Time alignment peeps

Anyone here delved in the realm of T/A? I know at least of one other user here, Babs, that uses t/a.

I am happy/content with my pioneer 80prs serving the duties for t/a, and in the future, looking to install horns, and a standalone dsp unit.

I got fountek 89ex 3.5" widebanders for mids, b&c 8ndl51's for midbass duties, and (2) sundown audio sd3 12's for subs, being powered by jl xd600/6, and zed minotaur respectively. so far, this is fulfilling my needs, until I get some horn bodies and a dsp.

my purpose, to play loud and crisp at highway speeds, and thus far, I am right there.


anyway, anyone else out there with a system that is time aligned?

 

With my setup, and speaker locations, the stage is coming out of the center dash. Much better than the sounds being localized to each speaker location. If I move my head to the center of the cab, I can definitely "hear" the stage being split evenly. worlds apart from not being time aligned.

 

It's primarily all of the in-cabin reflections that causes imaging to shift when your head is moved (not to mention you also modified the path length differences between the speakers). Hard surfaces (dash, windows, etc.) all contribute to it. I really only listen to my car stereo when I'm driving, so I settled on having the best experience while in the driving position. I get a slight "rainbow effect" while driving, but centered vocals are pretty while anchored in the middle of my front bumper.

A correlated pink noise track is the best time alignment tool I've used thus far. There's a good tutorial on diymobileaudio.com that goes through the process of using a correlated pink noise track and adjusting time alignment while listening for the doppler effect. I'd say it gets me about 90% there, then critical listening on some well known tracks and final minor tweaks will get me to where I want to be. I'm continually playing with time alignment and crossover point and slope to get rid of the rainbow effect, but I've come to realize there are physical restrictions (speaker size/type and location) that are holding me back. Other financial priorities are preventing me from addressing those issues at the moment.

 

Im also on diyma, and have tried numerous methods on t/a. for me, it was just using music, and adjusting by feel. I think my system is pretty dialed in for the little amount of effort and money I have spent on it. I believe I am at a crossroads of diminishing returns, if I want to through moe money at it, but a helix dsp and some horn bodies do sound tempting. maybe in a year's time.

 

Those B&C woofers definitely have the efficiency to keep up with horns.

Are you using the 80PRS crossover for your widebanders or the amplifier crossover? I wish the 80PRS would allow adjusting the HP crossover below 1.25kHz.

Also, how do you like those SD12s? I have an SI bm MKIV that sounds very good and blends well with the midbass, but I'm still wanting a little more output. I'm thinking about trying to find a second MKIV used or going a different route all together.

 

I use the correlated pink noise technique ike mentioned and if you learn how to use the separate left/right equalizer on the 80PRS you may be surprised at how your stage/imaging can be improved even with only 13 bands. (rear fill done properly can also enhance your front stage)

 

It really is amazing how much improvement you can get with just 13 bands. Someone on DIYMA posted mono pink noise tracks bandpass filtered and centered around the frequencies provided on the 80PRS. I use these tracks to adjust corresponding left and right EQ bands until each one is centered and all the tracks as a whole sound like one vertical column in the middle of my truck's hood. This technique has yielded great results.

 

I had my 80prs crossing the mids and widebanders at 1250hz in network mode, but just recently switched to standard mode, so I could use my xd600/6's crossovers at 500hz just to try it out. had to re configure the eq(which I am still continuously doing), and I feel it was a little better thus far in network mode, probably do to more tuning time.

how do you adjust the eq bands for left and the ride sides?

edit: figured out how to do left and right eq adjustments

 

after a coupla days of adjusting the independent bands of eq, I think I pretty much have the image centered just above my dash. I imagine a thin fog hovering the dash, and that is where the sound is coming from.

not bad for using quality components in stock locations

edit: in other news, it sounds not so good anywhere else in the truck, outside the driver's seat

 

That's awesome. Are you still using your amp's crossover or did you switch back to network mode? I'm very curious about trying some widebanders.

 

I am using the amp's crossover for the 500hz point for the low pass for mids and high pass for the widebanders. Otherwise, the 80prs takes care of everything else