Time alignment questions for your JLU

[Malcris]

Hello All,
I'm running a fairly aggressive audio setup in my JLU with Audio Frog GB60/GB15s in the dash and GS20's in the Soundbar. 2 Jl subs forward firing in a tailgate enclosure. I'm running my signal path through a helix DSP.3 but I'm having one heck of a time trying to get the sound dialed in, especially the time alignment.

Current settings are as follows:
Front High's X-Over 3100 HP 24db/slope
Front Mid's X-Over 2800 LB 24 db/slope
Sound Bar X-Over 110 HP 24db/slope
Subs X-over 72 LP 24db/slope

(all butterworth alignment)

The problem I'm having is the Helix wants the front left mid as the reference speaker for T/A (Usually the closest to the driver's listening position) but in the JL the Soundbar speaker is much closer to the listener than the front left. Whenever I try to use the Auto Time alignment feature it gives me wacky results.

I've tried the measurement method using a tape but that yeilds terrible results as well.

So far My best sound setup has the Sound bar with 6.0ms of delay, the sub at 6.43ms, front left mid at 0, front left high at .67ms, front right high 1.87 (5.562 degrees off phase) and 0ms for the front right mid.

Even with this setup I still cannot get the sound stage centered in the jeep.

Couple of things....Power is not my issue and all of my amps are in phase (Jl audio HD's)
Front Tweets are installed in factory location, front mids the same (Modified Metra enclosures).
Sound bar has been fully sound deadened
Entire tub of vehicle has been sound deadened and heat treated
Soft Top installed.

Any thoughts/help is appreciated, I've heard of a JL tuning system that's proprietary to the VX amps that will supposedly yield a good setup because its mic's use 24 listening points inside the vehicle. Unfortunately, I don't have $100K to drop on that system to tune my car....LOL.

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[lashlee]

What mic are you using with the Helix software? The MTK-1 or UMIK?

I would look more at the amplitude difference from side to side instead of tackling the time alignment. I don't have my laptop with me or I could look to see what I set the T/A on the last JL build I did. If you've read some of the posts from Andy, he sets T/A with a measuring tape and never messes with modifying it since it matters very little as long as you're close. I would guess that you've got the drivers out of equal amplitude thus making one side seemingly louder/out of whack. When I start tuning, I set the T/A with a tape, then work on setting levels of each driver to a given driver (I typically use one of the midranges to compare to). I would start there, then mess with EQ once you've got levels set.

 

[Malcris]

Good thought. but my amp gains are exact and output is equal too. The issue is the soundbar and it’s closer proximity to the listener than the fronts. I use the MMUK from Dayton, it a pretty good cheap alternative to the AC mic

 

[lashlee]

That's where the problem lies. Once you've got the gains set on the amp, use the output levels of the DSP to limit the output of the speakers so that arrive at the mic at the same amplitude. Since the soundbar is closer, those will have to be reduced the most.

 

[Malcris]

Yes, I did that and still no luck. To your point I’m going to bridge one of my HD amps (I’ve got 2 free channels originally reserved for a center which I didn’t install)to send 300 rms to the GB60’s, let’s see if that works. I’ll keep you posted.

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