I am sure you can find member or 2 of this board who are willing to give you a hand with this.

 

Have you tried to flatten the FR of the left and right side independently first? Doing this seemed to help and show the best results for me.

Sent from my SAMSUNG GALAXY NOTE using Tapatalk 2

 

I know what you mean about it being tricky to center the image by ear. Here are a few thoughts:

Bass freq are localized by phase relationships, meaning small variations in level won't change where the sound seems to be coming from, so matching levels at lower freq isn't as important. Obviously large variations in level are noticeable though (more then 3db).

Midrange freq, the bulk of most sound, everything is important - both level and phase. Sounds above 1Khz are mostly localized by level, so matching spl is very important.

With that in mind, as a test, take one of your door/kick woofers and reverse the phase of just one side (negative wire to positive post, positive wire to negative post) and listen. You'll probably find that many midrange, midbass sounds seem to be more infocus and more centered than before. This is the sound you are aiming for when you play with your EQ. Assuming you are tuning the vehicle to sound best from the drivers seat, you will probably have most freqs above 1khz set to be louder on the passenger side than the driver side. Since the passenger side is farther away from you, it will need to be louder to compensate for the distance.

In my car, I have the driver's door woofer out of phase, passenger door wired normally and both tweeters are in phase. This gives me a stronger center image in the car.

If you want to use measurements to assist you, above 1khz you want your db's to match as closely as possible between your left channel and right channel when measured from the drivers position. Since you will probably never choose the EXACT (down to the millimeter in all directions) same spot to measure from every time, take a few measurements from each freq and average them.

Midrange freq are the trickiest to get right since they are affected by everything in your install (body panels, locations, distance, resonances, db level, etc). Here is where reversing the phase might help you. Also, try not to raise any dips in the freq response beyond 3db or you risk damaging your speakers. Concentrate on lowering peaks in this freq range.

As always, your experiences will vary based on your install, speaker locations, etc., but hopefully this will help you get started.

 

I can try to help. I'm assuming, however, that you have TruRTA (since you mentioned it "not being helpful")....it should be helpful. I'm also assuming you have determined your speakers are in phase and you have appropraitely set your crossovers as needed. I'll assume last that you have access to pink noise on a cd (correlated versus non-correlated....i don't feel like getting into that argument, but I mostly use mono (correlated) pink noise. If this isn't the case, I've made an "Ass" out of "U" and "Me" As mentioned try to cut as much as you can...boost at a minimum.

1. if you can't mute your speakers independantly or don't have independant speaker EQ control, go to step 2 below. Flatten the left side independant from the right using your TruRTA. After flattening the left side, pay attention to the db level (or overall line) that you have just achieved (you can probably even get a number). it may not be perfectly flat, but it will end up being around a certain db. Then go and try to replicate this on the right channel (replicate = make it flat as possible overall and as close as possible to the same db level or line). On my AC RTA machine I just make sure the line created by the led lights ends up on the same line as the other channel. if you have speaker level volume control, that will make it easier to get flat.

2. if you don't have time allignment, move on to #3. if you have Time allignment, input your measurements. Some argue this is to be input later, but this is when i do it. I have my reasons

3. Turn on all speakers together and take notice of the RTA line. If you EQ'ed independantly, jointly boost/remove frequencies at both left and right so that you obtain the curve you want. if you are only able to EQ all speakers at once with one 31 band EQ, this is where you need to start and get everything flat or boosted and cut into the specific curve you want. A popular curve on here through Andy at JBL is: 20-60 +9, smooth transition back to zero at 160, flat to 3k, smooth role off up to -3 from 3- 22k.

4. Listen by ear to tests tracks and then actual music you are very very familiar with. This is where i am looking for help from others.....ie specific songs for specific frequencies for specific reasons. One song I know quite well is U2's with or without you. The bass guitar at the beginning is very pronounced and the 4 chords are like (73, 55, 65, 50) give or take a few db either way. I mostly just listen that the bass guitar is smooth from one chord to the next. Again that is just one small example. I wish i could get via this forum a whole list of songs like this. In fact, you have inspired me to start a new thread

 

If you are seriously into car audio SQ, you should make the next trip to the SoCal GtG. It's located in Anaheim, not far from L.A.
It's a nice gathering for bunch of car audio enthusiatic to come together and listen to each other car audio and learn.
Here is the link for the last meet. They haven't announce the next meet, but I am sure it will be soon.
http://www.diymobileaudio.com/forum...om/forum/12-volt-events-team-diyma/128177-so-california-meet-june-9-2012-a.html

 

People have warned "you can't measure it...you must use your ears"; I'll tend to agree right now, as neither a PAA3 nor a PC-based TruRTA set up seem to help.

I don't agree. It's very easy to measure it and very very doable. I can sit for hours and try to tune a independant L-R 31b GEQ, when listening fatigue kicks in (sooner or later it will when listening to noise) you can't trust your ears very much. Easiest way imo to tune fully by ear is to play sine tones at every frequency band 50-63-80-100Hz etc... and center each frequency. This effect will increase above 500-600Hz and level matching will determine your entire center image beyond 1,5kHz.

My recommendation is to use aRTA or RoomEQ (both free) to measure your listening position, average 3-6 points around your head. Use RTA function with infinite averaging in RoomEQ to measure 200Hz and down. After 300-400 points of averaging RTA you'll have a good measurement.
Above 200Hz I run MLS/sweep 64-128k length.

After you done measuring, set T/A. Phase errors between elements will present themself will major dips in frequency response. Midrange/tweeter phase errors will be clearly audible when playing music, stage will be messed up if phase setting is incorrect.

I use 12db/12dB 63Hz lowpass/highpass between subs-mids. Measurements tells me that this setting allows for the flattest response, and also sounds best in my car (tried 40-50-63-80Hz, from 6-36dB and compared FR). When I T/A I reverse the phase on purpose, adjust sub T/A until you have a non-existant bass response and then turn phase back to normal and you'll have a perfect sub-midbass integration. After T/A and phase are correct, fine adjust FR 1dB +/- by listening to good recordings with nice center image. You should be able to hear the slight difference in staging and centering.

Here's how it looks (RoomEQ) just before tuning (inital measure):

All measurements:

Subs, Mids FR L-R:

 

Hmmm, where to start. Yes, duckymsce, I attended the SoCal MECA event this weekend, and scored miserably. I believe my system sounds a lot better today, as I learned at the event what to listen for.

Next disclosure is that my system suffers from two shortcomings which won’t change in the near future:

1) I’m using passive crossovers,
2) I’m using factory speaker locations…I’m believe the tweeters aren’t so well positioned, because I can hear wavering/pulsating sound patterns as I move my head to various positions when playing tones above 1Khz…I assume this is from less than perfect speaker alignment (i.e., they’re pointing too much at each other, and at varying listening positions the sound actually cancels itself out…changing time alignment doesn’t eliminate the wave irregularities…just moves them around).

Using TrueRTA, I played with the 31-band graphic equalizer settings as well as the Auto Tune function for hours…always hampered by the wavering/pulsating sounds which I assume are caused by improper speaker.

I concluded today that my system, which suffers from the two drawbacks noted above, is best tuned using the Pioneer DEX-P99RS’s Auto Tune function, with select manual fine tuning applied afterwards using the 31-band graphic equalizer and the help of TrueRTA.

To me, it seems that the DEX-P99RS uses a parametric equalizer in the Auto Tune process…this may be a significant factor with respect to tuning my system, as I’m using passive crossovers and can’t independently control tweeter and mid-woofer volume using channel-specific gain controls. I simply could not replicate the Auto Tune curve using only the 31-band graphic equalizer. I’m assuming the DEX-P99RS’s Auto Tune function is applying a wide band parametric equalization which adjusts frequencies in a much different manner than the user-controlled 31-band graphic equalizer. I’d love to hear a Pioneer technician confirm my observation regarding the parametric equalization in the Auto Tune function. Now, if I wasn't tied to passive crossovers and had an additional amplifier, I surely would unlock an added level of performance from the DEX-P99RS.

I’m also hoping someone can confirm that the wavering/pulsating high frequency sounds I encountered were indeed caused by improper speaker alignment. If it weren’t for this wavering, I could easily have set up the system using TrueRTA…so, yes Hanatsu, I agree, if it weren’t for the high frequency wavering/pulsating (unique to my system), the set up process could very much be completed simply by playing tones and measuring db levels.

 

I assume you don't run the passives bi amped? Then you'll have no T/A between tweet-mids. Check the phase between these, often you need to invert phase it the speakers are far from eachother. Remember that a complete phase inversion at 3000Hz (assume crossovers are set around here...) only translates to 4.52/2 = 2,26 inch in physical wavelength.

 

Could be wrong since I've never used the P99RS but I really don't think the auto-tune uses a PEQ while the end users only have GEQ adjustments - doesn't seem logical to me.
If the firmware can do PEQ, I'm pretty sure they would let the end user use PEQ too...

My opinion,
Kelvin

 

I own the P99RS, I assure you that it does use the built in 31b GEQ, auto function have no additional benefit other than it's easy to use.

In other words, you can make any setting by your own that the autoEQ performs. Too bad you can't actually see what it does. However you can see what autoT-A calculates, in my system both autoEQ and T/A was pretty bad, autoTA doesn't seem to work with 3-way fronts. AutoEQ boosted the crap out of my mids, but sounded ok in midrange. Center image was slightly off. Don't like the auto function really, however it might work as a guideline for futher tuning...

 

Well, I’m glad I waited to reply to this thread. I withdraw my statement about the DEX-P99RS using a parametric equalizer not manually accessible to the user.

After days of experimenting with all manner of test tones and pink noise, I could never improve on the Auto Tune. Attempts at manual tuning didn’t even come close to the Auto Tune. Then, I wiped away a bunch of saved setting and started tuning from scratch manually…ostensibly a last attempt. Everything suddenly clicked into place.

Funny how easy it is once you get the hang of it again. I say “again” because I tuned my original head unit installation…an Alpine 9813 way back in 2003. The DEX-P99RS is a new addition as I decided to keep my current vehicle a few more years…I simply forgot what to listen for and I think was thrown by the 31-bands of equalization.

So, Hanatsu…you are indeed correct that manual equalization with the DEX-P99RS can match that of the Auto Tune function (I believe I’ve greatly surpassed it). And yes, I’m running passive crossovers (fancy old school stuff) between my tweeters and mid-bass, and I don’t feel the need for active crossovers there…the system sounds truly amazing.

And Libertyguy20, while your suggestion didn’t drive me to do it, you’re right about listening to familiar tracks…I’ll add to that the realization that really pulled me over the hump and that’s as follows: once you lay down your initial EQ settings using real time analysis, then use the equalizer to work on eliminating the sound you don’t need…do this while listening to familiar music and carve away the unfamiliar noise…start with a clear female vocal and get her properly sculpted and balanced, that’s when everything clicked for me...I worked my way up and down the frequency spectrum from there and in just a few minutes all the pieces fit together like a jigsaw puzzle.