time delay correctly applied, finally

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=90788
Printed Date: May 12, 2025 at 2:00 PM

Topic: time delay correctly applied, finally

Posted By: haemphyst
Subject: time delay correctly applied, finally
Date Posted: February 21, 2007 at 10:27 PM

Hi kids! Well, I finally got off my duff, and sat down to apply some TD to my system, and I must say, it sounds as good (in the driver's seat, anyway) as my system in my house. Below is the screenshot af the applied TDs. I know it looks a bit weird, but the outputs are 1, 3, and 5 to the driver door, and 2, 4, and 6 to the passenger door. Output 2 is the furthest driver from me, so all the others are delayed to match IT'S arrival time. Output 5 is the driver's tweeter, and the closest, so it has the longest delay, as you can see.

posted_image

Can you say IMAGING!?! Heads up, in the extreme. Bob, I'll have to drive this thing over there soon... You won't believe it!

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Replies:

Posted By: DYohn
Date Posted: February 21, 2007 at 11:27 PM

Cool deal Dave. Time domain issues are far more critical than distortion or maybe even FR in generating a proper sound field. Congrats.

I assume this is the software control for one of your Alto devices?

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Posted By: aznboi3644
Date Posted: February 21, 2007 at 11:30 PM

lol I have no idea what this means

Posted By: stevdart
Date Posted: February 22, 2007 at 6:38 AM

I use the ol' standby solution to time domain issues...do a gangsta lean on the center armrest. lol

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

Posted By: haemphyst
Date Posted: February 22, 2007 at 8:33 AM

1: If the image above doesn't look nice, or is not easy to read, here's a link to see it bigger, in a new window.

2: Yes, that's the Alto piece. I always KNEW it was a nice, powerful piece of gear, but GEEZ... when I went poking around in there, I found things I had no IDEA it would do! Now, when I get the OTHER one in place for the SUB! WOOHOO! Yeah, it'll sound good... And I still haven't even touched on the EQ capabilities yet! Because I chose very nice drivers for the doors, I probably wont need much EQing if any at all, but the other one will be all EQ duties, most likely... gonna BFI those woofers into a flat curve! We all know the car is a TERRIBLE place to try to get flat bass... posted_image

3: azn, the ideal speaker array is one that is a point source, producing ALL frequencies from the same point. Difficult if not impossible to do ANYWHERE, let alone in a car, the next best source is a vertical line - a "line source", also difficult if not impossible to implement in a car. What the time delay does then, is acoustically "moves" the drivers away from my ears, so that all of the sounds being produced arrive at my ears at the same time. The drivers, while not being moved physically, are receiving a slightly delayed signal to play, so my brain "thinks" they are all exactly the same distance away from my ears. This electrically produces a "line source" in my doors. The passengers woofer, it is the furthest driver away from me, so it needs no delay, and that can be the reference sound source. The passengers midrange is about 3.5 inches closer (than the woofer) to my ear, so it received enough delay to make it about 150mm "further away" from my ear than it actually is. The passengers tweeter is about 5 inches closer to my ear (than the woofer), so it received enough delay to make it 193mm "further away"... And so on. Is that a little better? If you need more, just ask, we'll be happy to explain.

4: "Gangsta lean". Funny stuff! I used to do that too, but my doctor said it was bad for my back! posted_image

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Posted By: Sad, little man
Date Posted: February 22, 2007 at 9:08 AM

After using time delay, I wouldn't buy a head unit that didn't at least let you adjust the basic four channels. I just wish I had control of my door tweets separate from my woofers. Looks good. (But what is this the control panel from... And where can I get one? posted_image

)

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'96 Mazda Miata

Posted By: haemphyst
Date Posted: February 22, 2007 at 10:26 AM

The time delay in a deck (as you have discovered) will only allow TD to an entire CORNER, it can't be used to individually TD each driver in an array, you need a device like I am using for that. It happens to be the Alto USC-Pro (you'll actually have to click on that item in the list... I hate frames...) The control panel you are seeing is from the software installed on the PC which is used to set and control the unit. I will tell you, in your present setup, you will not be able to use ANY external signal processors, as you only have 2 channels of amplification. My system, for example, right now has 6, with 2 more to come for the subs.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Posted By: Sad, little man
Date Posted: February 22, 2007 at 11:43 AM

Yeah, I know I'd need to separately amplify all my speakers to do that, it's just a cool little device that's right up my alley. Still, four channel time delay sure beats none at all. Really turns the music from background noise to something that actually has a presence. Neat how it even takes the temperature into account when doing the delays. Now, what would be really trick is if it had an ambient temp sensor on the unit that adjusted the time delays according to the temperature in the car. posted_image

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'96 Mazda Miata

Posted By: aznboi3644
Date Posted: February 22, 2007 at 6:05 PM

Ahh I see what you are talking about now...pretty nifty

My friend has an Alpine deck with a Time Alignment thing and wants me to set it for him, it is exactly like what you are describing but only controls 4 channles...but I have no clue how lol

Posted By: Sad, little man
Date Posted: February 22, 2007 at 8:32 PM

Page 17 in this manual has a good explanation. Basically you want the speaker furthest from you sitting in the driver's seat to have no delay, and then every speaker closer to have a delay set so that the sound coming from them gets to you at the same time as that farthest speaker. It has calculations too for milliseconds.

">&Container=com.webridge.entity.Entity[OID[218A80359A29924B952108F2E6318D6C">">&Component=com.webridge.entity.Entity[OID[8322E7CCE8CF514284908057180D9DA1">">">My Alpine Manual

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'96 Mazda Miata

Posted By: Steven Kephart
Date Posted: February 22, 2007 at 8:55 PM

Glad to hear things are working out well for you Dave.

I do have a question though, where did you get that processor? I can't find any dealers for them anywhere. I figure if I ever want to update my head unit, I will need a good processor as I won't be able to use the Sony unit anymore. And I wanted one that had at least close to the same precision. These things seem to be rather scarce now, unless you go with say a pro sound unit like the Behringer, but then you have to tweak the power supply for 12 volts.

BTW, if you ever want to compare the two, here's the software for the old Sony unit: https://www.matronics.com/XDP-4000X/dsc.zip

Posted By: Steven Kephart
Date Posted: February 22, 2007 at 9:00 PM

DYohn] wrote:

p>Cool deal Dave. Time domain issues are far more critical than distortion or maybe even FR in generating a proper sound field.

You peaked my interest with this comment. I remember Dan Wiggins once telling me that a flat frequency response is 90% of a good imaging soundstage. I always thought that the time domain was one of the least important as our ears are only sensitive to it on a limited bandwidth (except for maybe the effects it has in the frequency domain). This topic interests me and I'd love to hear your point of view.

Posted By: DYohn
Date Posted: February 23, 2007 at 11:36 AM

Actually I should have used "sound STAGE" rather than sound field. Time alignment is critical to creating a proper soundstage, since the relative times the different frequency bands reach our ears is how we determine things like location, depth, size, position... all the psychoacoustic effects so well described by so many people. Reverb, delay, reflections... all that. Dan is right (as usual) that FR is 90% of how we qualify sounds, but TD effects can create havoc with the FR of a system in a listening space. It is probably more critical to control reflections and have proper time alignment in a system in larger spaces like a room than in a car, but time alignment errors and reflected sounds can cause lobing, phase shifts, etc. with the attendant nulls and peaks that can make a well-designed system sound like trash. These effects then become more important than distortion or FR to the sound the listener perceives. posted_image

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Posted By: master5
Date Posted: February 23, 2007 at 1:37 PM

Correct me if I'm wrong but I always thought time delay in a vehicle to correct for listener off axis positioning would work...but only for the position it is set for.

In other words..if set for the drivers position assuming that you occasionally have a passenger(s)..or an SQ judge, wouldn't the delay effect hurt those listening positions even more? Unless of course you don't care about the imaging/staging for anyone else but yourself..lol

But anyhow I am impressed with what is being attempted. Good job and thanks for sharing the knowledge.

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Posted By: haemphyst
Date Posted: February 23, 2007 at 2:11 PM

master5 wrote:

Correct me if I'm wrong but I always thought time delay in a vehicle to correct for listener off axis positioning would work...but only for the position it is set for.

No, that is absolutely correct.

master5 wrote:

In other words..if set for the drivers position assuming that you occasionally have a passenger(s)..or an SQ judge, wouldn't the delay effect hurt those listening positions even more? Unless of course you don't care about the imaging/staging for anyone else but yourself..lol

Again, absolutely correct, and... "wull, yeah..." posted_image

master5 wrote:

But anyhow I am impressed with what is being attempted. Good job and thanks for sharing the knowledge.

Thanks and if you have any other questions, ask away!

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Posted By: master5
Date Posted: February 23, 2007 at 3:49 PM

Yeah..wouldn't it be better to "simply" place the drivers seat to the center of the interior???

Oh wait..thats been done...kidding aside thanks again for sharing all the "rocket science."

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