# Help me tune my 2-way active setup



## Ziggyrama (Jan 17, 2016)

Hi guys,

I am starting to tune my active setup. Car is 2011 STI hatch. It is a 2-way using Focal ps165fx, typical install, mids are in the doors at the bottom, tweeters are in the sail panels, sub is in the trunk, sealed enclosure. I am using Hanatsu's measuring guide to get started:

http://www.diymobileaudio.com/forum...first-timers-guide-measuring-your-system.html

I started with time alignment based on distances. I have it more or less dialed in, it may need final tweaks, overall it should be close.

I am using the following for the crossovers:

subwoofer: LR4 LPF 80Hz
mids: LR4 BPF 80Hz - 3KHz
tweeters: LR4 HPF 3KHz

I took my first set of measurements to set the levels between left and right channels. EQ is flat on all channels. See graph below. As you can see, it is a mess. It sounds like a mess too.

- I think I need to bring the tweeters down by about 10db to get them roughly at the same level as mids. Does that sound right?

- the left mid has these 2 large swings at 120Hz and 300Hz. Should I attempt to cut them down? 

- the big dip at 600Hz, does this look like something I can correct by boosting or do you think this could be a TA issue creating a cancellation?

I will probably start with the JBL curve but before I do that, I need to get this system tamed before I start targeting that. Any other thoughts?


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## Mless5 (Aug 21, 2006)

If it were me, I would try cut peaks before you fix dips, so 150 and 300 humps is what I would address first. Than try to fix 600hz and 6K dips some so they aren't that bad, bump the crossover to 12db and create a gap between mid high pass and sub low pass.


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## SkizeR (Apr 19, 2011)

figure out your target curve, eq each speaker within its bandpass to match within reason. knock down that massive 300hz peak on the one mid, id not worry about the 600hz dip for now, and flatten everything else out to match the curve you want. id leave the crossovers how they are. matched crossovers with LR4 slopes will create a flat summed response and has a total of 360 degree phase shift as opposed to 180 degree total phase shift of 12db slopes.


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## Justin Zazzi (May 28, 2012)

Good advice so far.

If you would like some help with the target curve aspect of tuning, I made a tool for Excel for this purpose. Check the link in my signature below (tuning companion) and let me know if you have any questions about using it. I haven't done a full how-to manual yet, so it might not be completely intuitive yet.


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## Ziggyrama (Jan 17, 2016)

Thanks for the replies guys. I appreciate your time.



SkizeR said:


> figure out your target curve, eq each speaker within its bandpass to match within reason. knock down that massive 300hz peak on the one mid, id not worry about the 600hz dip for now, and flatten everything else out to match the curve you want. id leave the crossovers how they are. matched crossovers with LR4 slopes will create a flat summed response and has a total of 360 degree phase shift as opposed to 180 degree total phase shift of 12db slopes.


Makes sense. I created a JBL curve file and loaded it into REW. I will start with that and see how it sounds. I keep reminding myself, should be 1st cutting, then addressing the rest. I chose LR4 exactly for the reason that you described. It puts the signals back into phase so I do not have to worry about aligning the phase due to xover shift. Also, from my research, having a steep fall off is desirable to eliminate cancellations and not push the speakers into a bad situation where it will distort.



Jazzi said:


> If you would like some help with the target curve aspect of tuning, I made a tool for Excel for this purpose. Check the link in my signature below (tuning companion) and let me know if you have any questions about using it. I haven't done a full how-to manual yet, so it might not be completely intuitive yet.


Thanks! I already have your spreadsheet loaded, which I used for dialing in TA. It was very helpful. The instructions in it are pretty self explanatory and I had no problem following it. Props to you for creating it, it is very good.

Question about LR4 crossover...the phase shift is non-linear. The low passed signal experiences an increasing signal phase shift as it approaches the crossover point hitting -180d while the high passed signal sees a lead, approaching +180d phase shift. Although the result is a full 360d shift, thus getting signals back into phase, doesn't the reproduction itself see a phase shift between the frequencies where low passed signals are basically playing 1 full cycle before the high passed frequencies? Wouldn't that result in some kind of audible misalignment? If so, would one adjust for this with TA to delay the high passed signal by 1 full cycle to align it back with low passed signal? You know, getting the vocals to play in sync with kick drums 

Good read on this: http://www.rane.com/note160.html


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## Ziggyrama (Jan 17, 2016)

This morning, before I saw your posts, I did some tuning to get the tweeters level matched so that they don't sound so piercing. They were playing way too high with respect to mids which was making my ears bleed. Just by level matching the tweeters, the overall sound improved significantly. It's no where near respectable yet but a step in the right direction. Next, I will look at cutting some of those peaks down and see how it sounds overall.


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## Ziggyrama (Jan 17, 2016)

Ah, another question about electronic vs. acoustic crossover:

from what I gather, the electronic crossover point should be chosen based on the characteristics of the driver itself taking into consideration size, it's resonant frequency and probably some other factors. I have seen references that the acoustic crossover is what you should focus on but doesn't that mean that you may push the speaker into a range that it just isn't good at playing? Why focus so much on the acoustic crossover so much? As long as the response is sufficient and both drivers are in their happy zones, why fixate on the acoustic frequency that we want to see on a graph?


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## Justin Zazzi (May 28, 2012)

Ziggyrama said:


> Question about LR4 crossover...the phase shift is non-linear. The low passed signal experiences an increasing signal phase shift as it approaches the crossover point hitting -180d while the high passed signal sees a lead, approaching +180d phase shift. Although the result is a full 360d shift, thus getting signals back into phase, doesn't the reproduction itself see a phase shift between the frequencies where low passed signals are basically playing 1 full cycle before the high passed frequencies? Wouldn't that result in some kind of audible misalignment? If so, would one adjust for this with TA to delay the high passed signal by 1 full cycle to align it back with low passed signal? You know, getting the vocals to play in sync with kick drums
> 
> Good read on this: Linkwitz-Riley Crossovers: A Primer


I think you're asking about the audibility of group delay. This phenomenon hasn't been studied in great detail, but there are a couple of numbers we can work with. Check the link below and look at section #5 Group Delay. I'm not sure where the numbers for group delay audibility come from, but I've seen them in many different places so it's likely the result of some test.

Phase, Time and Distortion in Loudspeakers

In short, when two speakers are playing two different frequencies above and below the crossover region, it is very difficult to hear small differences in time or phase. Also, to correct the anomaly like you suggest using time alignment could make the relationship at any one frequency perfect, at the detriment to all other frequencies. By leaving time alignment out, you can keep the 360 degree phase relationship at all frequencies, which is greatly preferred.

edit: I think I found the research paper for group delay audibility:
Blauert, J. and Laws, P "Group Delay Distortions in Electroacoustical Systems" 
Journal of the Acoustical Society of America
Volume 63, Number 5, pp. 1478-1483 (May 1978)


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## Justin Zazzi (May 28, 2012)

Ziggyrama said:


> Ah, another question about electronic vs. acoustic crossover:
> 
> from what I gather, the electronic crossover point should be chosen based on the characteristics of the driver itself taking into consideration size, it's resonant frequency and probably some other factors. I have seen references that the acoustic crossover is what you should focus on but doesn't that mean that you may push the speaker into a range that it just isn't good at playing? Why focus so much on the acoustic crossover so much? As long as the response is sufficient and both drivers are in their happy zones, why fixate on the acoustic frequency that we want to see on a graph?


Choosing a crossover point can be based on many things. For a high-pass filter some things to consider are protection against over-excursion, protection from thermal damage from too much energy in the low frequencies, and avoiding distortion in the frequencies near and below the speaker's resonant frequency. For a low-pass filter some things to consider are to prevent the speaker from playing into the cone-breakup frequencies and also prevent it from beaming at higher frequencies.

As for acoustic vs electronic measurements, I'm writing an article on this right now and wish it was ready for you. If you think of subtraction of two numbers (like what you learned in elementary school) as a 1-dimensional mathematical operation, then you can also think about a crossover filter as a 2-dimensional mathematical operation because it requires both the amplitude and the frequency of a signal to be used.

So if the output of your crossover "equation" is a frequency and phase response that looks like the graphs we see all the time, then the input of the crossover equation is going to be: (1) the natural response of the speaker and (2) the effects of the enclosure and environment it is in and (3) any electronic filters applied to the signal before it reaches the speaker (including all EQ, crossover, shelf, notch, and other filters).

Since (1) and (2) are fixed, the only way to get the output of the crossover equation to match the desired textbook alignment is to modify (3) the electronic filters. Also since every speaker/enclosure/environment combination is completely unique, there does not exist any one particular electronic filter that can manipulate the acoustic response to meet your chosen crossover alignment. So, you need a unique combination of crossover and EQ filters and simply setting an LR4 on your processor for all your channels is a step in the right direction, but not what you really want. Even the left and right channels in your car need a different set of filters, which is why independent left and right crossovers and EQ is so useful.

This is *exactly* why I built the Excel spreadsheet, so you can take the speaker/enclosure/environment combination that you have and measure it with REW, then compare it to the ideal response that my spreadsheet spits out, and use the EQ module of REW to help you craft (3) the electronic filters to make up the difference between the two.

The result is an acoustic frequency response that matches the filter alignments, and as such, will have a matching phase response that ensures the corresponding high-pass and low-pass filters will sum together properly without any anomalies.


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## Ziggyrama (Jan 17, 2016)

Jazzi, thanks for all that info. I will go through the links that you posted.

As for the EQ, I think like get it now. What I missed is the fact that the xover point is essentially a point where 2 curves intersect and if they do not cross at the desired point, it means the curves themselves are not right. I get it now. I experimented with the xover calculation part and it did produce somewhat expected result for my sub. I do have an oversized amp for my sub which I think throws off the numbers. I turned the gain down to prevent it from reaching full power so I think I should be safe. That being said, I think most people don't have my problem so your sheet is very useful in helping people dial in safe settings.


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## Justin Zazzi (May 28, 2012)

What was the unexpected result for your sub? Can you post a screenshot of the numbers you typed in so I can replicate the odd result?

I too have much more power going to the sub than my front stage and that's not really a bad thing. Since we want our bass and sub-bass to be much louder than everything else, it's required. So long as the crossovers for the sub-to-midbass drivers are good, and the frequency response is a nice gentle increasing curve, then you can feed lots of power to the sub.


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## Jon225 (Mar 21, 2011)

What processor are you using.


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## Ziggyrama (Jan 17, 2016)

Jazzi said:


> What was the unexpected result for your sub? Can you post a screenshot of the numbers you typed in so I can replicate the odd result?
> 
> I too have much more power going to the sub than my front stage and that's not really a bad thing. Since we want our bass and sub-bass to be much louder than everything else, it's required. So long as the crossovers for the sub-to-midbass drivers are good, and the frequency response is a nice gentle increasing curve, then you can feed lots of power to the sub.


I double checked the results for the sub and they look right. I think I remembered it wrong. I believe I tried to plug in numbers for the tweeter at some point and the results looked wrong. I also just re-read the disclaimer next to the calculator and it clearly states that the tool will not work for dome tweeters......which is what I have. So, the weird numbers was pilot error, PEBKAC.

For reference, this is what it works out for my Focal sub P25F:












Jazzi said:


> What processor are you using.


I'm using Zapco Z8.


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## Justin Zazzi (May 28, 2012)

Looks like you entered all the parameters for the woofer correctly, but you are trying to use 0.68 cubic feet instead of 19 liters for the enclosure volume. It will work much better if you make that change. I would also lower 750 watts to 600 unless you are really wanting to give the woofer that much power! (only rated for 300w rms afterall).

With those changes the tool recommends a 2nd-order subsonic filter at 31hz, which seems about right.


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## Ziggyrama (Jan 17, 2016)

Jazzi said:


> Looks like you entered all the parameters for the woofer correctly, but you are trying to use 0.68 cubic feet instead of 19 liters for the enclosure volume. It will work much better if you make that change. I would also lower 750 watts to 600 unless you are really wanting to give the woofer that much power! (only rated for 300w rms afterall).
> 
> With those changes the tool recommends a 2nd-order subsonic filter at 31hz, which seems about right.


Doh! I forgot to convert to liters on the enclosure volume. Another mistake on my part.

Regarding the power number, so this parameter is not clear cut. I put in the max power that my amp can do based on subwoofer's impedance. My interpretation was that this is the max power that the sub could see so using that would calculate the safest setting. Sounds like this should be the max power setting that the speaker can handle?


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## Justin Zazzi (May 28, 2012)

Well the safety of the woofer depends on both excursion (which my tool helps with) and thermal overload (which you must be careful of). Most people can get away with using about double a woofer's rms rating to play high dynamics and peaks of musical material, but not long, consistently sustained bass notes. Since the rms rating of that woofer is only 300w, that turns into about 600w for peak material. While 750w won't outright destroy it immediately, it does make it less likely the woofer will survive if you push it hard enough.

That's my line of thinking anyways.


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## Ziggyrama (Jan 17, 2016)

Hi guys,

an update. I took my 1st pass at eq'ing each driver. I never used autoEQ in REW so I tried to see what kind of results it would produce. Few things:

- REW is a bit finicky as far as the filters and you have to get those right or the numbers will come out bogus

- REW produced around 13 points for the mids and 9 for the highs, which was a problem for me since I can only do 10 PEQ bands. I had to combine some of them, to fit into 10, aiming at producing roughly the same curve.

See below for results. Target level is 90dB. I did the sub manually, which I think is the closest to the target curve. The other drivers are still off, overall, the levels are lower than they should be. I think autoEQ is a good idea but it didn't seem to produce the outcome I was hoping for. Perhaps I didn't do it right. The good news is, I can now compare the adjustment to the measured effect to get a sense as to how the curve is affected by the changes. For example, that 600Hz dip is probably not fixable, unless I move the mids to another place, maybe. 

Sound wise, it actually sounds not bad. The imaging is pretty good, I can hear true stereo for the 1st time, with details coming through like never before, which is getting me excited about this build. The staging is off though, pulling to the right, which is surprising since the left side shows higher FR than right, but I suspect this is an effect of the right tweeter coming through. Bass response is pretty good, although I think mid bass is lacking a litttle.

Let me know what you think.


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## Mless5 (Aug 21, 2006)

Slide your highpass on woofers down a bit. You may have to move subwoofer low pass down a bit as well to compensate, otherwise it may start to sound muddy.


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## SkizeR (Apr 19, 2011)

Mless5 said:


> Slide your highpass on woofers down a bit. You may have to move subwoofer low pass down a bit as well to compensate, otherwise it may start to sound muddy.


depends. as long as its eq'd right it will sound fine. as opposed to playing the mids to low and over excuting (is that a real word? lol) and introducing distortion


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## Ziggyrama (Jan 17, 2016)

I had another look at my measurements as the levels don't look right after EQing. The latest plots are whack, as far as levels, I will post an updated plot. The right midrange is actually not too far off the targets, the left midrange (next to the driver) is where I will have my work cut out for me. New graphs coming soon.


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## Ziggyrama (Jan 17, 2016)

Been working on the mids and after about 8 revisions, I think I got them dialed in fairly well. They sound pretty good, still need to correct some issues. 

- tot sure if I can sort out the 600Hz dip on the right, I will have to see if it ends up responding to EQ.

- I am getting too much bass from the right which extends into sub territory. Not sure why, given that I already cut that area pretty hard.

- See if I can bring up some of the roll off to match the curve a little more, although it sounds pretty good already

Mid left and right together:










Mid left vs. target curve:










Mid left DSP settings:










Mid right vs. target curve










Mid right DSP settings:


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## bnae38 (Oct 3, 2015)

Damn, wish i could get midbass response like that... 

Jw.. where are they located?


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## Drop11 (Jul 4, 2016)

bnae38 said:


> Damn, wish i could get midbass response like that...
> 
> Jw.. where are they located?


I know right. I ran those speakers and min rolled off hard above 100hz. My utopias do the same. I saw it on the first page. His midbass was higher than anything else without eq. Grrrrr.


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## bnae38 (Oct 3, 2015)

That and no modal dips, although resolution looks to be pretty low.


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## Ziggyrama (Jan 17, 2016)

I still have a dip in my right channel that I need to do something about, although it isn't very severe.

I am using psychoacoustic smoothing which is doing variable smoothing, while adding to weighing to the peaks. I have also used variable smoothing, very similar results. From REW:

_Psychoacoustic smoothing uses 1/3 octave below 100Hz, 1/6 octave above 1 kHz and varies from 1/3 octave to 1/6 octave between 100 Hz and 1 kHz. It also applies more weighting to peaks by using a cubic mean (cube root of the average of the cubed values) to produce a plot that more closely corresponds to the perceived frequency response._

I did a lot of work to treat my doors, to improve the responses and efficiency. About 50% of the inner door has sound deadening, with double layer directly behind the speaker. Then I applied CCF to decouple the surfaces and seal off the door. Then, on top of CCF, I added MLV to block the sound from coming in or out. Final touch, I added transducer rings to guide the waves out into the cabin. Deadening, CCF and MLV are a real deal, they really work and I highly recommend doing that. The rings, I don't know how much they help, I am pretty sure they don't hurt anything. The OEMs use them and they don't just spend money for nothing so I am betting there is some effect from that.

Overall, the mids play with really good authority. When the guitars hit hard on the intro for Soilwork, you can really feel it. It sounds really good. Funny, even the OEM speakers sounds half way decent after door treatment.

I am currently focusing on the tweeters and they are proving to be challenging. They have a lot of zing to them and in high frequencies, small adjustments seem to have a larger effect on response so little goes a long way. I am getting close, the changes I did yesterday sound pretty good but I need to take measurements. I will post that too along with the DSP settings.


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## bnae38 (Oct 3, 2015)

Cool. Yeah i went the home depot route with "mlv" and denim looking foil backed decoupler. Worked, but could have been better.. . Cld went in first of course. 

I have fast rings installed too.

Think my biggest problem may be a large hole that is not sealed in the front doors, it is more or less pinched shut with the mlv/decoupler barrier when the cards are on. The cards assemble in such a way that the cup-holder area is deeper than the rest, so a hard seal was not going to be easy if i wanted to keep my windows working..

Good work!


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## Ziggyrama (Jan 17, 2016)

Well, I have been tuning the setup on and off for the last few months. I had a major problem with staging where sound was pulling to the right. I could not figure out why this was happening. After following this thread, based on sqnut's advice about T/A measurements, I remeasured, reset my settings and that alone made a huge improvement. So, now I am back to tuning FR. Below is where I am at now. 

All crossovers set to LR4
mids HPF: 80Hz
mids LPF: 2700Hz

Smoothing 1/6oct

I suspect the nulls on both sides around 150Hz are modal. The one that puzzles me a bit is the big dip on passenger side around 600Hz. The null does respond to boosting somewhat but I am weary of boosting that area that much to level off the response. What do you think is happening here?










The FR doesn't look the best but it actually sounds pretty good, oddly enough. The imaging is very good, wide staging, vocals in the center of the car, middle of the windshield. I think T/A fairly well dialed in.


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## SkizeR (Apr 19, 2011)

one tweeter is much hotter than the other.. thats my main concern


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