Time alignment?

[Moses Magnum]

HI,
I'm hoping someone can take a look at this mdat file and let me know if I need to time align the subs.
Thanks in advance

 

[sm52]

Time alignment required. Try like this. L shift by 3.9ms, L sub by 1.5ms, R by 2.6ms.

 

[Moses Magnum]

Thanks, so I've got this right.
Left speaker delay by 3.9ms and the delay left sub by 1.5ms?
I could be completely wrong here, but shouldn't I only delay either the sub or the speaker? I have 2 subs currently running in stereo, not mono. Please feel free to virtually slap me if I'm typing rubbish.

Right speaker delay by 2.6ms compared to the right sub?
Thank you

 

[sm52]

The right sub remains in place. For the rest of the participants, delays are applied as written. L 3.9 ms, L sub 1.5 ms, R 2.6 ms.
Try it. If you don't like it, you can cancel everything.

 

[BenToronto]

As some others have noted here and there, time alignment is one of those concepts that sound important but may not be that beneficial to sound quality.

 

[Tim Dawson]

As some others have noted here and there, time alignment is one of those concepts that sound important but may not be that beneficial to sound quality.

Depends on the space. In larger rooms with larger delays, the differences can be huge!

 

[BenToronto]

Depends on the space. In larger rooms with larger delays, the differences can be huge!

True. But best not to confuse long-distance judgments (like reinforcement speakers at the back of a large church matching the slow arrival of direct sound from the front) with domestic HiFi.

My most relevant test is with a Klipschorn bass which added 12-18 feet to the path of my ESL panels, XO about 130 Hz. The benefit even on a sparse few test pieces was tiny.

Proper system design starts with prioritizing audible shortcomings, no fixing stuff that ain't broke.

 

[Tim Dawson]

I'm talking about the physics, not the application. Many high end vendors over the years have tooted thier horns about using driver setback to align tweeter/mod/woofer on speakers (so, either marketing nonsense, or they think it is important . . . I always favored nonsense, overall, but did experience a case when tuning active crossovers in a monitor, where a touch of delay really helped smooth out the high crossover point . . .) . . . . The impact may be small, but it the concept is very very real . . .

 

[Moses Magnum]

Thanks for the help and input folks.

I'll have a fiddle tomorrow, I was just a little confused as to why delay both left speaker and left sub. My limited understanding thought using the left speaker as timing ref for left sub would mean adjusting just the left sub.

Well, every day is a learning day.

 

[Tim Dawson]

Thanks for the help and input folks.

I'll have a fiddle tomorrow, I was just a little confused as to why delay both left speaker and left sub. My limited understanding thought using the left speaker as timing ref for left sub would mean adjusting just the left sub.

Well, every day is a learning day.

Basically, furthest away from you (latest arrival) becomes the reference, and all others delay to match. If subs are equidistant from the listenjng position, then could be the same, if not . . . (and this also presents the issue of a large listening space, where distances vary drastically, so aligning for one area may be detrimental to another. Lots of things to consider in this case . . .

 

[JStewart]

As some others have noted here and there, time alignment is one of those concepts that sound important but may not be that beneficial to sound quality.

I find some confusion with the use of the term “time alignment” when referring subwoofers and mains, when phase alignment between the subs and mains to maintain a smooth frequency response over the transition frequency range is what’s really desirable.

My limited understanding thought using the left speaker as timing ref for left sub would mean adjusting just the left sub.

And to add to what @Tim Dawson just said, the timing reference is used to maintain the relative timing among a group of measurements. There may be others I’m unaware of, but one reason for needing it is the computer system latency may not remain constant. If it did, REW would be able to calculate based on when it starts the signal or the like.

 

[sm52]

I was just a little confused as to why delay both left speaker and left sub.

For the place where the microphone was located, the right sub turned out to be the latest. You cannot make a negative delay. Therefore, the rest of the participants are delayed to align with the right sub. And there is another reason why to delay the left sub. So that the right and left sides, together with the subs, work in harmony in time.