# Sticky  System Tuning



## Eric Stevens

*System Tuning Updated 10/8/2014*

Updated 10 8 2014
Tuning
This will be a continuing and updated thread but enough is here to start. I can answer questions or clarify the text as needed based upon your questions. This will not be a post aimed at basic audio education so you will need to have a good understanding of the basics and some tuning experience.

The same methods and process are used to tune any system regardless of speaker type. So if your not using horns, substitute tweeter, or mid and tweeter as necessary or needed. I don't cover the use of rear fill as I have always gotten my best results without it.

Not necessary but an RTA (real time analyzer) is a very useful tool in tuning any audio system and is high recommended for best results. Final settings are always made by, or confirmed by ear, because it does not matter what the RTA looks like. I can tell you that when the RTA looks bad and the system sounds good, its usually not as good as it could be. 

The steps are as follows:

1- Set beginning crossover settings

2- Set beginning levels 

3- Set phase/polarity for best sound quality and staging.

4- Revisit steps #1 and #2 readjusting as necessary.

5- Equalize the system, best to do left and right separate but OK to do them together.

6- Listen and tweak by ear. 

7- Revisit steps #4 and #5 then #6 until happy

Notes, thoughts and details:

#1 Details: To properly execute step #1 it requires that you plan your system correctly. You should know the strengths as well as the limitations of the drivers you have selected or are working with and set preliminary crossover settings. 

#2 Details: Step #2 requires starting with proper system gain setup. The theory and instructions for proper gain setting are a subject that requires much explanation so I will only skim over the subject. This is done with the weakest link (lowest output) in the system set to maximum output level with volume set near but still below maximum output from the source unit. Then adjust the other levels to achieve proper tonal balance from each of the speakers in the system. 

*I will usually add a little higher level (+2 to + 6dB) to the speakers that need the most EQ so I can cut only with my EQ.
**Try to keep amplifier input gains as low as possible

#3 Details:

I like to get the center as strong and centered as possible using polarity/phase and levels before applying signal delays to the system. 

Process to do this is: Use the IASCA CD and track #3 which has a spoken voice in phase and out of phase. Start by reversing polarity of one midbass and one horn both on the same side of the car. Start my muting the midbass and listen to the horns only and confirm that the spoken voice is more centered and coherent when in phase, then mute the horns and listen to just the midbass and confirm that the spoken voice is more centered and coherent when in phase. Next using track 12 with the three voices listen to height of the voices and if low reverse polarity/phase of BOTH horns together. Listen again to confirm that the stage is highest in this position. At this point you should have a strong center image and the position and height of the stage and center image should be good or better. Signal delay would be the next step to align the midbass to the horns. We want to delay the midbass to align with the horns since the horns are the farthest driver from the listening position. The most effective way to do the time alignment by ear I have used is to use one of the tracks on the IASCA CD with a spoke voice and balance or mute so that only the left channel is playing and delay the midbass driver in small increments until the voice is as high as possible. I will then copy this delay setting to the right side midbass driver.

Next tuning step is to use an RTA and EQ FR separately for left and right channels. I recommend that you move the microphone in a figure 8 pattern where your head would be during listening and take 10 second averages and EQ based upon the measured 10 second average. You will EQ the right side with the mic in the right seat head location and the left with the mic in the left side seat location. When doing this separate LR I only work on 200 Hz and up and shoot for a flat response, be careful of dips in the 400 to 800 range as they are typically caused by destructive cancellation and while you can make the RTA look flat it certainly will not sound that way. I leave this area alone if it does not respond to EQ adjustments I.E. you boost 630 Hz +6dB but only get an increase of +2dB.

After EQ is done for LR separately bring both together and do a 10 second average in the drivers head position and bring down any peaks that develop above 200 Hz and don’t boost any dips that develop. then tune the bottom end with a smooth rising response. The rise can begin anywhere from 125 to 250 Hz depending on the system and typically will rise to minimum of +6dB over the broad portion of the curve to more than +12dB.

In the 400 - 800 range with the RTA do like I say and if there is a problem in the lower midrange the first thing to do is see if there are any bands with boost in that range, and if so bring them back to zero and re listen. It is an area like the sub bass that must be done by ear.

Details related to tuning for best sound stage with realistic focused images.
It helps to understand how we aurally localize images within a sound stage, and how the tools we tune with can correct, affect or influence what we hear when tuning. There are three major forces we have to deal with: 
1-amplitude or loudness 
2- Phase 
3- Time arrival.
All three have effects throughout the whole audio spectrum of 20Hz to 20Khz but in many areas there is a dominate force, and the other two have less of a roll in where images are placed within the sound stage. To simplify the explanation and help those less technical I will divide this into three frequency areas where each force is the dominate one. Within each frequency range you can use more of one force to overcome a problem or deficiency in another. I will say this though, your results may vary  
1- High frequencies are dominated by amplitude. Second strongest force is time and least is phase.
2- Mid-range is marginally dominated by arrival time with Amplitude and phase are what I would term very close depending on the actual spectrum of frequencies being covered.
3- Low frequency is dominated by phase followed by amplitude and then time.




Eric Stevens


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## JoshHefnerX

Sub'd for this one!

Quick question. On the RTA how important are trying to get rid of small tight notches or peaks? Or is it best to tune w/ a certain amount of smoothing so you're not fighting 'the little stuff' and driving yourself crazy?

BTW I've got your horns in and they sound great!

Josh


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## Eric Stevens

JoshHefnerX said:


> Sub'd for this one!
> 
> Quick question. On the RTA how important are trying to get rid of small tight notches or peaks? Or is it best to tune w/ a certain amount of smoothing so you're not fighting 'the little stuff' and driving yourself crazy?
> 
> BTW I've got your horns in and they sound great!
> 
> Josh


The little stuff matters on 1/3rd octave. The thing to watch is if the peak or dip repsonds to the adjustments in a linear fashion. if you boost a frequency by 3dB and it only increases 1dB there is a cancellation and it is better off left alone usually.

Eric


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## fcarpio

Subbed.


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## Souths1der

I would like to hear more on #1 and if you have some guidelines for starting crossover settings.

Also, could you expand on your process for #2 on your list?


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## ErinH

Eric Stevens said:


> The little stuff matters on 1/3rd octave. The thing to watch is if the peak or dip repsonds to the adjustments in a linear fashion. if you boost a frequency by 3dB and it only increases 1dB there is a cancellation and it is better off left alone usually.
> 
> Eric


I hope people pay attention this. So, I'm quoting it.


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## Eric Stevens

Souths1der said:


> I would like to hear more on #1 and if you have some guidelines for starting crossover settings.
> 
> Also, could you expand on your process for #2 on your list?


To start on #1 requires that you plan your system correctly prior to starting. You should know the strengths as well as the limitations of the drivers you have selected or are working with. 

#2 requires proper system gain setup. it is done with the weakest link (lowest output) in the system set to maximum output level with volume set near maximum. Then adjust the other levels to achieve proper tonal balance from each of the speakers in the system.

I will usually add a little higher level to the speakers thatneed the most EQ so I can cut only with my EQ.

Eric


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## Kevin K

Very good info


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## fcarpio

ErinH said:


> I hope people pay attention this. So, I'm quoting it.


Good point, but this should be less of an issue if you are doing one side at a time, right?


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## ErinH

you still have a reflecting environment. modal issues and combing issues can affect a single speaker in any natural environment (yes, any... even the ground in a free-field park will cause a cancellation null ).


you've got different issues with speakers. they can cancel out due to lobing and they can have cancellation due to the environment (windows, seats, dash, etc).


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## fcarpio

ErinH said:


> you still have a reflecting environment. modal issues and combing issues can affect a single speaker in any natural environment (yes, any... even the ground in a free-field park will cause a cancellation null ).
> 
> 
> you've got different issues with speakers. they can cancel out due to lobing and they can have cancellation due to the environment (windows, seats, dash, etc).


Yeah, I see it happening. Rear seat up vs. rear seat down makes a difference in my RTA curve.


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## Eric Stevens

fcarpio said:


> Good point, but this should be less of an issue if you are doing one side at a time, right?


What Erin says in a later post also.

When you bring both sides together i cut the peaks that develop and leave the dips generally.

Eric


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## nickt

Can you explain "set beginning levels" in #2? Are you trying to get all drivers to put out the same db?


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## ErinH

Eric Stevens said:


> What Erin says in a later post also.
> 
> When you bring both sides together i cut the peaks that develop and leave the dips generally.
> 
> Eric


agreed.

I 'draw' an imaginary line between two points surround a dip and I determine if that area is still high compared to the other side (or high, with respect to the rest of the system response). If so, then I'll do what I can to tame that. If it seems to fall in line, then I just ignore the dip altogether.


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## ErinH

this may help some of you guys when you're analyzing your system response...

remember: reflections are relative to YOU 

If you are sitting 2 feet away from a speaker and then move 10 feet back, the response will change because the reflecting point/angle has changed as well. No one in a car is going from 2 feet to 10 feet, but you can be sure this same principal applies to moving your head even a few inches in a single area. That's why averaging multiple response of an RTA over a 'head area' is so important.


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## sqnut

nickt said:


> Can you explain "set beginning levels" in #2? Are you trying to get all drivers to put out the same db?


What I will do right at the start is to set the tweeters 6db below the mids. Then when tuning for tonality I will play around a bit. Some tweeters will do better at -5db and others will need to be cut a bit more.

Beyond this it's only something I look at after I have balanced L/R, first for each pair of drivers and then with all drivers playing. In most cases with 31 bands per driver and the right timing from drivers, one doesn't need to cut or boost level on a driver on any side.


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## JoshHefnerX

Eric Stevens said:


> You will EQ the right side with the mic in the right seat head location and the left with the mic in the left side seat location.
> Eric Stevens


Hey Eric. If you're making this a 1-seat vehicle. I'm not sure I understand why you would want to mic the left side from the left seat. Wouldn't the sound at the driver seat be more important to eq the environment for that seat?

Josh


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## JoshHefnerX

One other thing when you're removing the peaks that may have appeared when combining the left and right sides. I'm assuming you'd take the same out of both channels - say a 4db peak popped up, you take 2 left and right (or whatever it took to accomplish)

Josh


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## sqnut

JoshHefnerX said:


> One other thing when you're removing the peaks that may have appeared when combining the left and right sides. I'm assuming you'd take the same out of both channels - say a 4db peak popped up, you take 2 left and right (or whatever it took to accomplish)
> 
> Josh


Once you have balanced for L/R and you have a 3 db peak at 1.6khz, you will cut both sides in equal steps till your mic tells you you've cut enough or your ears tell you nah back up, you cut too much. You've got to start off with measuring but you need to eventually learn to do it intuitively and by ear.


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## Eric Stevens

nickt said:


> Can you explain "set beginning levels" in #2? Are you trying to get all drivers to put out the same db?


Yes this means to adjust the output levels so that the relative levels of the speakers are set correctly. Normally this wont mean the same dB level though.

Eric


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## Eric Stevens

JoshHefnerX said:


> Hey Eric. If you're making this a 1-seat vehicle. I'm not sure I understand why you would want to mic the left side from the left seat. Wouldn't the sound at the driver seat be more important to eq the environment for that seat?
> 
> Josh


If you were tuning a single seat system you can do it various ways and the process I desribe will work but you can also EQ separate L/R from the drivers head position. 

A system with a controlled dispersion setup or one with minimal PLD such as HLCD or kick panels you can do a single seat setup based upon the method of EQ left side from the left seat and EQ the right side from the right seat. You just optimize it for the drivers seat. In a car with pillar mounted mid/tweeter with poor PLD you will want to concentrate on tuning only from the listening position.

Eric


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## Souths1der

Eric Stevens said:


> Yes this means to adjust the output levels so that the relative levels of the speakers are set correctly. Normally this wont mean the same dB level though.
> 
> Eric


So, by "relative levels", you mean make sure from the drivers seat (or whatever focal point you're optimizing your system for) all speakers are producing the same db level. So while if you hold an spl meter right next to each speaker they may all read differently, but if you hold it at the drivers headrest they would all read the same.

This is how I would plan to do this, please correct me if I'm wrong. I have my spl meter right by my drivers side headrest. I set my head unit volume up to like 2/3 and play pink noise. I mute all but one speaker and take it's spl reading. Then I mute all but another speaker and take the reading. I proceed like this for all speakers. I would then adjust the levels on each individual speaker so that they all read the same on the spl meter. I would do this by using the lowest output speaker, and let's assume I can't raise it's level and that level is 70. I should then cut the levels on all the other speakers until they read 70. So I would mute all but one speaker and lower the level until the spl meter reads 70, then proceed to do the same to all the other speakers.

For give me because I'm just starting out with tuning, so I'm trying to get a better understanding.  Clear direction and process layout helps me to understand the concepts and so forth. I don't mean to be a nuisance.


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## Eric Stevens

Souths1der said:


> So, by "relative levels", you mean make sure from the drivers seat (or whatever focal point you're optimizing your system for) all speakers are producing the same db level. So while if you hold an spl meter right next to each speaker they may all read differently, but if you hold it at the drivers headrest they would all read the same.


Relative levels means so that it sounds correct, --NOT-- so it measures correctly. Tweeters will typically be at a lower level than the mids, and the subwoofers will be at a higher level than the mids for example.

Most of what I am stating is for tuning a system that will work well for multiple seats while being optimized for the drivers position. If you were tuning a system that was solely for the drivers position forsaking all others you could use pink noise and absolute dB level to match the output levels of left versus right.

Eric


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## JoshHefnerX

I've used your tips for phase and polarity and have achieved a decent strong center. Doesn't waver too much ( I haven't eq'd yet) and is placed pretty high up. But, it's maybe an inch or so to the right of what I'd like to hear. It's not exactly centered under the rearview mirror. So to move that, would you start w/ timing or amplitude?


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## Eric Stevens

JoshHefnerX said:


> I've used your tips for phase and polarity and have achieved a decent strong center. Doesn't waver too much ( I haven't eq'd yet) and is placed pretty high up. But, it's maybe an inch or so to the right of what I'd like to hear. It's not exactly centered under the rearview mirror. So to move that, would you start w/ timing or amplitude?


I think you are saying its to the right of where you feel it should be from the driver seat of a left hand drive car.

With what you describe I would first try amplitude. It possibly could be a peak in the FR from the right side causing what I term frequency steering.

Eric


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## subterFUSE

Sub'd.


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## mmiller

Eric Stevens said:


> I think you are saying its to the right of where you feel it should be from the driver seat of a left hand drive car.
> 
> With what you describe I would first try amplitude. It possibly could be a peak in the FR from the right side causing what I term frequency steering.
> 
> Eric


Can't Phase/polarity also contribute to frequency steering?


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## ErinH

yes.

beam steering. it's how phased array radars work.


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## subterFUSE

mmiller said:


> Can't Phase/polarity also contribute to frequency steering?


Absolutely, because phase can affect how the sounds from different drivers interact and that can affect the freq. response.


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## bbfoto

Thanks for sharing the knowledge. :2thumbsup: Love these threads!


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## mmiller

ErinH said:


> yes.
> 
> beam steering. it's how phased array radars work.


Have you had a chance to play with horns yet Erin? I think remember you expressing interest in trying them out... Unless I'm mistaken.


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## subterFUSE

ErinH said:


> this may help some of you guys when you're analyzing your system response...
> 
> remember: reflections are relative to YOU
> 
> If you are sitting 2 feet away from a speaker and then move 10 feet back, the response will change because the reflecting point/angle has changed as well. No one in a car is going from 2 feet to 10 feet, but you can be sure this same principal applies to moving your head even a few inches in a single area. That's why averaging multiple response of an RTA over a 'head area' is so important.



With this in mind, should we be sitting in the car during measurements and holding the mic next to our heads? Or should the mic just be placed on a stand around the head location, but with no one actually in the car?

Do you prefer mic pointed at the horns, or off-axis 45 degrees, or 90 degrees (upwards)?


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## Kevin K

Well, the way I see it....your in the car while listening....so best to have that same mass in the car while tuning....


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## subterFUSE

Kevin K said:


> Well, the way I see it....your in the car while listening....so best to have that same mass in the car while tuning....


Logically, that makes total sense.

For some reason, I recall having read a contradictory theory on the subject that seemed very compelling... but I can't remember the source. Thus the reason why I'm asking now.


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## Beckerson1

Kevin K said:


> Well, the way I see it....your in the car while listening....so best to have that same mass in the car while tuning....


Actually to add to this if you were to measure without being the car and being in the car this will be evident. 6oud be supprised how much your leg or even foot can effect the FR of a driver.


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## ErinH

subterFUSE said:


> With this in mind, should we be sitting in the car during measurements and holding the mic next to our heads? Or should the mic just be placed on a stand around the head location, but with no one actually in the car?
> 
> Do you prefer mic pointed at the horns, or off-axis 45 degrees, or 90 degrees (upwards)?


I sit in the car with the mic facing up. Just remember: Facing the mic up will cause the HF response to roll off sooner because it's not on-axis with the speakers (the 1/2" electet is like any other speaker; it beams).


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## Eric Stevens

subterFUSE said:


> With this in mind, should we be sitting in the car during measurements and holding the mic next to our heads? Or should the mic just be placed on a stand around the head location, but with no one actually in the car?
> 
> Do you prefer mic pointed at the horns, or off-axis 45 degrees, or 90 degrees (upwards)?



I sit in another seat, so when I am measuring at the drivers position I am in the rear seat or passenger side seat moving the microphone in a figure 8 pattern. I take 10 second averages while doing the figure 8 pattern with the microphone.


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## khaoticle

subbed.


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## subterFUSE

ErinH said:


> I sit in the car with the mic facing up. Just remember: Facing the mic up will cause the HF response to roll off sooner because it's not on-axis with the speakers (the 1/2" electet is like any other speaker; it beams).


I purchased my mic from Cross Spectrum Lab, and they gave me 0, 45 and 90 degree axis calibrations. So I'm guessing with your upward technique you recommend the 90 degree cal file?


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## subterFUSE

Yesterday I began playing with the tune on the horns again.

Set the EQ flat.
Time alignment to zero.
Set LR high-pass @ 800Hz 24dB.
Horns wired in correct polarity, verified by impulse response at close range.


My friend Russ showed me a time alignment by ear trick using a polarity pulse click track. It actually seems to work very well. The clicks are very easy to locate by ear.

Playing just the horns, the clicks were initially pulled way off to the left in front of the driver seat. I then switched over to a "Voice In Phase/Out of Phase" track and confirmed that the horns sounded out of phase.
I changed the phase in the DSP to 180degrees on the left horn, and the clicks snapped closer to the center of the windshield. With a small amount of time delay on the left horn, I had the clicks right in the middle. Checked the voice track again, and it sounded correct. Voice centered when "in phase" and diffuse when "out of phase."


Then I set the phase and TA back to zero, and I just used the time alignment. I delayed the left horn and slowly the click sounds moved from the left to the center. With about .70ms of delay on the left horn, the clicks were just about where I think they should be. Just below the rearview mirror.



So, it seems like there could be a couple of options.

1. Invert one horn, and use minimal time alignment.
2. Leave horns in same polarity and use more delay on the left one.


Advantages/Disadvantages to either method?


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## Eric Stevens

subterFUSE said:


> Yesterday I began playing with the tune on the horns again.
> 
> So, it seems like there could be a couple of options.
> 
> 1. Invert one horn, and use minimal time alignment.
> 2. Leave horns in same polarity and use more delay on the left one.
> 
> 
> Advantages/Disadvantages to either method?


The advantage to flipping polarity is that it will be better from the oposite seat, other than that its the same effect.


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## sqnut

For a one seat car, I would never flip polarity as long as I had TA. Even with something as basic as the p80 where TA is in steps of 0.04ms, one doesn't need to flip polarity. Flipping polarity doesn't cure timing problems as accurately as TA and it messes up the combined response a lot. No matter how good it sounds with flipped polarity, If you have TA you can get it sounding better. With a full blown processor one only loses by flipping polarity. 

When I measured it was always with me in the seat. I would keep the mic near the left ear and take a set of readings looking at the driver side view mirror, another set looking straight ahead, the next set would be while looking at at a point half way to the rear view, then one set looking at the rear view and so on till the far side view mirror. Repeat with mic at right ear. Average for left and right. 99% of the time one is in the car the head is going to move thru this plane. Whats happening above or below this plane doesn't really matter. While balancing for L/R I will keep going back to the measurements while looking straight ahead, cause that's my head position 95% of the time.


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## subterFUSE

Question about crossover points and sound stage height....


When I play my horns by themselves with pink noise, and adjust the crossover point from 800Hz higher... I have been noticing that the stage height moves up as I get to 900Hz and above.

Is this common?

Should I be taking a cue from this and maybe start crossing over a little higher? 

Maybe 900-1000Hz?


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## Mic10is

Do u have mini or full size


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## subterFUSE

Mic10is said:


> Do u have mini or full size


Full Size. Ultra drivers.


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## sqnut

subterFUSE said:


> Question about crossover points and sound stage height....
> 
> 
> When I play my horns by themselves with pink noise, and adjust the crossover point from 800Hz higher... I have been noticing that the stage height moves up as I get to 900Hz and above.
> 
> Is this common?
> 
> Should I be taking a cue from this and maybe start crossing over a little higher?
> 
> Maybe 900-1000Hz?


Height cues are ~1 khz and up. If your horns are mounted higher than the mids then typically lowering the xover point from 1 khz to 800hz should raise the stage height a bit.


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## subwoofery

sqnut said:


> Height cues are ~1 khz and up. If your horns are mounted higher than the mids then typically lowering the xover point from 1 khz to 800hz should raise the stage height a bit.


I don't see this working when horn tuning... Lowering the Xover point most of the time doesn't make your stage higher. 

Kelvin


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## Eric Stevens

subterFUSE said:


> Question about crossover points and sound stage height....
> 
> 
> When I play my horns by themselves with pink noise, and adjust the crossover point from 800Hz higher... I have been noticing that the stage height moves up as I get to 900Hz and above.
> 
> Is this common?
> 
> Should I be taking a cue from this and maybe start crossing over a little higher?
> 
> Maybe 900-1000Hz?


Height of the sound stage is a direct function of how well the system is imaging. The better it images the less localization to the speakers and higher the stage is.

You can learn from this for sure. There are three elements that create the sound stage and images within that stage. Amplitude, Arrival time, and Phase. In different frequency ranges each of these have a varying or different significance / weight in determining the sound stage and image placement. At lower frequency it is Phase dominated, In the midrange it is arrival time dominated, and in the high frequency it is amplitude dominated.

So if you raise the crossover and it images better it indicates the time/phase of the lower ranges of the horns output are not what they should be.


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## Babs

mmiller said:


> Can't Phase/polarity also contribute to frequency steering?





ErinH said:


> yes.
> 
> beam steering. it's how phased array radars work.





subterFUSE said:


> Absolutely, because phase can affect how the sounds from different drivers interact and that can affect the freq. response.


Yep so in car environment, I'd have to guess (keyword, I plan to test) unless the drivers were absolutely perfectly phase/time aligned, if you measure say left mid, then left tweet, get their individual plots, you'd expect and hope the measurement of the two combined would be nicely additive throughout their crossover region.

However, if there is time or phase issue between the two drivers, their combined measurement will not be perfectly additive in the crossover bandwidth, and worst case will have gross cancellations. I guess that's a good clue the two drivers aren't aligned and potentially corrected via T/A adjustment of one or other driver to the other. 

Hence some folks say start with Sub and Mid, align phase and T/A and work your way up.. Then do the other side... Sub/LM/LT, then Sub/RM/RT, then LM/RM, then LT/RT.. for example. I imagine you'd do this AFTER doing an initial best-you-can via the "distance" method to get them close.

... thinking out loud to wrap my head around it.. hopefully. 


Remember seeing one experiment is phase cancellation should be distinct and total (0 db) graphically at their mid crossover point, if you flip phase 180 on one of the drivers.. Prolly far easier to test between sub and mids, vs mids/tweets. I guess the reason I heard some big-time out of phase going on when I played a 2k tone listening to one side when I first fired up the system and did a quick distance T/A setup. Close, but no cigar.


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## subterFUSE

Babs said:


> Yep so in car environment, I'd have to guess (keyword, I plan to test) unless the drivers were absolutely perfectly phase/time aligned, if you measure say left mid, then left tweet, get their individual plots, you'd expect and hope the measurement of the two combined would be nicely additive throughout their crossover region.
> 
> However, if there is time or phase issue between the two drivers, their combined measurement will not be perfectly additive in the crossover bandwidth, and worst case will have gross cancellations. I guess that's a good clue the two drivers aren't aligned and potentially corrected via T/A adjustment of one or other driver to the other.



Yes. If your drivers are out of phase then there would be a dip in their combined response at the crossover region. This is a good final test to verify you have proper phase alignment, after you have done your best by ear. It's really easy to see in REW.


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## Babs

subterFUSE said:


> Yes. If your drivers are out of phase then there would be a dip in their combined response at the crossover region. This is a good final test to verify you have proper phase alignment, after you have done your best by ear. It's really easy to see in REW.


Ah thanks! Yes after posting that, I discovered that very thing myself during EQ'ing the tune I had at the meet better in REW. I discovered a nasty drop-out with mids together. After confirming this with some phase tweaking, I actually pulled out my tape measure and discovered my original distances were off by my error in fact. So I imagine a consistent plot from individual drivers verses being paired together can be a good test for phase coherence.. Don't know if that's an established method or not you pro's use, but appears to be one means by three measurement averages (drivers 1, 2, both). Next for me is figuring out how to use IR curves for T/A.. May need a different non-USB mic for that.

Cross post from another thread:



Babs said:


> I just learned this little lesson. I just THOUGHT my mids were in phase. I noticed playing together they had a nasty dropout at 155hz. Playing with right mid phase at 33-45 degrees I got the blue plot. So back to square one on the measurements and trims. I'm perplexed though because delays are setup by distance measurements.
> 
> I now suspect all drivers. Time and phase alignment are absolutely paramount. Otherwise you're only applying EQ to drivers that aren't playing together at your ears. I've obviously not mastered it.
> 
> Sent from my iPad using Tapatalk


http://www.diymobileaudio.com/forum/2382657-post406.html


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## subterFUSE

Babs said:


> I discovered a nasty drop-out with mids together.


That's exactly what to look for, that dip @ the crossover.

If you have a smooth combined response, try flipping polarity on a pair of drivers and re-measure. You should get a dip like that and you will have visually confirmed you had the correct alignment.




> Next for me is figuring out how to use IR curves for T/A.. May need a different non-USB mic for that.


Correct. In REW you can't do loopback timing reference with a USB mic. Must have a standard mic for that.

In HolmImpulse I believe you can use a USB mic.


----------



## WestCo

*Re: System Tuning Updated 10/8/2014*

Subed


Sent from my iPhone using Tapatalk


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## T3mpest

subterFUSE said:


> That's exactly what to look for, that dip @ the crossover.
> 
> If you have a smooth combined response, try flipping polarity on a pair of drivers and re-measure. You should get a dip like that and you will have visually confirmed you had the correct alignment.
> 
> 
> 
> 
> Correct. In REW you can't do loopback timing reference with a USB mic. Must have a standard mic for that.
> 
> In HolmImpulse I believe you can use a USB mic.


I use that trick a lot myself. Using 24db slopes I'll set my time alignment until things seem to center up. If everything is good, I'll play a test tone right at the crossover point and flip phase to confirm that it gets absolutely terribly out of phase. 

Sometimes I find finding the minimum phase point is easier than finding the maximum phase coherency point, so once i think I have it right, I'll flip phase confirm it gets out of phase. Then with things out of phase, I'll adjust the time alignment again to make sure things get better as I go further away from that point. If I find I can make it worse by adjust the time alignment one click, I'll put it back in phase and listen


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## corcraft

*Re: System Tuning Updated 10/8/2014*



Eric Stevens said:


> The most effective way to do the time alignment by ear I have used is to use one of the tracks on the IASCA CD with a spoke voice and balance or mute so that only the left channel is playing and delay the midbass driver in small increments until the voice is as high as possible. I will then copy this delay setting to the right side midbass driver.


Great read Eric!!! a lot of good pointers! Now when you say copy the delay to the right.... you don't delay the right less because of the distance? 

on another note the car that im working on now I've had to cut the pass side 3-5db to get a centered stage. This is with taking both left and right measurements individualy at the drivers head position. When both sides flat at same level the stage is far right. taking 3-5dB away centers it up. speakers mounted in doors coaxial.... that you may have designed 

which brings me to a third question.... I've always took measurements with me in the driver seat to account for leg position and also to account for reflections with leather interior as it will be when im driving.... Is there a benefit from sitting in passenger seat taking measurements from the driver seat.


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## Eric Stevens

*Re: System Tuning Updated 10/8/2014*



corcraft said:


> Great read Eric!!! a lot of good pointers! Now when you say copy the delay to the right.... you don't delay the right less because of the distance?
> 
> *Eric: Depends if for one or two seats, If for two seats I am using the delay mostly as phase adjustment to get the drivers to play nice through the crossoer region, this improves the stage height greatly *
> 
> 
> on another note the car that im working on now I've had to cut the pass side 3-5db to get a centered stage. This is with taking both left and right measurements individualy at the drivers head position. When both sides flat at same level the stage is far right. taking 3-5dB away centers it up. speakers mounted in doors coaxial.... that you may have designed
> 
> which brings me to a third question.... I've always took measurements with me in the driver seat to account for leg position and also to account for reflections with leather interior as it will be when im driving.... Is there a benefit from sitting in passenger seat taking measurements from the driver seat.


I will usually sit the opposite seat so I can get the microphone in the correct position.


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## corcraft

I did a quick tune today using a lot of your pointers (not all because I don't have an iasca cd) and I must say best tune thus far and took me weeks to get the last 1. I don't know why but I got a lot better results sitting in passenger seat as you said.... I mean the Intial uneqed response was a lot flatter so less eqing even had to be done. 

question: the only frequency that was abnormally different from side to side was 80hz; this is with sub muted. The side that I am tuning (driver) is at least 9db down from the other side and 6db down from flat. I can hold the mic on the other side (passenger) and get the opposite effect so I'm getting either wave cancellation or cabin gain I assume. Would you just decrease the opposite side to match -9db which is -6db from flat? and not try to add any on the drivers side? that's what I did for now and still when I added subs I got a peak at 80hz.


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## Eric Stevens

corcraft said:


> I did a quick tune today using a lot of your pointers (not all because I don't have an iasca cd) and I must say best tune thus far and took me weeks to get the last 1. I don't know why but I got a lot better results sitting in passenger seat as you said.... I mean the Intial uneqed response was a lot flatter so less eqing even had to be done.
> 
> question: the only frequency that was abnormally different from side to side was 80hz; this is with sub muted. The side that I am tuning (driver) is at least 9db down from the other side and 6db down from flat. I can hold the mic on the other side (passenger) and get the opposite effect so I'm getting either wave cancellation or cabin gain I assume. Would you just decrease the opposite side to match -9db which is -6db from flat? and not try to add any on the drivers side? that's what I did for now and still when I added subs I got a peak at 80hz.


I dont worry about separate left and right below 125 to 180 Hz depending on analysis of the whole situation. If I see something drastically off I will take a near field resposne and look for a reason with the system if the difference is there near field.


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## corcraft

*Re: System Tuning Updated 10/8/2014*



Eric Stevens said:


> Signal delay would be the next step to align the midbass to the horns. We want to delay the midbass to align with the horns since the horns are the farthest driver from the listening position. The most effective way to do the time alignment by ear I have used is to use one of the tracks on the IASCA CD with a spoke voice and balance or mute so that only the left channel is playing and delay the midbass driver in small increments until the voice is as high as possible. I will then copy this delay setting to the right side midbass driver.


Having a little trouble with this 1.... I've listened to that voice so long that I think it's a voice in my head now and my mind is playing tricks on me because I keep finding a totally different delay when I go back and listen again. My center image is great! I'm just having a little rainbow I think because I'm having a hard time with aligning the mids. I have "helped the rainbow" but still slightly there and mainly on the right side do I notice it. Have an alterior method that you use? I can't listen to that voice anymore lol.


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## Eric Stevens

*Re: System Tuning Updated 10/8/2014*



corcraft said:


> Having a little trouble with this 1.... I've listened to that voice so long that I think it's a voice in my head now and my mind is playing tricks on me because I keep finding a totally different delay when I go back and listen again. My center image is great! I'm just having a little rainbow I think because I'm having a hard time with aligning the mids. I have "helped the rainbow" but still slightly there and mainly on the right side do I notice it. Have an alterior method that you use? I can't listen to that voice anymore lol.


Depends on single, or two seat, set up.

Couple of notes that might help:
1-For height its more of a phase alignment we are using the delay for.
2- if you havent flattened out the response of the midbass yet you could have some frequency steering.


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## corcraft

*Re: System Tuning Updated 10/8/2014*



Eric Stevens said:


> 1-For height its more of a phase alignment we are using the delay for.


This what I'm having trouble with, I'm not hearing a change in height when balanced to left and adding delay but...... I think I know why now. I'll try it again next week and if it's not what I think then I'll revisit.


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## Eric Stevens

*Re: System Tuning Updated 10/8/2014*



corcraft said:


> This what I'm having trouble with, I'm not hearing a change in height when balanced to left and adding delay but...... I think I know why now. I'll try it again next week and if it's not what I think then I'll revisit.


A early reflection could cause issus as well. Get a large fluffy towel to lay over where a reflection is possible.


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## lup31337

Wrote an article about time alignment using an audison bit ten processor. If you got the proper tools, you can get amazing results. Read about it here.


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## corcraft

*Re: System Tuning Updated 10/8/2014*



Eric Stevens said:


> Depends on single, or two seat, set up.
> 
> Couple of notes that might help:
> 1-For height its more of a phase alignment we are using the delay for.
> 2- if you havent flattened out the response of the midbass yet you could have some frequency steering.


1 Exactly! I tried this ta phase alignment before any eqing. I changed the hp xover to 100 and then to 200 and I was able to make magic happen. Maybe this can help someone that had same issue. If someone was to flip phase of both horns after this I assume would have to realign for the 180 flip?

A couple eq questions and the right answer Is peq and I do plan to put in another processor with peq but in the mean time..... 

2) let's say I have a +15db peak at 1.6khz. Of course when you bring down with a geq it's going to bring down 1.25khz and 2khz significantly when looking at 1/3 octave. Since your not really adding energy to a frequency because it was already there and not boosting above clipping would this be an exception to the no eq boost law? In other words it would be ok to boost those frequencies back up when a peq isn't available correct? Of course I would look at a 1/6 octave to make sure to keep things somewhat flat to make sure not eqing in peaks.

3) continued from above.....let's say that peak is +15db but you only have 12db of cut available. Would there be and issues to cut entire channel 3db then add boost across the board as long as not going over the cut amount? Again with looking at 1/6 octave to make sure no peaks are developing. 

I don't see an issue with either of these methods because not boosting into clipping and not trying to add something that wasn't already there but I've been wrong before.


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## corcraft

*Re: System Tuning Updated 10/8/2014*



Eric Stevens said:


> Depends on single, or two seat, set up.
> 
> Couple of notes that might help:
> 1-For height its more of a phase alignment we are using the delay for.
> 2- if you havent flattened out the response of the midbass yet you could have some frequency steering.


1) Exactly! I tried this ta phase alignment before any eqing. I changed the hp xover to 100 and then to 200 and I was able to make magic happen. Maybe this can help someone that had same issue. If someone was to flip phase of both horns after this would they have to realign for the 180 flip? Or since it is a complete 180 would they still be aligned? 

A couple eq questions and the right answer Is peq and I do plan to put in another processor with peq but in the mean time..... 

2) let's say I have a +15db peak at 1.6khz. Of course when you bring down with a geq it's going to bring down 1.25khz and 2khz significantly when looking at 1/3 octave. Since your not really adding energy to a frequency because it was already there and not boosting above clipping would this be an exception to the no eq boost law? In other words would it be ok to boost those frequencies back up when a peq isn't available? Of course I would look at a 1/6 octave to make sure to keep things somewhat flat to make sure not eqing in peaks.

3) continued from above.....let's say that peak is +15db but you only have 12db of cut available. Would there be any issues to cut entire channel 3db then add boost across the board as long as not going over the cut amount? Again with looking at 1/6 octave to make sure no peaks are developing. 

I don't see an issue with either of these methods because not boosting into clipping and not trying to add something that wasn't already there but I've been wrong before.


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## Eric Stevens

*Re: System Tuning Updated 10/8/2014*



corcraft said:


> 1 Exactly! I tried this ta phase alignment before any eqing. I changed the hp xover to 100 and then to 200 and I was able to make magic happen. Maybe this can help someone that had same issue. If someone was to flip phase of both horns after this I assume would have to realign for the 180 flip?
> 
> A couple eq questions and the right answer Is peq and I do plan to put in another processor with peq but in the mean time.....
> 
> 2) let's say I have a +15db peak at 1.6khz. Of course when you bring down with a geq it's going to bring down 1.25khz and 2khz significantly when looking at 1/3 octave. Since your not really adding energy to a frequency because it was already there and not boosting above clipping would this be an exception to the no eq boost law? In other words it would be ok to boost those frequencies back up when a peq isn't available correct? Of course I would look at a 1/6 octave to make sure to keep things somewhat flat to make sure not eqing in peaks.
> 
> 3) continued from above.....let's say that peak is +15db but you only have 12db of cut available. Would there be and issues to cut entire channel 3db then add boost across the board as long as not going over the cut amount? Again with looking at 1/6 octave to make sure no peaks are developing.
> 
> I don't see an issue with either of these methods because not boosting into clipping and not trying to add something that wasn't already there but I've been wrong before.


You would want to get phase correct first and use the minimal amount of signal delay afterwards. So if you flip the horns after setting your delays you will need to revisit the delay settings as you cant separate time and phase.

I have found if you have 15dB problems showing up on the RTA you should address and fix the problem with other methods first if at all possible.

To answer your question, I will always try and bring the average response level to where it needs to be and then cut any peaks. If when cutting a particular band I affect the surrounding frequencies I will boost them if needed to compensate. 

If there are large dips or holes in the response I will try and figure out why by moving the mic around and looking a nearfield response of the drivers producing that frequency range.


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## dconceal

Where are your horns available at now. I have been out of the loop for about 22 years now. Just installed a system in my 19 year old sons car to keep him from putting in a booming awful sounding system with the help of his teenage friends and he was amazed when I took his civic apart installed the system built him a sealed enclosure for a single 12" and did a amp rack with all the wiring hidden and he still had a trunk! After installing this small system I now have the itch to again compete like the early 90's. I keep reading about your stuff I just cannot find it. Thanks in advance for any information.


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## grinkeeper

great thread


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## corcraft

Eric, phase being the biggest issue with sub imaging. Can you shed any light on your method for aligning? T/A like the mid to horn? If so could you share your method? I have tried a couple different t/a for phase methods but without accurate results.


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## Eric Stevens

corcraft said:


> Eric, phase being the biggest issue with sub imaging. Can you shed any light on your method for aligning? T/A like the mid to horn? If so could you share your method? I have tried a couple different t/a for phase methods but without accurate results.


If you are having difficulty getting it to blend together or localize to the subwoofers you could have another problemratlles or buzzing. It can be vey revealing to run a frequency sweep and listen for rattles and buzzing.

I will always set sub delay / phaser by ear.

One method is: to align using ploarity for best response and then apply delay from there while listening to get the bass as up front as possible. Uusally the amount of signal delay is small, but I have had instances where I just kep adding delay and I could make it better.

Another method: apply delay progressively in small increments until I get the best blend and up front anchor.


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## corcraft

Eric Stevens said:


> If you are having difficulty getting it to blend together or localize to the subwoofers you could have another problemratlles or buzzing. It can be vey revealing to run a frequency sweep and listen for rattles and buzzing.
> 
> I will always set sub delay / phaser by ear.
> 
> One method is: to align using ploarity for best response and then apply delay from there while listening to get the bass as up front as possible. Uusally the amount of signal delay is small, but I have had instances where I just kep adding delay and I could make it better.
> 
> Another method: apply delay progressively in small increments until I get the best blend and up front anchor.



Thanks, I'll go back to 0 and start playing with it a little at a time. My subs blend decently in fact if I hadn't had the ms8 in prior I would be happy. It's when I want the extra impact and turn them up a little that I can localize a ltitle bit which is understandable bc of the notch in fr but..... the 1 thing I liked about the ms8 is that they stayed up front even with the bump on subs so this tells me it is possible. Depending how you measure my subs are either the closest or 2nd closest speaker to me it is 4 subs ib off of 2 channels. 1 thing I thought about but it sounds wrong to me is delay the sub channels separately? In other words ch 1 is closer than left mb. Ch 2 is farther away than left mb. The reason I don't see this as working is bc even though ib its really a trunk baffle and although large they share the same airspace. And 2, stereo is coming out of dsp and amp is converting to a mono signal output to 2 channels (2ch stereo in 2ch mono out) so it seems that would mess with the output signal if it sums the 2 ch together that are delayed differently. Correct me if I'm wrong and I'll try that, or actually if the shared airspace won't cause a problem because so large I could change output to stereo and no other problems exist to t/a (phase) separately.


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## corcraft

Ok, for a 1 seater and t/a. Well, I've delayed the left mid to the highest image with left horn.... I still get some steering so I think my left mid needs to be delayed more in reference to right mid. In other threads I have read that you don't recommend much if any t/a to horns. How do you work around this? Can just delay the mid only but will probably pull it away from horn or delay left horn and mid together? There's probably 15" difference between left mid and right mid.


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## Eric Stevens

After delaying the midbass to get the image as high as possible for both left and right you would delay the left horn and midbass together to get the center where it needs to be. If you still get some steering where its centered over part of the frequency range and not at others you will need to EQ left and right separately and confirm equal amplitude at the listening position once done. 

Another way you could do it would be to mute all but the horns and use delay to focus up the center in the position you want it. Then mute all but the midbass and use delay to get center where you want it. Play all together and delay both left and right mids together to get the Image / stage as high as possible. 

You may need to EQ then go re-do or adjust previous settings and then re check EQ depending on the circunmstances.


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## aroonkl

What House Curve do we use for Horns setup? JBL one?


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## Eric Stevens

JBL is ok but rolls off too much for my taste on the top. I target flat from 250 to 400 and up if using a averaged response over the area of the head when making measurements using pink noise and smooth rising response on the bottom to about +12 to +20 at 20 Hz depending on how it sounds in car. Final is always done listening


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## jim_55379

I am using a TWK 88 and have spent around 60 hours and still cannot get the "perfect sound" I am speaking of "tonal balance" I have tried several RTA programs on my android when I boost or cut 8 DB it doesn't change the RTA values very much. I even tried cutting the entire mid section and it really does not show this in the RTA programs I have used. I even bought a separate microphone (Dayton Audio) that connects to my phone and calibrated it many times. Is there a best program out there. I paid $ 5.00 and purchased "RTA pro" and this one jumps around and the sound on the display is not consistent with the pink noise that is playing. and doesn't seem to help me all that much Thus far I have one or two presets I like somewhat but every time I try (4 hours at a time) the result doesn't sound much better or even worse. I tried "Souind Analyzer" which seemed to work a bit better but sound still has somewhat of a hollow sound to it. I have 6.5 mids front and rear and separate tweeters up front with a subwoofer. Every time I tune it I do it for each speaker watching the RTA screen jump around while I play endless hours of pink noise with my car's cd player. Anyone have similar issues? I think this will drive me crazy listening to pink noise endless hours of adjusting parametric eq and not knowing which way to go. Does one need to purchase those expensive RTA's with complex computer programs? It is already becoming a chore to drag the laptop, charger and phone in the vehicle open the hood and hook to battery charger every time I adjust it and really am not getting anywhere.


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## jtrosky

Do yourself a favor and download and install Room EQ WIzard on your laptop. The phone apps are ok for checking the response of something real quick without much accuracy, but you really need a calibrated microphone (such as a MiniDSP UMIK-1) and the Room EQ Wizard app. When I first got into this, I "resisted" Room EQ Wizard and tried to do it with my phone using the AudioTools app. It'sjust not a good way to tune a car. Room EQ WIzard will make your life _so_ much easier. You do have to spend a little more for the UMIK-1 and some time to learn the Room EQ Wizard basics, but you'll save so much time overall - and end up with a much better tune by using Room EQ Wizard. The app is free.


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## jim_55379

thanks for your reply. Only problem with this is now I will have to purchase another computer or place my desktop computer with monitor inside the car because I also need a laptop to adjust the TwK 88 at the same time or do I just analyze results and adjust eq later? I will have to worry about excessive items (2 laptops and screens) in the car blocking and changing the frequency. I do have a DSpeaker anti mode room correction device with microphone for my home system. It does a series of sweeps to adjust sub frequencies and also does acoustical analysis. If I could figure out how to hook this up and do sweeps it would help also but still would not know which speakers to cut and which frequencies front or rear mids. many things to ponder here I guess


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## jim_55379

Souths1der said:


> I would like to hear more on #1 and if you have some guidelines for starting crossover settings.
> 
> Also, could you expand on your process for #2 on your list?


Great question JL audio recommends -24 db butterworth for all. I currently am using - 12 bw for all except sub . I use - 24db (4 octave) to minimize upper annoying boom and bloat. Still not totally sure but it seems to work ok for me. I use also -12 db for tweeters along with a passive capacitor to protect it so that give another -6db attenuation of the lows


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## jtrosky

You would use the same laptop for Room EQ Wizard and Twk88. I have a Helix and do the same (use Helix app and Room EQ wizard at the same time). You can make both apps visible on the screen at the same time. I'll use the Helix app to mute/unmute speakers while taking measurements with REW.

Although, most of the time, I'll take pink nosie measurements with Room EQ Wizard and then EQ in the house later on my PC with Room EQ Wizard (I have it installed on my laptop and my home PC). I really only sit in the car to take the measurements and brief listening sessions to see how I like the updated tune. I may more some small adjustments while sitting in the car, but I pretty much know what curve sounds good in my car.

I can take a full set of measurements (individual speakers, L+R speaker pairs, left side, right side, subs and finally all together) in about 15 minutes.

Room EQ Wizard can even "auto EQ" the response for you if you'd like.


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## jim_55379

jim_55379 said:


> thanks for your reply. Only problem with this is now I will have to purchase another computer or place my desktop computer with monitor inside the car because I also need a laptop to adjust the TwK 88 at the same time or do I just analyze results and adjust eq later? I will have to worry about excessive items (2 laptops and screens) in the car blocking and changing the frequency. I do have a DSpeaker anti mode room correction device with microphone for my home system. It does a series of sweeps to adjust sub frequencies and also does acoustical analysis. If I could figure out how to hook this up and do sweeps it would help also but still would not know which speakers to cut and which frequencies front or rear mids. many things to ponder here I guess
> 
> I have an older laptop with win XP so far unable to get it to accept the download. It will download but when I install does not work. I will try again tonight but may have to purchase a newer laptop wiht win 10 and also the microphones are out of stock at PP for about one month. there is a place called mini DSP but it is a Chinese company and I am afraid to order because have been ripped off in the past. I did finally get my $ back from credit card company but was a hassle.


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## Eric Stevens

jim_55379 said:


> I am using a TWK 88 and have spent around 60 hours and still cannot get the "perfect sound" I am speaking of "tonal balance" I have tried several RTA programs on my android when I boost or cut 8 DB it doesn't change the RTA values very much. I even tried cutting the entire mid section and it really does not show this in the RTA programs I have used. I even bought a separate microphone (Dayton Audio) that connects to my phone and calibrated it many times. Is there a best program out there. I paid $ 5.00 and purchased "RTA pro" and this one jumps around and the sound on the display is not consistent with the pink noise that is playing. and doesn't seem to help me all that much Thus far I have one or two presets I like somewhat but every time I try (4 hours at a time) the result doesn't sound much better or even worse. I tried "Souind Analyzer" which seemed to work a bit better but sound still has somewhat of a hollow sound to it. I have 6.5 mids front and rear and separate tweeters up front with a subwoofer. Every time I tune it I do it for each speaker watching the RTA screen jump around while I play endless hours of pink noise with my car's cd player. Anyone have similar issues? I think this will drive me crazy listening to pink noise endless hours of adjusting parametric eq and not knowing which way to go. Does one need to purchase those expensive RTA's with complex computer programs? It is already becoming a chore to drag the laptop, charger and phone in the vehicle open the hood and hook to battery charger every time I adjust it and really am not getting anywhere.


The key is in the measurment method, a stationary single microphone doesnt work very well bu tis useful. I do ten second or longer averages set to medium or slow speed and move the mic in a figure 8 where the head would be or a little forward of that in the plane of the tip of the nose. 

If you make an adjustment to a dip in the response and it does not show up on the RTA it means its a null or cancelation and its best to just leave it alone.


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## Eric Stevens

jim_55379 said:


> thanks for your reply. Only problem with this is now I will have to purchase another computer or place my desktop computer with monitor inside the car because I also need a laptop to adjust the TwK 88 at the same time or do I just analyze results and adjust eq later? I will have to worry about excessive items (2 laptops and screens) in the car blocking and changing the frequency. I do have a DSpeaker anti mode room correction device with microphone for my home system. It does a series of sweeps to adjust sub frequencies and also does acoustical analysis. If I could figure out how to hook this up and do sweeps it would help also but still would not know which speakers to cut and which frequencies front or rear mids. many things to ponder here I guess


Measure as i posted previously and then adjust with the system paused.

Stick with 24dB slopes you have less driver interaction and its simpler to get good results.


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## Ge0

jim_55379 said:


> I have an older laptop with win XP so far unable to get it to accept the download. It will download but when I install does not work. I will try again tonight but may have to purchase a newer laptop wiht win 10 and also the microphones are out of stock at PP for about one month. there is a place called mini DSP but it is a Chinese company and I am afraid to order because have been ripped off in the past. I did finally get my $ back from credit card company but was a hassle.


You can buy a fairly nice laptop with Windows 10 for as low as $300. Windows XP was discontinued in 2009. Get with the modern age man .

Also, I'd speculate 60% of the forum members here own some sort of miniDSP product. By far the most popular is the UMIK-1 usb microphone. It would not be popular if it were pure [email protected] 

Just because the [email protected] thing is made in China does not necessarily mean you buy it from China. You can buy one from numerous local sources like Parts Express, Amazon, B&H Photo, Sweetwater, eBay, and even Walmart.


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## Just.call.me.d

Just wanted to give a big thanks to everyone contributing their experience and information on this thread. Being completely new to the tuning (Other than by ear) this has really shed some light on how to tell if your components are in phase and time aligned by using mic measurements and understanding the readings. Good thing I started tuning on my factory speakers instead of the good stuff!
Question, I downloaded some tune files onto a USB stick since my truck doesn't have a CD player, is the IASCA CD/Sound files for tuning available for downloading somewhere to load onto a USB drive for use?


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