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Discussion Starter · #1 ·
When I used the auto time alignment on my Pioneer DEH-8650, the sound feels hollow or poor in bass. The distances calculated are
  • driver side front speakers is 220cm
  • passenger side front speakers is 280cm
  • driver side rear speakers is 250cm
  • passenger side rear speakers is 340+cm
  • subwoofer is 400cm

However, when I switch off time alignment or I use the headunit's factory settings for time alignment, the sound feels solid and bassy although there's some alignment issues.

Anybody knows the reason for this?

My setup:

My car is a compact MPV.
Headunit - Pioneer DEH-8650
Front Speakers - Rainbow Audio DL-C6.2 components running passive with tweeters on A-pillar pointing to the middle of the cabin at face level.
Rear Speakers - Rainbow Audio KX165 coaxials at rear doors.
Amp - Soundstream Rub4.600
Subwoofer - Mac Audio 10" in a sealed enclosure in car's rear boot facing upwards. Powered by an Alpine class D amp.
 

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Check the polarity at all the speakers, and be prepared to lower your expectations a bit. Autotune can be OK, but it's seldom great.
 

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Just measure the actual distances and enter those. You may find that better than auto TA.
 

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Discussion Starter · #5 ·
Just measure the actual distances and enter those. You may find that better than auto TA.
Initially, I did that, but the sound stage was messed up real bad.

I am going to check the polarities of the speakers and will update this thread.
 

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Discussion Starter · #6 ·
UPDATE:

I found that one of my rear speakers was connected in reverse polarity. I tested it by switching off the front speakers and the subwoofers, and then i used the fader/balance to shift the 'focus' point from left to right and back. When the focus point was at the center of the rear seats, the sound didn't sound 'synchronised'.

So i switched the polarity of one of them and tested used the auto T/A and the settings for the rear speakers went to 300mm and 400mm for left and right rear.

Front Left - 220mm ...... Front Right - 160mm
Rear Left - 300mm ...... Rear Right - 400mm
Subwoofer - 260mm (Crossed at 50Hz. -12 levels. Normal)

So I switched both of them, and the current settings are as follow...

Front Left - 220mm ...... Front Right - 160mm
Rear Left - 160mm ...... Rear Right - 220mm
Subwoofer - 400mm (Crossed at 50Hz. -15 levels. Reversed)

Any advise on whether this is correct? How about the subwoofer? Should I switch the polarity, or just toggle it in the headunit?
 

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I'd try one of the "setting TA by Ear" methods that are on here. I'd have to confess I never tried that with front and back component sets...
I think you would get a "stage" in your head like headphones :eek:
 

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Fade all the way to the front (forget the rears for a bit) and measure distance to your front mid bass and the sub. Enter these and listen to it. You have a 13 band eq, that should help in dialing in nice tonality.
 

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You could also try switching polarity between every mid and tweeter...

Listen to each channel with the rest muted with tweets "in and out" polarity... When it sounds like the sound comes out of the spot between the drivers then it is mostly ok.. When you hear both drivers from their own location it's mostly not ok...
 

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Discussion Starter · #14 ·
I'd try one of the "setting TA by Ear" methods that are on here. I'd have to confess I never tried that with front and back component sets...
I think you would get a "stage" in your head like headphones :eek:
i tried to use the Autosound 2000 CDs...and I couldn't get a better settings than auto TA. maybe it was due to the speaker being reversed? i'll try it out soon.
 

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Discussion Starter · #15 ·
"Friends don't let friends have real fill" So, drop the rear fill man. :)

On a serious note, the following thread is quite a good read and worth your time to attempt. This technique really helped me get my sub to appear up front, but i know others who have found the entire process most beneficial.

http://www.diymobileaudio.com/forum...5069-better-technique-ear-time-alignment.html
I am driving this type of car...http://4.bp.blogspot.com/_Zc20646FF78/SopXyLhTwoI/AAAAAAAAAWY/V7a15Te9h0w/s400/toyota-wish-white-front.jpg. Without rear fills, the sound feels too distant to my rear passengers.
 

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So you are trying to T/A a set of passives up front with the tweet mounted up high and mid in the door? That is prob your problem there.
Not really. Our ears cant pick phase differences in the frequency range that most tweeters play. ~2khz and up, the ears are sensitive to amplitude difference and less sensitive to arrival time differences.

As long as the OP has his MB and MR close to each other he can TA based on the mid bass as suggested.
 

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Discussion Starter · #20 ·
UPDATE #2:

So I reversed the polarity of the subwoofer wiring, and the current Auto TA settings are as follow...

Front Left - 220mm ...... Front Right - 152.5mm
Rear Left - 180mm ...... Rear Right - 260mm
Subwoofer - 262.5mm (Crossed at 50Hz. -13 levels. Normal)

Previously, it was...

Front Left - 220mm ...... Front Right - 160mm
Rear Left - 160mm ...... Rear Right - 220mm
Subwoofer - 400mm (Crossed at 50Hz. -15 levels. Reversed)
 
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