqnut-
> Thank you for the advice - I will give it a shot and report back.
> I have read your posts so please know I have a decent ear and a great 2.1 reference system at home. I agree that final tune should be done by ear.
> My system is 3 way but with semi-wide band planars on my dash. My F3 on the sub to midbass is currently 60Hz but limited to 18lp/12hp. My midbass to wideband F3 is around 700Hz with the planars taking it all the way to 20k. Also note most of my L/R balance are due to adjustments made by ear to center each 1/3 octave band.
> Let me know if this changes your advice.


No prob, advice remains the same .


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## ssclassa60 (Jan 28, 2013)

Here ya go sq:

After change results below. I never mentioned my method of measurement. In car seat all the way back. Sample average of two right ear sweeps (front to rear 8") followed by 2 left ear sweeps plus a second in center. Proving very consistent.

Left midbass/neo8 (midbass took a hit)










Right side (midbass unaffected after changes)










Together










With Subs










Looks like the Crutchfield curve a little?

Listening to reference material, tonality and staging still very good (still 40cm delay on L ch). I noticed the increase in level at 3-400 and 31.5. More chesty and under the seat rumble. Also a bit brighter up top. I want to say it had a little more bite - but only an hour of listening so far. I used Dire Straits, Acoustic Alchemy, Tribe, and Doggystyle as ref


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## sqnut (Dec 24, 2009)

with a wide bander you may want to taper off the 10+ add on's that I recommended Those would be more appropriate with a reg tweet. Cut a bit more st 2.5 & 3. Yep, 300-400 can take a bit of a cut as well. Cut 80 a 2 more and move the sub LP to 40 hz on 18 db slopes this will lose the extra low end flab. Make these changes and listen. Is your sub sealed or ported? And yeah back off a bit at 30......Rome wasn't built in a day, we'll get there .


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## #1BigMike (Aug 17, 2014)

I love this forum... As long as you are willing to learn and ask for help, the forum members always come through IMO....


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## ssclassa60 (Jan 28, 2013)

sqnut said:


> with a wide bander you may want to taper off the 10+ add on's that I recommended Those would be more appropriate with a reg tweet. Cut a bit more st 2.5 & 3. Yep, 300-400 can take a bit of a cut as well. Cut 80 a 2 more and move the sub LP to 40 hz on 18 db slopes this will lose the extra low end flab. Make these changes and listen. Is your sub sealed or ported? And yeah back off a bit at 30......Rome wasn't built in a day, we'll get there .



My subs are IB and will be changing to old SS 10R's soon so I wont dwell. I think I have the lowest dip possible for my analog crossover which is 50Hz @18. Maybe there's a 350kohm, I'll check.

I'm will look at 315/400 and above 10k.
I'm at max cut on L ch at 2.5/3 but I think my head unit has a ****ty parametric 5 band...

Thanks


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## sqnut (Dec 24, 2009)

I think my post above was too brief and I didn't really explain anything, so I'm going to give some reasoning behind what I said. It must be said at the outset that what we are doing is a very approximate kind of way of doing things. There could be issues in measurements, resolution on rta, hence what I'm reading off it and my recommendations. So what I suggest as -3 at 400, should actually be -2. Let's assume for a minute that everything was perfect in stage 1 and I recommended -2, now when OP implements it there is another set of variables at play, visible resolution on eq, how op sets it and the cars response to the tweak. Just because we cut 4 db at 80 doesn't mean the measured response will fall 4 db. 

In my first post I had brought down 80hz by about 4db because it was way hotter than 100. So I cut 80 and brought 100 up. 100 hz responded but 80, not so much. Which is why I recommended cutting some more here and moved the LP on the sub. Remember we're getting a ton of cabin gain around here. 

While the process is approximate, what really helps here is that the OP has trained ears. So we had the earlier measurements --> recommendations --> implementation --> cars respone --> new measurements. So somethings worked according to plan and somethings didn't and we have peaks at different areas now. So now we have 300-400 a touch hotter than what's around it and SSClass is hearing this correctly as chesty vocals. Also 1, 1.6, 2.5 and 3 now stand out in what looks like 1-1.5db peaks in what is our most sensitive zone. Multiple small peaks in the 1.5-4khz zone will make the sound tinny and with too much bite......I think SS is being polite while qualifying the sound as having a touch too much bite. 

TLDR: Tuning on the internet is a slow and approximate process and it helps if you have trained ears to verify results.


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## sqnut (Dec 24, 2009)

ssclassa60 said:


> I'm at max cut on L ch at 2.5/3 but I think my head unit has a ****ty parametric 5 band...
> 
> Thanks


For sure, use the hu PEQ if you're maxed out on the analog eq.


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## ssclassa60 (Jan 28, 2013)

Maybe being a little polite regarding 'bite' 
Funny thing is, I could see how someone else might prefer that sound. It surely sounds more dynamic, exciting, impressive, ect... That's where it comes down to personal taste.
Without a solid reference to compare to, I might not even see it as color. 
What I'm loving about being able to tune, measure, and listen, is that I'm experiencing first hand how subtle response changes in certain areas impact my listening experience. When I was in the game before (early nineties) RTA's were a luxury item, everything was done by ear or a radio shack meter.


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## sicride (Oct 26, 2014)

By the way looking at sqnut's recommendations and your graphs, it looks like everything he told you to cut is higher on the right side than the left, so maybe start by cutting just the right side and rechecking. It may not only help with imaging but even out your overall tonality.


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## sqnut (Dec 24, 2009)

ssclassa60 said:


> Maybe being a little polite regarding 'bite'
> Funny thing is, I could see how someone else might prefer that sound. It surely sounds more dynamic, exciting, impressive, ect... That's where it comes down to personal taste.
> Without a solid reference to compare to, I might not even see it as color.
> What I'm loving about being able to tune, measure, and listen, is that I'm experiencing first hand how subtle response changes in certain areas impact my listening experience. *When I was in the game before (early nineties) RTA's were a luxury item, everything was done by ear or a radio shack meter.*


There are still guys around (including my mentor) who always finish 1-2 at finals when they compete and all they use is a RS meter. If you have a solid reference in your head, it is always better to tune towards that and to stay true to it, because that _is_ the right sound. 

If it is more dynamic but at the cost of extra bite, then you need to figure out which changes gave you the extra dynamics and which are contributing to the extra bite and hence need to be dialed back a bit. If you tweak a bit, try making a mental note of what changes in the sound at each frequency. If you do this for a bit, you will start to build a solid correlation between what you're hearing and hence, where (frequency) and how (+/-) you need to correct. Its a slow and frustrating process and only the marginally OCD types keep going to the point where correlation begins to fall into place and they get more intuitive with the eq. 

You make a great point about having a solid reference. It is vitally important to hear a difference between the ref sound and the sound in the cars. If we're only hearing a nominal difference between the two, then we should either be winning championships (No one is going to go through that much of pain and frustration and not want to showcase their tune), or we need to listen more closely. You're spot on with that.

The point of having a ref sound means that most listening sessions should be an experience. If the ears are fresh and one closes the eyes and listens to familiar, well recorded content, I find myself walking away from the session slightly punch drunk. There is an aural experience which includes balance, tonality and timbre, this gives us the sense of natural and real sound. We get visual cues even with our eyes shut because it's there on the recording. Listening is also a physical experience, because when we hear sound the way it was recorded, the whole body seems to relax and the mind is calmer. That is the experience one is trying to recreate in the car. 

An RTA is a nifty tool to have while building the correlation between how it measures and what we're hearing, but eventually one will reach a point where it measures good but still doesn't sound right. If you'd like to try another experiment, try and qualify the things you would like to improve vs your ref sound and let's see if we can find them on your graphs and the possible solutions.


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## ssclassa60 (Jan 28, 2013)

Good insight sq

I should have expanded on my statement about enjoying the tuning process. You hit it exactly on the head - after every tuning session, I walk away with a better correlation between boost/cut at a particular frequency, and the effect on my perceived tonality. I've learned my ear is most sensitive to 2-2.5k. Boost here is where I think I hear 'bite' but I'm still experimenting to confirm this. The dynamic improvement I currently have I think is due to the brighter top end. My planars have amazing quick response/decay specs and I think the boost on the top end highlights this. Again, still too early to say for sure. 

I love this hobby (and home hifi) because I love music. Lately I walk away from a reference material session in my car with a huge grin on my face. And that's what it's all about to me  Trying to recreate the giddiness I get after leaving a well mixed live performance.

I will continue to post as I make progress with my measurement/listening correlations and my overall tune.


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## sqnut (Dec 24, 2009)

The bite is from the small peaks in the mid range and the dynamics come from better balance a more open top end is certainly a part of it as is our changes at 80-100, cutting bloat at 200-250 and tempering the 500-1.25 khz range a bit.TBH though I should have tapered off opening the top end once you told me you were running wide banders.


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## oabeieo (Feb 22, 2015)

ssclassa60 said:


> Thanks for the insight. Honestly I can't explain my issues at 63-80 on the midbass. I've run them in and out of phase with surprisingly no dramatic effect. Also note that I have very good response at R160Hz (-12) and L200Hz (-8). All I can point to are the sealed enclosures of have them in. I repurposed the stock BMW molded door enclosures and maybe my TM65's are being choked? I would guess their volume is in the 1-2liter range. I've heard of people getting great response down to 40Hz with the TM65's in a true IB configuration.
> As far as phasing, image is most important to me.
> As far as amp gain adjustments, you can see each channel has at least one band at -11/-12db (L 2.5k / R 2k) so I feel I've optimized that. The fact that the difference in response at 2k L to R is around 18dB make my head spin a little. I'm definitely dealing with some comb filtering so it kind of is what it is (the Neo8's fire right into the windshield, shoved all the way to the junction).
> 
> Again thanks for all of the feedback, my plan now is to tune by ear around my null points. I think bringing the null area sliders down a few dB's will help. To be honest, it sounds pretty darn good - but as mentioned, gets a little harsh when cranked. Raising the midbass gain and readjusting will be my next approach.


That sounds like pattern flip. 

Somethings horn loading if you ask me . Not certian but has the recipe for it.

Usually when one side of car has a drop in responce and a boost in responce in eq slider right next to it , and the other side of the car is OPPOSITE. That indicates a pattern flip. Associated with there mounting location and where your measureing from. 

I have pattern flip on my dash pods at 630-800 I learned to live with it , eq around it a tad but can definitely hear it on certain songs where one side gets loud just at one frequency like on the side of the speakers location. Lol


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## ssclassa60 (Jan 28, 2013)

oabeieo said:


> That sounds like pattern flip.
> 
> 
> 
> ...



Interesting point. I am stuck with my midbasses halfway up the door firing directly at each other. I'm seeing a little pattern flip as you've described it, in octave relationships, 125, 250, and 500. You could also argue 63 (another multiplier) and 800 (lp xover point). I'm guessing if I ran them up to 1k, we'd see it again there.

Again, The left midbass is wired reverse polarity for proper phase response. This might contribute, at least to the fundamental frequency of this behavior. It sounds good with eq so I will leave it

The only other area I have this flipped effect is at 2k, and it's drastic.

Back to listening/tuning experiments, I've been trying to identify what frequencies correlate with 'dynamic' (good) and 'bite' (bad).
I think I've found them and correlated my findings against the measured response of my reference system using the same tools.
I found a slight increase in the 800-1.3k range translates into a dynamic sound by my ears, and just next door, an increase at 2k-3k sounds harsh and creates fatigue quickly. 
I came to these conclusions before i measured my home system and guess what? It measured about 3db low at 2k compared to 800 and 4k. Basically a 3-4db notch centered around 2.5k. 

I've used my parametric (hu) to tune by ear and ended up reducing 2.7k 2 clicks (3-4db) and raised 1.3k by 1 click. I want to go back and try raising 800-1k instead as 1.3k can sound a little rough depending on the listening material.

Will post rta plots soon.


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## sqnut (Dec 24, 2009)

Instead of raising 800-1.25 khz for better dynamics, just try 500 and 1khz. Too much of 1.25 and the sound will get grainy very quickly. 800 is good for vocal presence but too much and it can start honking like like the sound from an alarm clock radio. The bite is from 1.6-2.5 as you have correctly identified. Don't think about pattern flip, that's a horn related terminology and you aren't running horns. I'm not a fan of reversing polarity, specially if you have TA and eq. Try putting both mid bass in normal polarity and see if the dip at 500 goes away, or at least gets reduced


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## oabeieo (Feb 22, 2015)

sqnut said:


> Instead of raising 800-1.25 khz for better dynamics, just try 500 and 1khz. Too much of 1.25 and the sound will get grainy very quickly. 800 is good for vocal presence but too much and it can start honking like like the sound from an alarm clock radio. The bite is from 1.6-2.5 as you have correctly identified. Don't think about pattern flip, that's a horn related terminology and you aren't running horns. I'm not a fan of reversing polarity, specially if you have TA and eq. Try putting both mid bass in normal polarity and see if the dip at 500 goes away, or at least gets reduced


And your right sq, he isn't t running horns and that is the effect of a horn.

However, his speaker somewhere could be horn loading and the car interior is acting like the waveguide (at certian passbands only of course)

But again, more likely is something else, 

I had pattern flip on my 6.5" mids in my a pillars at 630-800 because the windshield and side glass was acting like the horn at those frequencies.

Patrick verified it as well and told me take some measurements and he was spot on the measurements. Spooky right. 

Well he ended up being right, after I listened to what was going on like you even reccomend, I could finally hear it for myself.

What's wierd is at a frequency that is lower/longer than the size of cone all adjacent surfaces help load ( or horn load) the driver. 

It's like putting a sub in the corner loads it against the wall right , well it's horn loading, just a funny shaped horn that looks a lot like the corner of your living room or what not either way it's horn loading. And there will always be two peaks when it's horn loading of it is further than a oactave. (I read that part haven't personally experienced that part yet) I usually start into eq before I anylize what's going on accousticly. Now I measure in/out of the car so I know what the car is doing for myself. Than I look at the data in REW and make sure it is consistent with my gut feelings. 

Either way, it was just a hunch and by no means was I saying that it was for sure a pattern flip. He would have to discover that for himself. 

How ya been man


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## oabeieo (Feb 22, 2015)

ssclassa60 said:


> Interesting point. I am stuck with my midbasses halfway up the door firing directly at each other. I'm seeing a little pattern flip as you've described it, in octave relationships, 125, 250, and 500. You could also argue 63 (another multiplier) and 800 (lp xover point). I'm guessing if I ran them up to 1k, we'd see it again there.
> 
> Again, The left midbass is wired reverse polarity for proper phase response. This might contribute, at least to the fundamental frequency of this behavior. It sounds good with eq so I will leave it
> 
> ...



Yeah, sq is really helpful , he know a lot about smoothing responce and I think he won't lead you down the wrong path.

On the flip side, it is possible to have a smooth responce and have phase issues/loading issues. 

I definitely don't want to try to tell you that it is fixable. IT IS NOT!

Well at least most of it isn't . We can only fix what out tools let us and the location/install allows. 

At some point your going to have to settle and learn to live with the compermises.


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## fcarpio (Apr 29, 2008)

subterFUSE said:


> Here is my tune from 2015 Finals. These are individual driver measurements, with EQ + XOver applied. I don't think I have a combined response measurement but you can see the House Curve on this chart. The combined actually followed the House Curve even better because of the summation at the crossover points.
> 
> Red line is the house curve.
> 
> ...


That is tight. I would love to see the full sweep.

Edit: How did you draw the house curve?


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## subterFUSE (Sep 21, 2009)

fcarpio said:


> That is tight. I would love to see the full sweep.


I think I still have the REW mdat files. I'll check on them and see if there's a full range sweep.




> Edit: How did you draw the house curve?


Jazzi's tuning companion spreadsheet can export the text file for the curve.
Then you import it as a frequency response and just view it in overlays like another measurement.


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## fcarpio (Apr 29, 2008)

subterFUSE said:


> Jazzi's tuning companion spreadsheet can export the text file for the curve.
> Then you import it as a frequency response and just view it in overlays like another measurement.


I think I found how to create one from scratch.

House Curve Preferences

If any of you have a house curve you would like to share it will be awesome if you copy and paste it here.


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## ssclassa60 (Jan 28, 2013)

Just to followup, here's my home reference, B&W powered by Adcom (12V) and servo Mirage 12" sub. Preamp is NAD. I need to raise the lowpass filter haha!


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## sicride (Oct 26, 2014)

That looks like fun for home except that suckout at 40-50hz. Is that your crossover region? Kinda low but it looks like a potential phase issue. 

You can see that the top end is a lot flatter than most car audio measurements which makes sense for a larger room. Looks like a lot of bass!


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## ssclassa60 (Jan 28, 2013)

Good call, I'll flip the phase switch and re-measure. My crossover is in the 40 range so it can disappear...
I'm curious if other home systems have this slope to around +9 moving down from 200? The system sounds tonally correct even compared to my reference headphones.


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## percy072 (Feb 13, 2014)

3-way...YO 

Thought I'd dig the hole a little deeper, but I just HAD to use my Pioneer midranges. They are up in the corners of the A-pillars (waiting for my pillar pods from Germany) tweeters stock location just in front of door handle, midbass' stock location. 

Using PEQ (much better) and really like it so far but still bit of "bark" with male vocals...and some sibilance at higher volumes. I think the GZ uranium tweeters are inherently peaky and their day's are numbered

Anyhoo...





Sub is unpredictable...blends well for most of what I listen to but looses it's mind on bass heavy music, constantly reaching for the RUX to control it (getting annoying)


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## ssclassa60 (Jan 28, 2013)

Nice curve  
Looks like there might be phase issues between sub/midbass and midbass/mid. You have dips at your crossover points where they should be summing...
Flip the polarity on your midbasses only (or use a 180 phase switch if available) and re-measure


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## percy072 (Feb 13, 2014)

ssclassa60 said:


> You have dips at your crossover points where they should be summing...


Yeah...not sure what's going on there?? My midbass/midrange X-over's on the DSP are actually set at 900hz/1000hz but the midbass drops off at 400 (ish) and the midranges pick up around the same point which is way below what I've actually put them at 

The sub has gotten wierd, unpredictable? Another one to add to the "WTF" list...har


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## sicride (Oct 26, 2014)

I could see a phase issue doing that when crossed that low. A lot of the "sub bass" we perceive is actually in the 60-80hz range. So having a suck out there means some songs will have lots of power and songs with bass in the 70hz range will sound dead obviously. I also wonder if you're having that same gain issue again on the midbass, still looks too strong below 150hz.

Also keep in mind the number you put into the DSP really means nothing, it's the effect it has on the sound/measurement that matters. So just try to remain flexible and it looks like you have been.

Might try flipping the the tweeters to phase also, or at least raising its level a few dB. I imagine this is getting fun, you've had a lot of drivers to play with lately.


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## percy072 (Feb 13, 2014)

I've still got room to make cuts below 150hz, when I lower the gains more...everything drop's in proportion. I seem to always have those high peaks at 90hz-300hz, then falls way off. I have to slam 160-300hz to "clean up" that area. 

I think I can snapshot the PEQ setting's on the DSP, still trying to figure that out but it's odd how much I have to cut...not boosting anything anymore though.


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## percy072 (Feb 13, 2014)

sicride said:


> I imagine this is getting fun, you've had a lot of drivers to play with lately.


It is fun, interesting and eff'n infuriating. Ever since I got the garage insulated and heated...I've been taking advantage of that. 

Got a little collection of drivers only because I kept making the classic mistake of trying to solve a "sound issue" by replacing and not making the investment in a good DSP, REW and start learning how to tune...but I still like trying new speakers


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## Hanatsu (Nov 9, 2010)

It's easy to see if you got interference between drivers to watch the individual measurements and the measurement where the drivers play together. The full system measurement should sum, i.e the SPL should be higher than the individual measurements around the crossovers. If you got a null, then one or more drivers are out of phase with eachother.

I just tuned my new car, about done with it. Pretty pleased with the results. Tonality is neutral with good bass fundamentals. Staging is almost as good as it can be in this setup, I need to do a few more correction below 100Hz for optimal sub integration...


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## percy072 (Feb 13, 2014)

I'm just gonna have to admit that I really have no idea about what it mean's or how to address it when someone talks about drivers are/could be "out of phase"??

I understand that there is electrical phase (polarity) and acoustic phase. 

What...do I do? (said like Captain Kirk)


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## Hanatsu (Nov 9, 2010)

percy072 said:


> I'm just gonna have to admit that I really have no idea about what it mean's or how to address it when someone talks about drivers are/could be "out of phase"??
> 
> I understand that there is electrical phase (polarity) and acoustic phase.
> 
> What...do I do? (said like Captain Kirk)


Yes...

T/A is your best bet, it will alter the relative phase between drivers (changing crossover type/slopes will also do this). If you got a cancellation add or remove delay to one of the drivers and hopefully it will go away.

In the lower frequencies the wavelengths will be very long and therefore you need to add quite a bit of T/A to see any real changes.


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## sicride (Oct 26, 2014)

According to the h800 manual on the xover screen there's an option for phase 0 and 180. Because this is in the processor not actually flipping the speaker leads I believe adjusts the acoustical phase 180 degrees but it is basically the same result. 

Hanatsu probably sees something I don't though if he's suggesting T/A or xover adjustments. I have found especially when using different xover slopes per driver I end up with phase issues, so I try to match them both 24 dB or both 12 dB etc. All you can really do is play around, if you use RTA with pink noise and little to no averages you can probably make these adjustments in real time and get results instead of trying to get full spatial averages each time.


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## ssclassa60 (Jan 28, 2013)

Hanatsu said:


> It's easy to see if you got interference between drivers to watch the individual measurements and the measurement where the drivers play together. The full system measurement should sum, i.e the SPL should be higher than the individual measurements around the crossovers. If you got a null, then one or more drivers are out of phase with eachother.
> 
> I just tuned my new car, about done with it. Pretty pleased with the results. Tonality is neutral with good bass fundamentals. Staging is almost as good as it can be in this setup, I need to do a few more correction below 100Hz for optimal sub integration...



Thanks for the reference curve. You're using APL1 correct?


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## davewpy (Jun 22, 2014)

sicride said:


> According to the h800 manual on the xover screen there's an option for phase 0 and 180. Because this is in the processor not actually flipping the speaker leads I believe adjusts the acoustical phase 180 degrees but it is basically the same result.
> 
> Hanatsu probably sees something I don't though if he's suggesting T/A or xover adjustments. I have found especially when using different xover slopes per driver I end up with phase issues, so I try to match them both 24 dB or both 12 dB etc. All you can really do is play around, if you use RTA with pink noise and little to no averages you can probably make these adjustments in real time and get results instead of trying to get full spatial averages each time.


If I had to match a 2nd order HPF to a 3rd order LPF, I might try one of the following;
1. Add a 90° phase shift on the first.
2. Add a 180° phase shift on the first and a 90° shift on the 2nd.

Just sharing... Not sure whether this is right or not, but it sounds right by me and I believe this solves GD at the electrical stage.

Sent from my ONE A2005 using Tapatalk


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## ssclassa60 (Jan 28, 2013)

sicride said:


> According to the h800 manual on the xover screen there's an option for phase 0 and 180. Because this is in the processor not actually flipping the speaker leads I believe adjusts the acoustical phase 180 degrees but it is basically the same result.
> 
> Hanatsu probably sees something I don't though if he's suggesting T/A or xover adjustments. I have found especially when using different xover slopes per driver I end up with phase issues, so I try to match them both 24 dB or both 12 dB etc. All you can really do is play around, if you use RTA with pink noise and little to no averages you can probably make these adjustments in real time and get results instead of trying to get full spatial averages each time.


Yes the effect is similar but electrically it they are different. Flipping polarity causes a positive signal voltage to move the speaker backwards towards the magnet. It is now mechanically out of phase (180deg) with a speaker wired the proper way. If you've ever screwed up sub wiring in a shared enclosure, the net effect is zero output as they cancel each other out.

Phase effects from processors are different as they offset or shift or delay the signal 90deg per 6db filter slope. A 48db filter is acoustically the same as a 24db as they both end up back at zero. I thought this is why old school crossovers had 18db low pass and 12db highpass slopes. To give a little acoustic separation of the signals and more to play with than polarity.

If you flip the phase offset switch on 1 sub in a shared enclosure, you still get some output but it sounds very bad


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## calebkhill (Jan 12, 2013)

subterFUSE said:


> Here is my tune from 2015 Finals. These are individual driver measurements, with EQ + XOver applied. I don't think I have a combined response measurement but you can see the House Curve on this chart. The combined actually followed the House Curve even better because of the summation at the crossover points.
> 
> Red line is the house curve.
> 
> ...


You must have edited the curve txt file to start around your listening level.


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## Hanatsu (Nov 9, 2010)

No. You can offset it in RoomEQ


Sent from my iPhone 6 using Tapatalk.


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## calebkhill (Jan 12, 2013)

Hanatsu said:


> No. You can offset it in RoomEQ
> 
> 
> Sent from my iPhone 6 using Tapatalk.


Ah. How so?


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## subterFUSE (Sep 21, 2009)

Hanatsu said:


> No. You can offset it in RoomEQ
> 
> 
> Sent from my iPhone 6 using Tapatalk.




Yup. It's called Target Level in the EQ window. Start with your quietest driver, set the Target Level to align the House Curve to your measured response and then use the same level for all other drivers.


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## Hanatsu (Nov 9, 2010)

You can also offset in spl tab options top right corner.


Sent from my iPhone 6 using Tapatalk.


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## swyner (Oct 24, 2015)

Hey all. Loving this thread!!!! I am a super NOOB to this tuning hobby but definitely want to get into it. I have an Alpine H800 and have done some of the auto TA/imprint only to be dissatisfied with the results. I started reading a lot on these forums and decided that I wanted to "get in the game". For other NOOBs like me, is there a quick "must have tools" and good starting point so we can not feel so overwhelmed? I have done a lot of research and as far as I can tell, the basic tools are as follows:
1) Processor (duh) - I have Alpine H800
2) REW software
3) USB Mic (or SPL meter) but minimum is USB mic
4) Laptop (I have Surface 3)
5) Other connections (like 3.5MM to RCA L/R to plug Surface 3 direct to PXA)

Once we have all this, would a good starting place be to remove all EQing, TA, basically setup the PXA so that each driver is just operating at a "non tuned" state? Then step 2 would be to get some testing done of each driver INDEPENDENTLY using REW? Is this the time you place the mic where you want your listening position? Do you hold it static or do you move it from ear to ear? What settings in REW do you use? Pink noise?

Anyway, I know most on this forum are more seasoned at this than I am so forgive my simple questions....would love to get into this and just need a good place to start.
Thanks all


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## Kazuhiro (Apr 28, 2015)

The stickied articles in here should get you going;

How-To Articles Provided by our members - Car Audio | DiyMobileAudio.com | Car Stereo Forum


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## swyner (Oct 24, 2015)

Thanks for the direction to the stickies....was reading a lot and trying to absorb...a couple of common questions that come up that seem to never really get answered (probably because there is no "right" answer) but should one perform T/A on all the channels BEFORE or AFTER you start all your measurements, EQing, etc??? Also, now that REW has the ability to do T/A with the USB mic, has anyone confirmed this works well? If so, anyone have good step by step? Getting my mic on Friday so will be tinkering with this soon!!!


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## strohw (Jan 27, 2016)

You can rough in the T/A by measurement first if you want. I would suggest using HolmImpulse for T/A instead of REW.

The Subwoofer DIY Page v1.1 - Time Alignment using HolmImpulse


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## swyner (Oct 24, 2015)

strohw said:


> You can rough in the T/A by measurement first if you want. I would suggest using HolmImpulse for T/A instead of REW.
> 
> The Subwoofer DIY Page v1.1 - Time Alignment using HolmImpulse


Awesome...will be a great place to start. Thanks!


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## subterFUSE (Sep 21, 2009)

Reading an Impulse Response is easier when there is high frequency data involved. It creates sharper, more defined peaks. This is an argument in support of aligning TA first.

However, crossovers and EQ affect phase. So if you align your TA first, you might not have proper phase alignment after you set your XOvers and EQ. So you might have to revisit your alignment again.


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## Babs (Jul 6, 2007)

Remember the old center track? IASCA disk maybe.. A dead center miraca or shaker or something like that. ch ch ch ch ch ch.. you get the drift. I tell ya, I used that the other evening, eyes closed, +- on the TA, and I don't think I've ever had more dialed in TA and phase in the front stage. I've used several of the type but that one clicked, no pun intended.. I could tell even it seemed when LT and LM phased up in the crossover region. That might sound far fetched. But it's nice because it's got high freq and mid freq information in a wide range, so I dialed everything up front with it. New discovery for me.

But I'm hoping at the meet one of you guys will show me these other software goodies. I'm all about having lots in the toolbox.


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## swyner (Oct 24, 2015)

subterFUSE said:


> Reading an Impulse Response is easier when there is high frequency data involved. It creates sharper, more defined peaks. This is an argument in support of aligning TA first.
> 
> However, crossovers and EQ affect phase. So if you align your TA first, you might not have proper phase alignment after you set your XOvers and EQ. So you might have to revisit your alignment again.


Great point and will do that. One thing I have never seen is someone using their sub (furthest from driver) as the reference...can you do this? Or is it better to use a higher frequency channel like rear right or front right that is almost as far away as the sub?


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## Babs (Jul 6, 2007)

swyner said:


> Thanks for the direction to the stickies....was reading a lot and trying to absorb...a couple of common questions that come up that seem to never really get answered (probably because there is no "right" answer) but should one perform T/A on all the channels BEFORE or AFTER you start all your measurements, EQing, etc??? Also, now that REW has the ability to do T/A with the USB mic, has anyone confirmed this works well? If so, anyone have good step by step? Getting my mic on Friday so will be tinkering with this soon!!!



There is a right answer.. Frequency match (balance) your sides with EQ and have your crossovers set BEFORE time alignment. You can still adjust EQ of course but you want the sides pretty darn close to each other before aligning them. 

And the short answer why: You know you can steer image by leveling. Think freq balancing as leveling to center throughout the bandwidth of the driver pair. 

Disclaimer as Subterfuse can attest. I'm a newb at this myself.  But trust me on that ^


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## Babs (Jul 6, 2007)

Hanatsu thanks for the tip. Worked great to show target curve over plots in REW SPL screen. It shows me, the curve I have chosen as a custom curve, even more sloped and bass-aggressive than most including the JBL curve, is unobtainable for me utilizing the mids I'm running from 80-2k in 2-way. The dips in midrange render them with a massive amount of cut necessary in the ballpark of 20db or so to flatten their midbass response to their midrange. So while I see the limitation, it's quite enlightening as to how this system is driving its resulting tune. 


Sent from iPhone using Tapatalk


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## percy072 (Feb 13, 2014)

HELIX!! :thumbsup:

Many hours back and forth but it's sounding very nice. 



I cannot understand the rise and then hard dip from 500hz-800hz?? I tried overlapping the mid/midrange x-over's, messed with phase withing the DSP TA window, but it's consistent  And still with that persistent hole @ 70hz?? tried 180 deg phase, physically wiring the sub reverse polarity but it won't go away?? Ah well


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## strohw (Jan 27, 2016)

Measure the sub response in the back seat real quick. Just hold the mic back there and do a quick sweep. You probably have a null in your drivers seat. My crew cab truck has one in the drivers side seat that's worse than yours. The passenger side probably has one as well but I don't venture there very often. Last time I sat there it sounded like Michael Jackson was hiding in my air vent so I try not to go back. 

Edit: In reference to the 70hz issue.


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## sicride (Oct 26, 2014)

What happens if you move the crossover from 1k down to 500-600hz? You may benefit from crossing your tweeter a little lower also to avoid beaming of your mid, even tweeters get a little inconsistent in dispersion around 6k sometimes. Did this post mean you switched to a Helix DSP? If so there is more phase options than 180* and 0*. Or you can still play with time alignment to fix that dip at 70hz.


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## percy072 (Feb 13, 2014)

strohw said:


> Last time I sat there it sounded like Michael Jackson was hiding in my air vent so I try not to go back.


Har...:laugh: 



sicride said:


> What happens if you move the crossover from 1k down to 500-600hz? You may benefit from crossing your tweeter a little lower also to avoid beaming of you mid, even tweeters get a little inconsistent in dispersion around 6k sometimes. Did this post mean you switched to a helix DSP? If so there is more phase options than 180* and 0*. Or you can still play with time alignment to fix that dip at 70hz.


Yes just got the Helix in this morning and still getting familiar with it. The H-800 it replaced was a great unit, but I needed something that could take a higher input voltage, plus the 30 band per driver PEQ is also very very nice 

I will play with those x-over' and see how that responds...I just wanted to stay well above the FR of those little midranges.


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## sicride (Oct 26, 2014)

Awesome, I think the Helix is a much better platform unless you need Dolby Pro Logic. 

600hz appears to still be 2 octaves above Fs for those mids. You should be ok even with 12db/octave slope. You could go much lower safely with 24db slopes.

With Helix you can group all the mid's/tweeters in the time alignment screen and delay them together to adjust for that suck out at 75hz. Why don't you cross your mids at 50hz and your sub at 120hz for a little while, play a 75hz test tone generated by REW and measure SPL while you adjust phase or time alignment till it measures as high as possible. Then reset your crossovers to where they should be.


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## percy072 (Feb 13, 2014)

sicride said:


> Why don't you cross your mids at 50hz and your sub at 120hz for a little while, play a 75hz test tone generated by REW and measure SPL while you adjust phase or time alignment till it measures as high as possible. Then reset your crossovers to where they should be.


I've actually tried to cross that Arc sub as high as possible...it always ends up with that same response. Those mids will play low, I can try messing with those but I usually listen pretty loud. 

I have an RE audio SEX10 V2 coming in any time now, not sure what difference that will make...it's probably an issue with the enclosure (even with poly stuffing)


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## sicride (Oct 26, 2014)

Oh I meant overlapping crossovers a good bit so you can adjust and measure for phase coherence.


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## percy072 (Feb 13, 2014)

Think things are starting to come together...there is still something at higher volumes a little sharp? but at normal to "getting louder" is very nice.

I think the new tweeters being alum. dome may be contributing to whatever I'm hearing as "sharp" otherwise they really add a nice crisp and clean top end. 



Think I can stop obsessing for a bit


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## percy072 (Feb 13, 2014)

sicride said:


> there is more phase options than 180* and 0*. Or you can still play with time alignment to fix that dip at 70hz.


I ended up physically wiring the left mid reverse polarity, and also switching it to 180 deg in the TA window, then set the sub to 360 deg...that ended up helping to close the gap at the mid/sub area. 

Sub is the only thing adjustable between 0 and 360 deg correct?? everything else is just 0 or 180 deg (that I could figure out)


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## subterFUSE (Sep 21, 2009)

percy072 said:


> I ended up physically wiring the left mid reverse polarity, and also switching it to 180 deg in the TA window, then set the sub to 360 deg...that ended up helping to close the gap at the mid/sub area.
> 
> 
> 
> Sub is the only thing adjustable between 0 and 360 deg correct?? everything else is just 0 or 180 deg (that I could figure out)




If you're talking about the Helix, then no.

You can make any channel have either 0/180 polarity flip, or 11.5 degrees phase angle steps. It just depends what designation you apply to that channel in the I/O menu.

High, Mid and Sub get phase angle adjust.

Low, Full get 0/180 polarity invert.


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## percy072 (Feb 13, 2014)

subterFUSE said:


> If you're talking about the Helix, then no.
> 
> You can make any channel have either 0/180 polarity flip, or 11.5 degrees phase angle steps. It just depends what designation you apply to that channel in the I/O menu.


I have to use the 2.93 version, I cannot get the new version software to work with my I/O set up properly  I get everything but the tweeters?!?!

I've been chasing my tail on this one...but so far it seems I'm stuck using the older version software that does not have those phase adj. features.


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## sicride (Oct 26, 2014)

Honestly, everything you said you did was returning it to the same it was originally. It seems like you have a time alignment issue... I'd swap the polarity back and return all phase to 0. Then adjust time alignment with the crossovers overlapped and playing a test tone in that overlap while measuring spl, adjust the time alignment until spl reaches its highest point. Or measure distance physically for each driver and enter that then adjust only the subs phase in intervals less than 180* until you get the highest SPL. With what Hanatsu was showing us Helix does to the signal I plan to use phase adjustments as little as possible until I better understand my group delay problems and can intentionally change them with this.


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## sicride (Oct 26, 2014)

So I had a new system installed in my Avalon and have been having a lot of trouble with it. First off, had a bad amp hooked up to my high's and kept getting popping noises from my left tweeter only that would go away after a little bit. Eventually they went away forever and so did all other sounds from that tweeter... Oh then the amp kept going into protect... New amp in, waiting on another tweeter... Spent an hour and a half tuning what I could today a little. Yes, my left mid is high passed only at this time.

Before and after Left Mid









Before and after Right Mid and Tweeter









Left vs Right + Sub individual drivers AND Right side full range









I'm pretty satisfied with the sound of it for as little effort as I put in. I am also having problems getting my gains set for the subwoofer, may have a bad DSP. Just got one of those DSO Nano oscilloscopes and there is a lot of distortion even at very low volumes on the RCA's and I cannot get the output voltage of the amp anywhere near where it should be.

Imaging is complete crap and right side biased BIG time. Hopefully that is 100% because of the missing tweeter.


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## Hanatsu (Nov 9, 2010)

Swap subwoofer channel with mids and use the phase shift on mids


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## sicride (Oct 26, 2014)

What would I be trying to accomplish with that? More than happy to give it a try, just not sure what you're getting at?

or perhaps it is a late response to percy?


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## Hanatsu (Nov 9, 2010)

Just swap rca cables, use mids on subwoofer channel and sub on midbass channel. IIRC the phase shift is only available on G/H channels.


Sent from my iPhone 6 using Tapatalk.


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## swyner (Oct 24, 2015)

Hey guys...got my USB mic today, going to do some work over the weekend. Quick question...I have rear full range, lower door 6.5 mids and upper door/dash mid/tweeter as my 6 channels (plus subwoofer). With the mid/tweeter on passive crossover as 1 channel from my DSP, what should I see the HPF at before I start testing?


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## subterFUSE (Sep 21, 2009)

swyner said:


> Hey guys...got my USB mic today, going to do some work over the weekend. Quick question...I have rear full range, lower door 6.5 mids and upper door/dash mid/tweeter as my 6 channels (plus subwoofer). With the mid/tweeter on passive crossover as 1 channel from my DSP, what should I see the HPF at before I start testing?




The tweeters are the only drivers that need protection from test noise.
I would put a high pass on them at 2X Fs with 24 dB slope to be safe.

The rest of the speakers can be tested without crossovers so you can see the natural response. Then you can choose a suitable crossover point based on the measurements.


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## percy072 (Feb 13, 2014)

Hanatsu said:


> Just swap rca cables, use mids on subwoofer channel and sub on midbass channel. IIRC the phase shift is only available on G/H channels.


I was able to get the I/O configuration set up properly using the 3.31 software, I'm spending waaaaaaayyyyy too much time trying to get the sound I'm hoping to achieve...I think (for me) trying to use it for OEM applications just ain't gonna get there. 

Bottom end is always too tight and thumpy...not able to get that nice visceral warmth  

...bummer


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## Hanatsu (Nov 9, 2010)

percy072 said:


> I was able to get the I/O configuration set up properly using the 3.31 software, I'm spending waaaaaaayyyyy too much time trying to get the sound I'm hoping to achieve...I think (for me) trying to use it for OEM applications just ain't gonna get there.
> 
> Bottom end is always too tight and thumpy...not able to get that nice visceral warmth
> 
> ...bummer


Measure full system, all speakers running. Wanna see the shape of the curve.


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## percy072 (Feb 13, 2014)

Hanatsu said:


> Measure full system, all speakers running. Wanna see the shape of the curve.


this was my last final overall response using the Helix...looks ok, but the sound was just too "hard" on the bottom end. 

I've got my MS-8 in for now...I dunno what it does, but it must be able to extract more from the OEM HU??


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## Hanatsu (Nov 9, 2010)

percy072 said:


> this was my last final overall response using the Helix...looks ok, but the sound was just too "hard" on the bottom end.
> 
> I've got my MS-8 in for now...I dunno what it does, but it must be able to extract more from the OEM HU??




Pull down 40-60Hz a bit. 200-300Hz by 6-7dB. Be careful if you got peaking in the 120-150Hz area, might get very boomy or "hard" sounding otherwise. Try pull up the entire upper midrange a bit.


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## Hanatsu (Nov 9, 2010)

Yeah, increase midrange level by 5dB, tweeter level by 5-7dB too


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## strohw (Jan 27, 2016)

percy072 said:


> I think (for me) trying to use it for OEM applications just ain't gonna get there.


OEM application? What is your source exactly? Are you fighting against some kind of processing OEM side? The Helix doesn't really compare to the MS8 in its ability to negate that issue.


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## sicride (Oct 26, 2014)

Now that looks like a fun curve to shoot for Hanatsu. Can you share that house curve file?


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## Old Skewl (May 30, 2011)

I would love some direction on tuning my M3. I not sure what is causing the lasrge dip at 2khz. Below is the graph of left and right separately. Yellow is left and green is right. I am using an Alpine PXA-H700 for tuning. For some reason my sub is only active on the right channel. EQ is zero and Crossovers are set at:

125 hz 12db sub
80 hz 12 db mid
2.8 khz 18db mid & tweet


and T/A was measured and entered.


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## Hanatsu (Nov 9, 2010)

sicride said:


> Now that looks like a fun curve to shoot for Hanatsu. Can you share that house curve file?



I just did that in paint to highlight what changes he could try in his setup.

A curve is easy to make. Just make a txt file and type

Freq dB

Like:

20 10
40 8
80 6

Etc...


Sent from my iPhone 6 using Tapatalk.


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## Babs (Jul 6, 2007)

sicride said:


> Now that looks like a fun curve to shoot for Hanatsu. Can you share that house curve file?



House Curves out the Yin Yang


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## Hanatsu (Nov 9, 2010)

https://www.dropbox.com/s/5flmtsvsnu1gk88/curves.rar?dl=0

Here's five target curves I've compiled.


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## Babs (Jul 6, 2007)

Probably not the place to put it, but I've realized it's nice to be able to help others who may be new to the different tools or who are just getting off the starting blocks learning the different tools or a certain DSP tool that's new to them. 

Makes me think it wasn't that long ago I was a complete newb at this. I'm certainly no great expert at the moment, and no pro at this tuning thing yet, but glad to help others gaining experience from what little I've managed to learn using these tools like REW, the Helix software, tuning in general. 

Just thought I'd share that. And say thanks to those guys, you know who you are, who've helped me along the way as well, to trudge through the learning to get some skills myself as I try to continue to learn and advance from novice rookie amateur to the next levels. 

Carry on. 


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## Old Skewl (May 30, 2011)

Old Skewl said:


> I would love some direction on tuning my M3. I not sure what is causing the lasrge dip at 2khz. Below is the graph of left and right separately. Yellow is left and green is right. I am using an Alpine PXA-H700 for tuning. For some reason my sub is only active on the right channel. EQ is zero and Crossovers are set at:
> 
> 125 hz 12db sub
> 80 hz 12 db mid
> ...


Can anyone give me some direction? I am a newbie at this as well. I have played with some auto tune DSPs, but wanted to give manual tuning a try. I have played around with the crossovers, T/A, and phasing. I made a few cuts in some problem areas, but don't seem to be getting much in the way of results. Would a combined graph be more beneficial?


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## sicride (Oct 26, 2014)

Well, if you look at a different way it may not be so much a dip at 2k as a peak at 1.2k, especially on the right. Knock down 3.8k area on left tweeter a bit then raise the left side tweeters output all together a little to match the right.

Bigger question, what happened to the left mid below 250hz???

Overlapping your crossover from Sub to Mid probably isn't the best idea. It's likely to make the sub more localizable and will likely cause a lot of undesireable phase interactions. Most people prefer to match crossovers like LP sub at 80hz 24dB/oct and high pass mid at 80hz 24dB/oct. What made you want to cross the sub at 125hz?


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## strohw (Jan 27, 2016)

First thing you need to do is change your Y axis to 5db increments instead of 10db. 

Summary of steps to ball park everything:

-Pick a curve you want to aim for or try
-Rough in T/A by measurement
-No EQ on subs or mids and 1khz 24db+ HP on tweeters
-Measure each mid and tweeter then do 1/3 smoothing to see if levels are close to each other and adjust if there are large differences.
-EQ each driver individually to match curve
-Set crossovers to match acoustically slopes 
-EQ mid+tweeter on each side about 1/2 octave above and below crossover point to smooth it out


-Set time alignment for mids/tweets with holmimpulse or by whatever method you want
-Find out your max left over delay and add most of it to your front stage. I.E. if you have 20ms of total available delay and you used 2.5ms at most for 1 speaker than add 17ms of delay to all front stage speakers.
-Use correlated pink noise to center your mids from 1khz till you can't hear them anymore
-Use correlated pink noise to center your tweeters from 16khz down to you can't hear them anymore
-Start at 0ms delay on sub and then measure subs+mids all together from 20hz-150hz at 1ms intervals. Note all of the intervals that sum the best in REW and sound the best during the test. Test each of these intervals to see which one gives the best impression of upfront bass.
-EQ the subs+mids together after finalizing the time alignment setting on the subs


That should get you to a place where things sound good. From there you can expand on details, try new things or just play around.


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## Old Skewl (May 30, 2011)

sicride said:


> Well, if you look at a different way it may not be so much a dip at 2k as a peak at 1.2k, especially on the right. Knock down 3.8k area on left tweeter a bit then raise the left side tweeters output all together a little to match the right.
> 
> Bigger question, what happened to the left mid below 250hz???
> 
> Overlapping your crossover from Sub to Mid probably isn't the best idea. It's likely to make the sub more localizable and will likely cause a lot of undesireable phase interactions. Most people prefer to match crossovers like LP sub at 80hz 24dB/oct and high pass mid at 80hz 24dB/oct. What made you want to cross the sub at 125hz?


I did try a couple of the cuts you recommended this morning, but don't have access to the screenshots atm. I did figure out how to get sub output on my left channel as well. I had the center channel switched to be a sub output, but got nothing out of the left. When I turn off the center all together, then it works. Wierd! As per your question regarding the mid, this goes to show what you lose by having your mid baffled by the door card and not mounted to the metal door. Unfortunately I don't have the balls to cut my doors on my low mileage M3.


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## Babs (Jul 6, 2007)

Old Skewl said:


> Can anyone give me some direction? I am a newbie at this as well. I have played with some auto tune DSPs, but wanted to give manual tuning a try. I have played around with the crossovers, T/A, and phasing. I made a few cuts in some problem areas, but don't seem to be getting much in the way of results. Would a combined graph be more beneficial?



Are you sure you're in phase in that area? Might just check that with time alignment between tweets and mids by toggling +- a bit in each direction and see if all sudden that area flattens / fills in.


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## Old Skewl (May 30, 2011)

strohw said:


> First thing you need to do is change your Y axis to 5db increments instead of 10db.
> 
> Summary of steps to ball park everything:
> 
> ...


Thanks for the summary of set up. I will try to go through and make sure things are set up properly



Babs said:


> Are you sure you're in phase in that area? Might just check that with time alignment between tweets and mids by toggling +- a bit in each direction and see if all sudden that area flattens / fills in.


I have flipped the phase a few times on the mids and tweets and have not seen any significant changes. I did them as a pair though. Maybe I need to do them individually


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## Babs (Jul 6, 2007)

Old Skewl said:


> I have flipped the phase a few times on the mids and tweets and have not seen any significant changes. I did them as a pair though. Maybe I need to do them individually


Might be a good idea for test.. However if I'm reading your plots, the dip shows on each side playing individually which elludes to a dip between tweets and mids. 

Also consider though, especially in upper frequencies, if they're not aligned perfectly and in phase, they might just be slightly out of phase at normal, and flipped phase. 

Try this.. Mute all but one side. Play a tone or 1/3 octave pink noise centered in the area of the dip. Toggle one driver's timing against the other driver a little and see what happens. Better? Worse? 

Also, it might very simply just be destructive reflections between the two drivers when played together.. Thus if I couldn't nail it down to a driver alignment or phase issue, I'd probably just knock down the peaks on each side of it, make it flat with EQ and continue on.

Is the dip there if tweets are muted? 

Compare your individual driver plots to these plots with driver sides, and also driver pairs (left right).. You may see a correlation to troubleshoot.

Keep in mind, drivers together will have certain anomalies in car because of all the constructive and destructive reflections going on. There is that chance even if you know to the end of the earth you're perfectly aligned and phased, that reflections are commonly destructive there for each side.

I'd also address the balance issue between your mids 250-700hz region as well.. If you timed to that by ear, you're likely off. Which is why I'm a fan of EQ balancing and smoothing individual drivers first before any TA work can be considered "on the money".

Me = armchair QB today. LOL!


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## bradknob (Oct 26, 2009)

Here's my measurement. The green was my first, and current, tuning session with the new 3 way setup and no sub. I was trying to simulate the JBL curve from memory. I really like the pinpoint image and staging of this tune so far. Tonality is really nice but Midbass is a little hot. After searching this thread, I found hanatsus' house curve (in red) that looks like something I would really like. I think I need To work on X-over and slope a bit to smooth the transition from midbass to midrange. So that's what I will shoot for in my next session. Anyone have experience with it?


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## bradknob (Oct 26, 2009)

I've got question for all of you...

When all tuning is done, or close to done, what kind of volume are you getting or do you like to have?

I like to listen loud, 95db + at times... I find that after all the EQing, i just don't get the volume I want. What level do y'all end up or prefer to listen to?


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## Hanatsu (Nov 9, 2010)

I can push my system beyond 130dB after tuning...


Sent from my iPhone 6 using Tapatalk.


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## bradknob (Oct 26, 2009)

Hanatsu said:


> I can push my system beyond 130dB after tuning...
> 
> 
> Sent from my iPhone 6 using Tapatalk.




Well sonamabitch..... Maybe I should mention that is minus subwoofer but still.

Been quite a while but I guess I better go back over a few of your threads, and see where I'm going wrong.....which by the way have been priceless for me as I figure all this out. Thanks for all you have done.


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## Hanatsu (Nov 9, 2010)

bradknob said:


> Well sonamabitch..... Maybe I should mention that is minus subwoofer but still.
> 
> Been quite a while but I guess I better go back over a few of your threads, and see where I'm going wrong.....which by the way have been priceless for me as I figure all this out. Thanks for all you have done.



Lol, the rest of the system won't do 130dB though 

110 should be no issues though. Perhaps check if gain are set too low after all the EQ cuts?


Sent from my iPhone 6 using Tapatalk.


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## brumledb (Feb 2, 2015)

This is my current tune I am working on. The initial crossover setting is LR4 at 2750 for both HPF and LPF. 

Any ideas what could be causing that dip at 3.5k-7k?



Left and Right Tweets







[/URL][/IMG]


Left and Right Tweets Combined







[/URL][/IMG]

Left and Right Mids







[/URL][/IMG]

LEft and Right Mids Combined







[/URL][/IMG]

Tweets and Mids Combined with Crossover







[/URL][/IMG]


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## subterFUSE (Sep 21, 2009)

bradknob said:


> I've got question for all of you...
> 
> When all tuning is done, or close to done, what kind of volume are you getting or do you like to have?
> 
> I like to listen loud, 95db + at times... I find that after all the EQing, i just don't get the volume I want. What level do y'all end up or prefer to listen to?


This is one of the trade-offs for setting amp gains first.

If you set the gains and then start to EQ the DSP down, you're giving up SPL.

If you tune your DSP and then set your amp gains, you'll get more SPL but at the risk of higher noise floor.


There isn't a right or wrong answer. Just a choice to be made.


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## Hanatsu (Nov 9, 2010)

Gains are all about maximizing S/N ratio. I set gains after tuning. Base the settings off the least sensitive driver. You could even run a test sine at the frequency with highest amplitude in DSP (this will be the output limit) before clipping.


Sent from my iPhone 6 using Tapatalk.


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## bradknob (Oct 26, 2009)

subterFUSE said:


> This is one of the trade-offs for setting amp gains first.
> 
> 
> 
> ...




Ive always set the gains first. I'll give this a shot with gains set afterwards, thanks.


I knew there was trade offs in spl I was just curious of what the average trade off was for others. Just to tame my expectations a bit I guess


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## percy072 (Feb 13, 2014)

Hanatsu said:


> Pull down 40-60Hz a bit. 200-300Hz by 6-7dB. Be careful if you got peaking in the 120-150Hz area, might get very boomy or "hard" sounding otherwise. Try pull up the entire upper midrange a bit.


Finally getting things better but it took hard cuts in the midbass region so now it doesn't sound like the 6.5' won't come flying out the door on me! and you can see I had to keep the upper midrange region up to "keep up"....

this is just a shot of the Left midbass, Right is not much better...



What could be causing a much higher mid vs midrange response?? Is that "normal" at all?? BTW...I'm back to just front Mid/tweeter set up (for now) taken the midrange driver out of the loop.


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## percy072 (Feb 13, 2014)

Current overall response...still that retarded black hole at 70hz that will not go away!! and now this dip at 500hz 

The fun continues...



Now I seem to have a lack of output after hacking down the midbass region so much...ugh


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## Hanatsu (Nov 9, 2010)

The hole at 70Hz is a modal null. Can't EQ that. You can EQ everything around it but then you lose output and risk high distortion within the null.

Either it's from the sub or mid, use lower crossover and let mid reproduce it. Then again, output will be limited.

Sent from my iPhone 6 using Tapatalk.


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## Babs (Jul 6, 2007)

percy072 said:


>


Is it me, but don't those seem like rather sharp EQ cuts? I kinda always thought you wanted to avoid really high-Q cuts like that for that much of a cut, because of induced ringing. No?


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## percy072 (Feb 13, 2014)

Hanatsu said:


> Either it's from the sub or mid, use lower crossover and let mid reproduce it. Then again, output will be limited.


I've been able to close that gap by doing goofy things with the sub and midbass EQ, crossover's etc...but as you've mentioned, I have to keep the volume down or it gets a little out of control.



Babs said:


> Is it me, but don't those seem like rather sharp EQ cuts? No?


I agree...it bother's me to have to weed wack that lower midbass region, Always had higher output up to approx. 350-400hz then it drops way down. 

I'm almost wondering if a lower QTS midbass would make any difference??My doors are sealed up pretty tight.


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## brumledb (Feb 2, 2015)

percy072 said:


> I've been able to close that gap by doing goofy things with the sub and midbass EQ, crossover's etc...but as you've mentioned, I have to keep the volume down or it gets a little out of control.
> 
> 
> 
> ...


Have you tried or are you letting REW EQ to your curve?


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## Hoptologist (Sep 14, 2012)

What's going on here? I've zoomed in on two measurements that are otherwise identical, except for the area surrounding the 80Hz xover point.

Both measurements are with sub+lw+rw. Yellow is normal and green is with the sub's phase inverted inside the BitOne software. I then included additional measurements of the sub and lw+rw. LP on sub is 80Hz Linkwitz, HP on mids is also 80Hz Linkwitz.

It seems like the sub and lw/rw are summing correctly when the sub's phase is inverted, giving me a boost over my sub measurement (purple), but summing incorrectly between 85-120Hz giving me a loss over my lw/rw measurement (blue). And conversely, without the sub's phase inverted, I'm losing output from 60-78Hz compared to the sub's baseline, but then gaining between 80-120Hz over the lw/rw baseline. How come? Should I leave my sub inverted?


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## sicride (Oct 26, 2014)

It looks like you are out of phase but not 180* out of phase, so maybe you're 30* out of phase when set to 0* phase and 210* out of phase when you flip the switch to 180*.

You might want to play more with the time alignment and try different crossover slopes/types to find a compromise. I am still learning but from what Hanatsu has been talking about recently the phase switch may be basically an all pass filter and effecting group delay which can lead to destructive interference at different frequencies. But I'm probably misunderstanding this. To play it safe I try to leave phase at 0 and adjust time delay instead.


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## Hanatsu (Nov 9, 2010)

What Sicride said; you probably are 90-130deg out of phase. T/A till you get a complete null then swap phase.


Sent from my iPhone 6 using Tapatalk.


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## bradknob (Oct 26, 2009)

bradknob said:


> I've got question for all of you...
> 
> When all tuning is done, or close to done, what kind of volume are you getting or do you like to have?
> 
> I like to listen loud, 95db + at times... I find that after all the EQing, i just don't get the volume I want. What level do y'all end up or prefer to listen to?




Pertaining to my question earlier, I found part of the issue. I didn't mention it but I'm using hi level inputs to my helix from a grand Cherokee oem amp...

I built a remote for the helix pro to use when I ran a digital signal. I downloaded some pink noise to my ibasso, and ran it straight to the helix and took some measurements. This is sub and 3 way front, X-overs and T/a only. No eq.

Red = response using aux in of oem system
Blue = response of optical in straight to dsp. Bypassing oem system.



The factory processing is sucking the life out the mid range so I wind up cutting everything around it to match..... Giving up spl.


With that said, I did manage to get a nice response, Ima just have to live with the volume for the time being. Hanatsus house curve. I may end up boosting the bottom end a bit more to my liking but over all, very nice sounding curve


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## sicride (Oct 26, 2014)

I am actually doing a similar thing today. Started over because I now have a headphone jack to RCA input for my Helix and response is drastically different. Much cleaner actually from the headphone out. So I guess I'll need to have separate tunes for iPhone and for OEM integration. Plus all passenger tunes for each plus rear fill tunes for each. Thank goodness there's so many presets in the director.

Looks like you were losing at least 5dB leveling that out. Good thing to have figured out and be sure to set your gains so you aren't overdriving one input vs the other. Curve looks great, nice work.


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## bradknob (Oct 26, 2009)

Thanks, it's as good a curve as I've ever gotten. My last vehicle was totaled before I had a chance to really get into the tuning part. So this is uncharted
Territory for me. Imaging and tonaly, it's the best I've ever had.

I didn't realize how drastic the difference would be in signal sources but now It's got me thinking about the director also. Never thought I'd need more thatn 2 different tunes to toggle through. But now it seems to make sense.


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## Hoptologist (Sep 14, 2012)

sicride said:


> It looks like you are out of phase but not 180* out of phase, so maybe you're 30* out of phase when set to 0* phase and 210* out of phase when you flip the switch to 180*.
> 
> You might want to play more with the time alignment and try different crossover slopes/types to find a compromise. I am still learning but from what Hanatsu has been talking about recently the phase switch may be basically an all pass filter and effecting group delay which can lead to destructive interference at different frequencies. But I'm probably misunderstanding this. To play it safe I try to leave phase at 0 and adjust time delay instead.





Hanatsu said:


> What Sicride said; you probably are 90-130deg out of phase. T/A till you get a complete null then swap phase.


Thanks guys, I think it's fixed now. I kept the sub's phase inverted and kept decreasing the distance setting in the BitOne. 14.5" gave me the largest null (pink) out of any distance, so I changed the sub's phase back to normal at that setting and it gave me a nice flat summing (orange).










The UMIK-1 has got to be one of the best purchases I've made. I love learning this stuff and have so much fun spending a couple hours a day (or more) taking measurements and making gradual improvements, it's addicting.


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## Hanatsu (Nov 9, 2010)

Hoptologist said:


> Thanks guys, I think it's fixed now. I kept the sub's phase inverted and kept decreasing the distance setting in the BitOne. 14.5" gave me the largest null (pink) out of any distance, so I changed the sub's phase back to normal at that setting and it gave me a nice flat summing (orange).


Best way to do it!


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## sicride (Oct 26, 2014)

Retune day with iPhone to RCA input for Helix DSP. Unfortunately, still haven't put in the replacement left tweeter. I may need to put my other amp in to bridge channels for my mids.

Hertz HSK165 right side response individual drivers pre-eq vs. combined EQ'd









Left vs. Right (missing left tweeter )









I was trying to comromise between two house curves Hanatsu provided










This thread has been a big success and I am glad that so many have contributed and learned from it. Noticed quite a few pictures are no longer visible though, that is quite disappointing. Hopefully, if any of you have removed pictures and read this you might be able to repost them so people in the future can continue to learn from your contributions?


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## Babs (Jul 6, 2007)

Hoptologist said:


>



Ya know that's one I've not tried before phasing in sub using REW. I'd always done it by ear. That's pretty cool.


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## sicride (Oct 26, 2014)

Got a question, see the ripples in the subs response? Now that's with 1/12 smoothing which I understand no smoothing at those frequencies is preferred, however if I tried to EQ one of those bumps it would cut there but the dips basically flipped kind of like you see between those two measurements sub by itself and all together. Why would this be happening? I tried undoing the cut and boosting the valleys, same effect. Tried boosting dip and cutting peaks same thing depended which I cut or boosted more. I imagine it's a modal thing but don't quite understand why it would flip flop like that.


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## lowcel (Dec 28, 2014)

Hope you all don't mind if a new guy jumps in the thread. I absolutely suck at tuning but I'm giving it my best shot. I upgraded my mid bass and mid range yesterday so I'm kind of starting over. 

This evening I worked on the mid range and tweeters. 

Here are the tweeters, right is red. 










Here are the tweeters and mid range separate. Right is red. 










Here are the tweeters and mid range together. Right is red, blue is left, green is all of them on at once.


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## unix_usr (Dec 4, 2013)

How is everyone overlaying a target curve? I've see. The "house" curve a few times now provided by hanatsu has been posted, is there a file or anything where that's shared?


Sent from my iPhone using Tapatalk


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## bradknob (Oct 26, 2009)

unix_usr said:


> How is everyone overlaying a target curve? I've see. The "house" curve a few times now provided by hanatsu has been posted, is there a file or anything where that's shared?
> 
> 
> Sent from my iPhone using Tapatalk




Under "file" in the top left choose "import target response" (something like that, I'm not in front of my computer). Then it will add it to the list of measurements on the left and you can display it in the all spl screen.

Or were you looking for the house curve files themselves?


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## Justin Zazzi (May 28, 2012)

unix_usr said:


> How is everyone overlaying a target curve? I've see. The "house" curve a few times now provided by hanatsu has been posted, is there a file or anything where that's shared?


I might be a little partial to this method, but I like using the tool I built for making house curves. See the link in my signature below to download the excel spreadsheet. \/


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## brumledb (Feb 2, 2015)

My latest attempt at tuning.....

The nasty dip at 500-600hz is there with only the mids playing as well.








[/URL][/IMG]


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## bradknob (Oct 26, 2009)

^^^ ur getting there. My mids have a nasty dip from factory processing. I have cut everything to match it at the cost of volume and another tune just disregarded it and worked everything around it and there's not that big of a difference.

Here's where I ended up. I tweaked Hanatsus house curve to add some more bottom end...

Not sure what's up with the sub measurement shooting across like that. I played with the EQ In the 200 range just see if it changed anything but nada. Target curve is in yellow




Combined response in green



Here's response over the target...



Still a bit more tweaking but over all, I love the sound here. The staging is the deepest I've ever achieved in my own vehicle. Seems to be beyond the windshield. Also the space between instruments on the stage greatly improved. I like where this is going


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## EmptyKim (Jun 17, 2010)

unix_usr said:


> How is everyone overlaying a target curve? I've see. The "house" curve a few times now provided by hanatsu has been posted, is there a file or anything where that's shared?
> 
> 
> Sent from my iPhone using Tapatalk


House curves people are talking about.

http://www.diymobileaudio.com/forum/1828201-post16.html
http://www.diymobileaudio.com/forum/1828589-post22.html


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## sicride (Oct 26, 2014)

Bradknob have you compared left side drivers vs right side drivers yet? That's where the soundstage REALLY seems to open up in my experience. Looks great so far with overall tonality.


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## bradknob (Oct 26, 2009)

sicride said:


> Bradknob have you compared left side drivers vs right side drivers yet? That's where the soundstage REALLY seems to open up in my experience. Looks great so far with overall tonality.




Yes, that's usually the first thing I do. Level match each side and save that tune for later/different tunes. that way half the works done already and you should have a nice center image. Then shape them together, and like you said, at that point it sounds like a completely different system. 

Give me a few, I'll get my individual speaker measurements .


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## sicride (Oct 26, 2014)

That's a good way of doing things, that sounds like it would be especially productive with the Helix DSP since linking all drivers will not negate prior adjustments just adjust from the current settings. So much fun ahead and things seem like they will be so much quicker with this processor.


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## bradknob (Oct 26, 2009)

I came from an ms-8, now to the helix pro. Difference is like a moped to a maybach.


Here's individual speakers












This is actually before I shaped everything as pairs. I'll have to take some new individual measurements and report back


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## lowcel (Dec 28, 2014)

I was able to get the left and right matched up pretty well.










Then together.


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## sicride (Oct 26, 2014)

They do match up quite well. I see you used 1/48 smoothing here, but what resolution were you using to measure? Looks almost like 1/6 octave RTA with 1/48 smoothing on top of that? 

Does this sound bright to you? Some of the midbass measurement looks like it could use EQ outside of its passband, though it doesn't seem to be effecting overall tonality it may be effecting the imaging.


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## lowcel (Dec 28, 2014)

sicride said:


> They do match up quite well. I see you used 1/48 smoothing here, but what resolution were you using to measure? Looks almost like 1/6 octave RTA with 1/48 smoothing on top of that?
> 
> 
> 
> Does this sound bright to you? Some of the midbass measurement looks like it could use EQ outside of its passband, though it doesn't seem to be effecting overall tonality it may be effecting the imaging.




1/3 octave RTA. I have no idea of the smoothing. I'm still pretty new to this.


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## sqnut (Dec 24, 2009)

sicride said:


> Some of the midbass measurement looks like it could use EQ outside of its passband, though it doesn't seem to be effecting overall tonality it may be effecting the imaging.


The mid bass rise in the stop band from ~600-1.6 will need to be tamed with the eq, yes. This rise will 100% affect tonality not the imaging.


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## lowcel (Dec 28, 2014)

sqnut said:


> The mid bass rise in the stop band from ~600-1.6 will need to be tamed with the eq, yes. This rise will 100% affect tonality not the imaging.


I'll work on leveling it out some more in the morning. I plan on messing with it another hour or two then getting to work on a flat tune for the RTA part of the competition on Saturday.


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## Babs (Jul 6, 2007)

sqnut said:


> The mid bass rise in the stop band from ~600-1.6 will need to be tamed with the eq, yes. This rise will 100% affect tonality not the imaging.






sicride said:


> They do match up quite well. I see you used 1/48 smoothing here, but what resolution were you using to measure? Looks almost like 1/6 octave RTA with 1/48 smoothing on top of that?
> 
> Does this sound bright to you? Some of the midbass measurement looks like it could use EQ outside of its passband, though it doesn't seem to be effecting overall tonality it may be effecting the imaging.



Why not tame that business with lower low pass filter? I'd certainly try to make that go away so midbass is playing midbass and mids are playing mids.


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## lowcel (Dec 28, 2014)

New curves.

Level matching.









Listening curve (for now). 400 hz kills me









RTA curve, 2,000 hz kills me


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## Rtsr21 (Aug 12, 2014)

What do you guys think of this, where would you start to fix it first? It does not sound very good. I would be thankful for any help.


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## bradknob (Oct 26, 2009)

Rtsr21 said:


> What do you guys think of this, where would you start to fix it first? It does not sound very good. I would be thankful for any help.




What are we looking at? Is this with a subwoofer? 2 way? 3 way?

What doesn't sound good to you?

For starters I would kick up that bottom end quite a bit. start with 8db or so and let us know how it sounds from there


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## Rtsr21 (Aug 12, 2014)

bradknob said:


> What are we looking at? Is this with a subwoofer? 2 way? 3 way?
> 
> What doesn't sound good to you?
> 
> For starters I would kick up that bottom end quite a bit. start with 8db or so and let us know how it sounds from there


Yes there is a sub, its 4way i know yous guys can't hear it but does it look bad?


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## EmptyKim (Jun 17, 2010)

Rtsr21 said:


> Yes there is a sub, its 4way i know yous guys can't hear it but does it look bad?


Increase your dB resolution on the left axis. Its at 50 right now. Go to about 5 as with the post above yours provided by lowcel


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## bradknob (Oct 26, 2009)

Rtsr21 said:


> Yes there is a sub, its 4way i know yous guys can't hear it but does it look bad?




Me personally, do not like a flat response like you show to have, particularly in a vehicle. Bass/Midbass is extremely weak and overpowered by vocals.


If I were you, I would bump 60hz and below up 8 db or so. Then let the Midbass slope down from 60-200ish hz . From 200 on up leave flat and see how you like the sound then.

Look at the majority of the responses in this thread, notice they all take a similar shape. Try to mimic Them then adjust from there


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## bradknob (Oct 26, 2009)

EmptyKim said:


> Increase your dB resolution on the left axis. Its at 50 right now. Go to about 5 as with the post above yours provided by lowcel




Oh lawd......... Didnt even notice that. Disregard my previous statement


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## Rtsr21 (Aug 12, 2014)

EmptyKim said:


> Increase your dB resolution on the left axis. Its at 50 right now. Go to about 5 as with the post above yours provided by lowcel


I'm sorry what does that mean? Are telling me to raise the sub?


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## EmptyKim (Jun 17, 2010)

If you hover over your graph, along the left side you should see magnifying glass to zoom in on the left axis.


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## bradknob (Oct 26, 2009)

I just happen to be sitting at my computer,

Go here...









Change the settings similar to this...










Then like emptykim said, you can zoom in our out










Zoom in until the numbers on the side are in 5 or 10db increments.










This way we can get a closer look at what you got going on, then we can help you better


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## Rtsr21 (Aug 12, 2014)

Thank you very much


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## bradknob (Oct 26, 2009)

Better....

It looks really hot on the top end. My ears are almost ringing looking at it. Lol. I would start with 3k hz and up. Bring it down 15db or so. That should help.

I'm assuming you have a dsp of some sort?...I would measure each speaker individually and work on knocking down all of the peaks one at a time.


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## sicride (Oct 26, 2014)

You ain't kidding, that can't sound good at all... Sorry but it's the truth. Although it's nice to know a huge improvement will be easily had by turning the tweeters down and the subs up. The good problem you have is plenty of midbass so you can knock down peaks and still have substance down there. Having the frequencies from 0-20 on the graph is pointless none of that is accurate or relative to what you're hearing or feeling. Honestly with your setup now I see little reason to pay attention below 30hz. No need for measurement below 50dB if your response dips down there you have much bigger problems.


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## Hanatsu (Nov 9, 2010)

Wow... The entire area above 3k must be lowered. The area around 10k should be lowered by 25dB or so lol.


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## Rtsr21 (Aug 12, 2014)

Yeah, i will not have the laptop back until Sunday night, so how bad are those dips? there like 5db and 10db difference.


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## percy072 (Feb 13, 2014)

Man...did this ever make a change...Purple line is with the sub enclosure port open, red line is after packing a towel into the port!! Always the simple things to try that make all the difference...


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## Kazuhiro (Apr 28, 2015)

Damn I bet you can towel the difference


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## percy072 (Feb 13, 2014)

Helix back in, back to three way + sub...bridged amp to midbass' (200 rms each), midrange and tweeters on another amp (50 rms each) sub on 500 rms channel. 

I like the overall detail, really no complaints but can't understand the disproportionate peaks in the overall response compared to the individual drivers?? I guess I can see minor peaks that must be turning into combined "bigger peaks" 

The LPG NA26 tweeters are very nice...although there is that strange hard up swing at 18khz, but I can't hear that anyhow.


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## bradknob (Oct 26, 2009)

percy072 said:


> Helix back in, back to three way + sub...bridged amp to midbass' (200 rms each), midrange and tweeters on another amp (50 rms each) sub on 500 rms channel.
> 
> I like the overall detail, really no complaints but can't understand the disproportionate peaks in the overall response compared to the individual drivers?? I guess I can see minor peaks that must be turning into combined "bigger peaks"
> 
> The LPG NA26 tweeters are very nice...although there is that strange hard up swing at 18khz, but I can't hear that anyhow.



You are correct, peaks are the sum of multiple drivers playing the same Frequency.

For example, where I have circled below, try messing with the mid and woofer beyond where they cross each other (about 250hz for mid range, and about 400-600hz for the Midbass.











Edit.....Look at your X-over point where the mid crosses the tweeter how smooth the transition is them Look at the overall response in that region.... Nice and smooth also


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## percy072 (Feb 13, 2014)

bradknob said:


> where I have circled below, try messing with the mid and woofer beyond where they cross each other (about 250hz for mid range, and about 400-600hz for the Midbass.
> 
> ...Look at your X-over point where the mid crosses the tweeter how smooth the transition is them Look at the overall response in that region.... Nice and smooth also


Yep...I am definitely seeing that. I'll mess around with the mid/midrange x-over's and see if I can get that area cleaned up.


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## Rtsr21 (Aug 12, 2014)

Ok, I think I am finally getting somewhere here, how do these look. Any idea why the slight dip at 200hz on the both doors eq.


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## Rtsr21 (Aug 12, 2014)

Well i just noticed that it drops off at 500hz I have it crossed at 200hz, is this just how it going to be, what would you guys try to do to fix it?


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## lowcel (Dec 28, 2014)

Rtsr21 said:


> Well i just noticed that it drops off at 500hz I have it crossed at 200hz, is this just how it going to be, what would you guys try to do to fix it?


That dip could very well just be a characteristic of the vehicle. Mess with it a little but don't worry about it too much. Dips are far less concerning than peaks.


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## Rtsr21 (Aug 12, 2014)

lowcel said:


> That dip could very well just be a characteristic of the vehicle. Mess with it a little but don't worry about it too much. Dips are far less concerning than peaks.


It was because of T/A, turned it off and the dip went away.


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## lowcel (Dec 28, 2014)

Rtsr21 said:


> It was because of T/A, turned it off and the dip went away.


So are you doing without time alignment all together now or have you turned it back on and started playing with phasing to correct the issue?


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## Rtsr21 (Aug 12, 2014)

lowcel said:


> So are you doing without time alignment all together now or have you turned it back on and started playing with phasing to correct the issue?


yeah without T/A, still can't get it to sound right, more post coming in a couple of days.


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## lowcel (Dec 28, 2014)

Rtsr21 said:


> yeah without T/A, still can't get it to sound right, more post coming in a couple of days.


No way I am going to do without time alignment. I would much rather have a dip. 

Are you able to adjust the phase on your speakers? It sounds like that is what you are dealing with.


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## percy072 (Feb 13, 2014)

You need to set your graph's up...set bottom freq. to read from 20hz - 20khz, try to get the left side to start around 40 at 5db increments and up.

Also...you should be seeing at least a 10db drop from 80hz down to 160 to 200hz (ish) running flat across like that would sound...not so good

Why crossing the mids so low??


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## lowcel (Dec 28, 2014)

Since my 6's and 2's have had some time to break in I decided to mess around with the RTA some more today.

*note, red is always right speaker(s) on my graphs.

First off, level matching. I'm pretty happy with how they look. 










Next up, all speakers together after level matching. Check out that big dip at 400 hz.










I decided to try swapping the phase 180 degrees on the 6's to see what would happen. I'm very pleased with the result.










This is how I left it for the day. I've made a new rule that I will only tune as long as the laptop batteries last. Hopefully this will help keep me from going insane.


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## fcarpio (Apr 29, 2008)

lowcel said:


> This is how I left it for the day. I've made a new rule that I will only tune as long as the laptop batteries last. Hopefully this will help keep me from going insane.


That doesn't work! What if you are not done when you run out of battery? That would drive me bonkers.


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## lowcel (Dec 28, 2014)

fcarpio said:


> That doesn't work! What if you are not done when you run out of battery? That would drive me bonkers.


Next competition isn't until Sunday. I have plenty of time to work on it. It's not like I could ever finish tuning in one day anyway. It's an ongoing process.


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## Rtsr21 (Aug 12, 2014)

Is my right mid anything to be concerned about, probably not but why is the left mid so much smother?


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## bradknob (Oct 26, 2009)

I would have to say the amount of reflective surfaces between ur head and right mid is far greater than that of ur head and left mid. I wouldn't be that worried.


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## Elgrosso (Jun 15, 2013)

Very nice mids!
But same for me, better on left than right. Is it averaged?
Maybe the left glass that cancel some stuff


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## Babs (Jul 6, 2007)

Rtsr21 said:


> Is my right mid anything to be concerned about, probably not but why is the left mid so much smother?



Likewise very nice mids. Yeah that's a big ole dip at 600. I can see your concern. You might consider for giggles trying to see what's inducing that dip on your right mid. For experiment, do some thick absorption of some kind around it. Maybe at the windshield or around it, and see if you can possibly identify the cause. For instance if absorption at one spot or another suddenly dramatically changes your response in a good way, it'll give you a bit of a direction to consider. Also could it be the pillar install itself? Anything is possible. 

The struggle is real brother. Fight the good fight and find the gremlin. My advice.


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## brumledb (Feb 2, 2015)

I have been experimenting with using the null method to phase/time align my speakers. Just wondering if anyone can explain what causes the more broad null dip vs the sharp null dip? The cross-over is set to 90hz.










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## Ziggyrama (Jan 17, 2016)

My guess is, the reflections in the car are triggering broader cancellations in the spectrum?

Can you explain the graphs with respect to your settings?


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## Elgrosso (Jun 15, 2013)

Interesting artcile about that: Aligning Loudspeaker Drivers with Delays: Simulations | Richard's Stuff
But maybe it's also accentuated by the smoothing here. How is it without any?


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## brumledb (Feb 2, 2015)

Ziggyrama said:


> My guess is, the reflections in the car are triggering broader cancellations in the spectrum?
> 
> Can you explain the graphs with respect to your settings?




The only difference in each measurement is the time delay setting. I am playing a band limited pink noise tone and the midbass is flipped to 180. I am holding the mic by hand right at tip of nose for each measurement.


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## brumledb (Feb 2, 2015)

Elgrosso said:


> Interesting artcile about that: Aligning Loudspeaker Drivers with Delays: Simulations | Richard's Stuff
> But maybe it's also accentuated by the smoothing here. How is it without any?




Thanks for the link, I have read that one before but just reread it. I kinda got my answer, I want the deep narrow null as opposed to be more broad one. 

The graphs I posted are not smoothed.


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## Elgrosso (Jun 15, 2013)

brumledb said:


> Thanks for the link, I have read that one before but just reread it. I kinda got my answer, I want the deep narrow null as opposed to be more broad one.
> 
> The graphs I posted are not smoothed.


Ok, by curiosity, what increment did you use between each measurement?
Or in other way, will you use the same method for midrange/tweeters?


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## brumledb (Feb 2, 2015)

Elgrosso said:


> Ok, by curiosity, what increment did you use between each measurement?
> 
> Or in other way, will you use the same method for midrange/tweeters?




Since I was doing sub to midbass I used 1ms increments. Then when I was close I used 0.25ms increments. I am just about to head out to do the mids and tweets. I will use much smaller increments with them. I'll probably try 0.1ms adjustments for the mids to begin with and go from there. I will report back tonight hopefully with some awesome results. 
But using this method to couple sub to midbass has resulted in the best upfront bass I have had so far.


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## Hanatsu (Nov 9, 2010)

Suitable increments can be seen as actual phase shift instead of time offset.

Doing the "magnitude response-null-method", go 15deg up/down to see the effect. This will be dependent on wavelength.

At 50Hz = 1 (sec)/50 (freq) = 20ms

then;

20ms / 360deg = 0,055

0,055*15=0.83ms

i.e 15deg phase shift at 50Hz is 0,83ms. Just change the the frequency and do the math


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## Elgrosso (Jun 15, 2013)

Ok the C-dsp (w/ 0.02ms increment) allows a 26 degrees minimum shift at 3600hz for example.
Pobably more than enough, but how do you adjust this, by checking summing with REW? 
Impulse response?

Not that I care that much with the APL, but I'm curious.
I played with TDA (pre APL), for sub/midbass it's quite efficient, but midranges/tweeters it was just impossible.


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## lowcel (Dec 28, 2014)

Ready for the RTA challenge tomorrow.


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## sicride (Oct 26, 2014)

Wow, that is insanely flat. I'm curious how horrible that actually sounds but it also makes me envious if you can get everything that flat and had a global EQ to adjust for tonality from there it would make it really easy to test and tune separate curves. I know Helix allows you to link, but if you're already using the fine EQ and parametric EQ bands for each individual driver, linking could throw everything wacky.


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## lowcel (Dec 28, 2014)

sicride said:


> Wow, that is insanely flat. I'm curious how horrible that actually sounds but it also makes me envious if you can get everything that flat and had a global EQ to adjust for tonality from there it would make it really easy to test and tune separate curves. I know Helix allows you to link, but if you're already using the fine EQ and parametric EQ bands for each individual driver, linking could throw everything wacky.


I'm sure it does sound horrible. The only thing I will ever listen to with these settings is pink noise.


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## swyner (Oct 24, 2015)

strohw said:


> You can rough in the T/A by measurement first if you want. I would suggest using HolmImpulse for T/A instead of REW.
> 
> The Subwoofer DIY Page v1.1 - Time Alignment using HolmImpulse


So I read through this informative link and started the process. I used my front right highs as the first measurement and then clicked "set zero" "use". Did anyone find that the waves on the graph did not change when doing this? Mine still had some waves below 0 and could not get it to work??
I left it and tried doing my right mid. This was pre crossed over between 100 and 250hz and maybe that was the problem...it did not give me any significant "wave" to match up to the reference measurement. Just trying to get this working and appreciate any help!!!


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## Landshark77 (Jan 1, 2016)

Here are initial REW graphs for Stereo Integrity M25 tweeters and TM65 mids tuned using a Minidsp C-DSP 6x8

My steps were:
Set Gains and individual speaker levels
Set crossovers 
EQ each individual driver
Apply filters and check results
Time align

Crossovers:
65 24db BW & 2500 24db BW Mids
2500 24db BW Tweets

Subwoofer still isn't here, gets in next week. I was trying to get everything flat within 3db and then maybe tomorrow add a bit house curve on the input eq.

How do these look? Any input and am I heading in the right direction?
I first tried a sweep using the measurement tool on REW but didn't like the way it sounded after I auto eq'd it with the C-DSP.
Next I used Pink PN with RTA and auto eq'd from there. Sounded way better.


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## Hoptologist (Sep 14, 2012)

Hoptologist said:


> Thanks guys, I think it's fixed now. I kept the sub's phase inverted and kept decreasing the distance setting in the BitOne. 14.5" gave me the largest null (pink) out of any distance, so I changed the sub's phase back to normal at that setting and it gave me a nice flat summing (orange).





Hanatsu said:


> Best way to do it!


Hey Hanatsu, that method worked perfectly when I had my DD sub. I recently swapped the DD sub for a JBL W15 GTi MKii and left everything else the same including enclosure. I haven't been able to recreate that method using this sub yet.

The only way I've measured dips like that so far is if I leave the phase normal. If I invert the phase, no matter if I adjust the time delay from 0" to 53", I get a relatively smooth sum with the mids and no dips like I did with the DD. Trying to figure out what I'm doing wrong. 

I don't want to leave the sub as inverted, I'd much rather find the deepest null with the phase inverted and then flip it and be at normal phase. Should I keep going past 53" in the BitOne to try and find where it eventually nulls with the phase inverted? My left mid is at 53.5" in the BitOne, so I currently have everything time delayed to that left mid...


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## Jscoyne2 (Oct 29, 2014)

Hoptologist said:


> Hey Hanatsu, that method worked perfectly when I had my DD sub. I recently swapped the DD sub for a JBL W15 GTi MKii and left everything else the same including enclosure. I haven't been able to recreate that method using this sub yet.
> 
> The only way I've measured dips like that so far is if I leave the phase normal. If I invert the phase, no matter if I adjust the time delay from 0" to 53", I get a relatively smooth sum with the mids and no dips like I did with the DD. Trying to figure out what I'm doing wrong.
> 
> I don't want to leave the sub as inverted, I'd much rather find the deepest null with the phase inverted and then flip it and be at normal phase. Should I keep going past 53" in the BitOne to try and find where it eventually nulls with the phase inverted? My left mid is at 53.5" in the BitOne, so I currently have everything time delayed to that left mid...


How do you measure with noise or a test tone in REW. All i know is when you measure it does a FREQ sweep. Is that what your doing or???


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## Hoptologist (Sep 14, 2012)

Jscoyne2 said:


> How do you measure with noise or a test tone in REW. All i know is when you measure it does a FREQ sweep. Is that what your doing or???


I think you can measure with pink noise in the generator option, but I'm just doing the sine sweeps.

Sent from my Nexus 6P using Tapatalk


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## subterFUSE (Sep 21, 2009)

You can measure with sweeps or pink noise. Pink noise is only good for frequency response. For impulse response you must use sweeps in REW. Other programs allow impulse response and transfer function with pink noise, but not REW.


Sent from my iPhone using Tapatalk


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## Rrrrolla (Nov 13, 2008)

Hoptologist said:


> Hey Hanatsu, that method worked perfectly when I had my DD sub. I recently swapped the DD sub for a JBL W15 GTi MKii and left everything else the same including enclosure. I haven't been able to recreate that method using this sub yet.
> 
> The only way I've measured dips like that so far is if I leave the phase normal. If I invert the phase, no matter if I adjust the time delay from 0" to 53", I get a relatively smooth sum with the mids and no dips like I did with the DD. Trying to figure out what I'm doing wrong.
> 
> I don't want to leave the sub as inverted, I'd much rather find the deepest null with the phase inverted and then flip it and be at normal phase. Should I keep going past 53" in the BitOne to try and find where it eventually nulls with the phase inverted? My left mid is at 53.5" in the BitOne, so I currently have everything time delayed to that left mid...


If you're getting the null with "normal" phase, and you haven't changed anything, anything, sounds like your new sub is wired backwards, no big deal, either reverse the polarity of the wiring to your sub, or leave it "inverted" for normal listening, and put the phase "normal" for finding your dips. Inverting phase means flipping polarity. Your new sub might have its polarity labeled incorrectly, I've seen that before.


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## Rtsr21 (Aug 12, 2014)

Well this look's pretty bad, anyone care to chime in and critique this? I can't figure what is going on in the 60hz range, maybe too much mid bass still? I was able to raise it there a little by adjusting the T/A on the sub. The dip at 160 is from the left door. Right door has no dip like that. I have focal tn-53k tweeters, what is with the roll off, I though metal tweeters did not roll off like that?

Sub 60hz 24/db
6.5 Mid 60hz to 150hz 24/db
midrange 400hz to 4500 24/db
tweeters 5000k to up 24/db


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## Drop11 (Jul 4, 2016)

That dip at 60 could be phase, crossover slopes or time alignmet.
The issue with the dip in your mid is likely the caused by the car.
the tweeter roll off is likely tweeter placement , angle.


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## sqnut (Dec 24, 2009)

Rtsr21 said:


> Well this look's pretty bad, anyone care to chime in and critique this? I can't figure what is going on in the 60hz range, maybe too much mid bass still? I was able to raise it there a little by adjusting the T/A on the sub. The dip at 160 is from the left door. Right door has no dip like that. I have focal tn-53k tweeters, what is with the roll off, I though metal tweeters did not roll off like that?
> 
> Sub 60hz 24/db
> 6.5 Mid 60hz to 150hz 24/db
> ...


You have a hole in your midbass, fill that first. Run the 6.5 up to 400 to meet your mid, similarly up the midrange to five. Cut 200&315 a chunk and a couple of clicks from 1.25 to 3.


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## Ziggyrama (Jan 17, 2016)

Measure each speaker individually. If the dip still persists, it means it is the car and/or speaker placement. If the dip goes away, it means phase or TA problem.


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## Rtsr21 (Aug 12, 2014)

sqnut said:


> You have a hole in your midbass, fill that first. Run the 6.5 up to 400 to meet your mid, similarly up the midrange to five. Cut 200&315 a chunk and a couple of clicks from 1.25 to 3.


I can't stand the way it sound's when I run the 6.5 up that high, that dip at 300-400 is from the mid. I don't know why the mids roll of at around 80-90hz, sub roll's off right at 60hz, so I should raise the sub to 80-90hz? and keep the midbass at 60hz?


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## gu9cci (Mar 28, 2011)

Anyone can pointed me to the best and easy use calibrated microphone for rew?


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## Jscoyne2 (Oct 29, 2014)

gu9cci said:


> Anyone can pointed me to the best and easy use calibrated microphone for rew?


Umik1

Sent from my SGH-T999 using Tapatalk


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## Justin Zazzi (May 28, 2012)

Try Cross·Spectrum Labs - Sound | Vibration | Engineering

They offer two different USB powered, calibrated microphones. Both are good from what I hear.

I've used the non-usb-powered one for a few years with great success.


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## gu9cci (Mar 28, 2011)

Just ordered the umik from madisound
Cross spectrum are out of stock


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## Babs (Jul 6, 2007)

gu9cci said:


> Just ordered the umik from madisound
> Cross spectrum are out of stock



That'll work. Can always send to Cross Spectrum if you wanted a full camibration file library. 


Sent from my iPhone using Tapatalk


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## Hoptologist (Sep 14, 2012)

Rrrrolla said:


> If you're getting the null with "normal" phase, and you haven't changed anything, anything, sounds like your new sub is wired backwards, no big deal, either reverse the polarity of the wiring to your sub, or leave it "inverted" for normal listening, and put the phase "normal" for finding your dips. Inverting phase means flipping polarity. Your new sub might have its polarity labeled incorrectly, I've seen that before.


You were right, sub was wired backwards.


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## Hoptologist (Sep 14, 2012)

Just did a series of measurements trying to get my sub in phase with my mids using the finding-the-deepest-null-when-phase-is-inverted-and-then-flipping-phase-to-normal method again, like I successfully did before with the DD 3515. The numbers in the legend correspond with time-delay inches in my BitOne software for the sub channel when phase is inverted.

Here is 78-120Hz, my crossover region. I inverted phase and played with time alignment in the BitOne. Started at 42" on the sub, and gradually made my way to 0". As you can see, 0" gave me the deepest null (bottom purple) and then when I flipped phase to normal, turquoise gave me the highest summing (top line). 










But this had a negative effect in my 55-75Hz range, as you can see here. What gave me the best summing at my crossover region, gave me my lowest output in my 55-75Hz region. Is this normal, or is something not right here? 










And here is an enlarged look at these regions, with some time alignment measurements omitted for cleanliness. 










1. What gives? It seems like I'm out of phase between 55-75Hz, even though I found the deepest null at the crossover point using this method.

2. Should I cut 60-70Hz on my mids so that area doesn't interact with the sub as much?

3. Should I try a different LPF on the sub / HPF on the mids?

4. Should I just pick a time-delay measurement that gives me the best average of both of those regions?

5. Just noticed my graph isn't to 5db increments. Sorry.


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## Drop11 (Jul 4, 2016)

In time is in time. Phase is phase. While you can use ta to correct for phase they are not the same thing. 

Ideally you want the sub to have correct timing and correct phase. Using Ta to get phase is a bandaid. 

It leaves things out if correct timing.

If you have a way to tune phase separately (I'm using the phase adjustment on my amp) in less than 180° increments use a tape measure to get a good reading on the sub and correct the rest with phase.

Also something most people look over. 
With the crossovers shifting phase if you can't adjust your phase independently other than 180°s you can try moving your front stage way out in time. Then put your sub a zero delay and use the invert method to find the first null. The is will give the sub a full cycle adjustment and make up for the 360° phase shift you see with steep crossover slopes.
It may clean some of that up.


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## Hoptologist (Sep 14, 2012)

I changed my LPF to 90 Hz @ 36dB/slope. Was able to find a MUCH deeper null at 20" TD on the BitOne software (a -45dB null compared to my previous -20dB null), and when I flipped phase to normal, I no longer lost any output from the sub's baseline between 55-75 Hz. Pretty happy for now. My mids still need EQ, but I'll probably wait until it gets cooler or I get a new DSP with greater control.


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## Drop11 (Jul 4, 2016)

I give up. How in the hell do I get house curves to show up in the rta window?
I've dl'ed a few curves from you guys that I'd really like to try. I can find them under the house curves tab bit cannot find a way to see them on the rta or eq. Very frustrating.


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## Drop11 (Jul 4, 2016)

This was hand tune from this last week.



By no means perfect but it sounded nice enough.

I spent most the morning today digging around in REW'S eq window.
It almost makes me sad. REW makes tuning trivial. 
Take a measurment, push a button then punch the filter settings into your dsp. 
It completely zaps the fun out of it.

I used a new curve today.
20hz flat to 60hz. 60hz sloped to 160hz. 160 flat to 2khz and 2khz rolling off 1.8 db per octave.

It's BORING. Good impact, super clear. On the focal utopias it just sounds stale. No character at all. As far as pure sq I'm sure many would love it. For live music I like it a lot but most of what I listen to is not live music. It's gritty electronic. 
Due to the natural limitations of the drivers I'm using its also very quite for my taste. I get right around 90db before my mids get mad at me. I like to listen between 100 and 110 db. 
Let's just ignore that for now.
I'm looking for a more fun curve to try. Im looking for something with more impact, a heavier low end and more in your face top end. 
If you guys have any suggestions I'd love to try them out.


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## Drop11 (Jul 4, 2016)

Also what the hell is that 10hz? It shows up on everything I measure. Can I kill it in the calibration file by bottoming out everything below around 15hz?


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## TwistdInfinity (Jun 7, 2015)

Well I'm into my first set of measurements for my install (3 way front, tweeters in sails pointing at top of opposite b pillars, mids in a pillars pointing at top of opposite b pillars, mid bass's in stock lower door positions facing straight in, subs in rear quarter panels facing straight in)

Most of my responses look pretty good except my drivers side midbass. There's a massive hole that I can't see any way of fixing.

This is already the quietest of all my drivers so I don't want to set the target curve lower and eq the rest of the driver down to match the curve, cause I'll have to lower all my drivers by 15+dB to match.

I guess for an SQ comp where listening levels are kept low it would work, but for daily pumping of the sound system it'll be way too quiet.


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## rlee777 (Apr 28, 2009)

Drop11 said:


> I used a new curve today.
> 20hz flat to 60hz. 60hz sloped to 160hz. 160 flat to 2khz and 2khz rolling off 1.8 db per octave.
> 
> It's BORING. Good impact, super clear. On the focal utopias it just sounds stale. No character at all. As far as pure sq I'm sure many would love it. For live music I like it a lot but most of what I listen to is not live music. It's gritty electronic.
> ...


I used the same house curve in my tuning and know exactly what you mean by "boring". However, I do notice that this flat response sounds natural and does not favor any specific genre of music. Sounds the same at different volume levels (hard to explain this, but without response peaks, it sounds very "linear") and I find myself listening at higher volume than before -- can be startling when I start the car again! 

Beginning to like this tune. Give it some time. Flat response is not that exciting, but is more accurate.


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## Drop11 (Jul 4, 2016)

It growing on me. It's not far off from what I'm used to. Putting a steeper hp filter on my mids helped a lot. It needed some cleaning up down low. Its so damned deep. I know a lot of people would like this but it takes a lot of getting used to.
Everything sound way out on the hood and I'm used to the stage being on the dash. I'm not sure I like this. I like that up close sound. I'll likely push the roll off to 5khz instead of 2khz. That will help a lot.


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## Babs (Jul 6, 2007)

Drop11 said:


> Everything sound way out on the hood and I'm used to the stage being on the dash. I'm not sure I like this. I like that up close sound.



Hahahaha funny how many folks struggle to achieve that. Achieving a stage that's wider and deeper than the cabin is a glorious thing when done well. 



Sent from my iPhone using Tapatalk


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## Drop11 (Jul 4, 2016)

Babs said:


> Drop11 said:
> 
> 
> > Everything sound way out on the hood and I'm used to the stage being on the dash. I'm not sure I like this. I like that up close sound.
> ...


In my truck it's easy. Off axis tweeters in the corners of the dash, roll everything off at about 2db per octave at 2khz. 
I flattened it out to 5khz to brighten it up and bring it a little closer. I like this a lot better. More detail. 
Now width. I got nothing. Thinking about adding some 3inch mids and playing with the angles to see if I can get something going.


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## lizardking (Nov 8, 2008)

This was a cool thread. So if I'm understanding the author of REW, we should be using the RTA versus the Spectrum mode for measuring? We use uncorrelated pink noise for full frequency measuring ( all drivers ) and correlated pink noise for single driver measurements? I also see he mentions "periodic pink noise" when using the RTA function in REW. Is that per driver measureing only?


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## dengland (May 25, 2014)

lizardking said:


> This was a cool thread. So if I'm understanding the author of REW, we should be using the RTA versus the Spectrum mode for measuring? We use uncorrelated pink noise for full frequency measuring ( all drivers ) and correlated pink noise for single driver measurements? I also see he mentions "periodic pink noise" when using the RTA function in REW. Is that per driver measureing only?


Did you ever get an answer outside of this thread?


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## GCVIC (Dec 29, 2015)

Im just new to rew and rta, and will continue to read much more material, including this thread, but in the meantime I am posting my very first averaged measurement (6 measurements w/ umik-1) below - in case someone can please provide any initial feedback/observations - thank you.


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## alligatorman (Sep 7, 2010)

GCVIC said:


> Im just new to rew and rta, and will continue to read much more material, including this thread, but in the meantime I am posting my very first averaged measurement (6 measurements w/ umik-1) below - in case someone can please provide any initial feedback/observations - thank you.


Get the SPL up to 75db (turn up the volume) and re-measure. Then post up results!

sent from the toilet


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## Jscoyne2 (Oct 29, 2014)

GCVIC said:


> Im just new to rew and rta, and will continue to read much more material, including this thread, but in the meantime I am posting my very first averaged measurement (6 measurements w/ umik-1) below - in case someone can please provide any initial feedback/observations - thank you.


Show what your driver crossover points are. Per side.









Kinda like that. Where one rolls off and another picks up

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## lowcel (Dec 28, 2014)

This was getting ready for the RTA at finals.


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## valow (Dec 24, 2016)

I'm not sure how much this thread will revive, but I wanted to get some feedback on a measurement I took of my drives side midrange. Polk Audio DB 6501. Ford F150 with PAC Audio FD-21 attached to the head unit. TOS back to a JL TwK D8. This was a measurement I took and it looks pretty hairy to me. Any insight? Also, nothing in the vehicle is deadened and I know that this driver will be a pain to tune. The top line is with a flat EQ..bottom was me trying to EQ it. Don't laugh.


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## brumledb (Feb 2, 2015)

How much smoothing are you using on that graph?

The easiest thing to do is create a house curve and then let REW generate your eq cuts and then you just simply plug them into your DSP. 

http://www.diymobileaudio.com/forum/technical-advanced-car-audio-discussion/206881-jazzis-tuning-companion-room-eq-wizard.html


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## valow (Dec 24, 2016)

brumledb said:


> How much smoothing are you using on that graph?
> 
> The easiest thing to do is create a house curve and then let REW generate your eq cuts and then you just simply plug them into your DSP.
> 
> http://www.diymobileaudio.com/forum/technical-advanced-car-audio-discussion/206881-jazzis-tuning-companion-room-eq-wizard.html


Hi, thanks for the response. That is a 1/12 octave curve. I'll have to look in to what you suggested, that sound awesome and much easier than sweeping ear to ear with pink noise 1000 times.


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## valow (Dec 24, 2016)

brumledb said:


> How much smoothing are you using on that graph?
> 
> The easiest thing to do is create a house curve and then let REW generate your eq cuts and then you just simply plug them into your DSP.
> 
> http://www.diymobileaudio.com/forum/technical-advanced-car-audio-discussion/206881-jazzis-tuning-companion-room-eq-wizard.html


Holy moly you saved me. I have the house curve built, but I'm using 12 db slopes on my drivers. I'll probably change them up to 24 and then pull data in to REW using Pink Noise again. After that I'll tune away and report back. Super excited to get this going.


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## Babs (Jul 6, 2007)

I've done both on-the-fly EQ by measuring, and by plugging in the predicted REW EQ trims.. I think for me anyway I've had to use a combination of that. If I go with some parametric EQ predicted trims from REW, I still have to remeasure and assess how they did. The predictions aren't necessarily perfect in real world when you plug them into a typical IIR-based DSP, plus in car things get wonky due to the acoustic environment.. So measure, EQ, measure, EQ.. Iteratively. 

.. My new theme here being: Limited software, limited DSP and wonky car acoustic environment all combined assures that you cannot just trust in a expected response result from what REW gives you. Trust with skepticism, try and then verify. 


Sent from my iPhone using Tapatalk Pro


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