Starterwiz

Not only does a proper time alignment give good stage, it can also increase the "apparent" SPL.

My first encounter with it was a few years back, using a Planet Audio Bethoven amp. It had a dial to adjust the phase.

I finished the install, tweeked everything else,cause I thought there would be very minute diferences to listen for when dialing the phase.

Well HOLY!!!! when I got to the sweet spot on that dial, it was amazing. Everything got sharper, tighter, the toms, and snare drums just smacked.

Nice to have a dial to be able to instantly hear the difference. Much harder to "remeber"howit sounded just before punching a pile of buttons on a deck. Of course the digital delays in the decks offer far greater flexibilty, but not better ease of set-up for a novice ear.
One of my installers has a DEH-P960MP, and it never sounds awesome to me when I get in his car.

Now if I had it to play with for a week or two, I bet I'd get it dialed in, but not so easy to do in a quick tune-up.

GrizZz

Well in my defense, I never bought this head unit, so no, no-one has explained it to me. I bought it's predecessor, the KDC-X969. The 969 was an awesome HU, I loved it, it just turned out to be a lemon... Kenwood finally replaced my lemon 969 just a month ago, two years after I bought it, with a KDC-X979. The 979 has a few more features than my 969 did, like time alignment & 5.1 Dolby Prologic II.

Anyway, the 969 impressed the heck out of me on how good it sounded... and this 979 sounds so much MORE better, it gives me wood!

The downside, Kenwood makes lousy owner's manuals... In the manual, it just shows you HOW to set the DTA and cabin size, not what it actually does or in any detail at all. Which is why I've asked...

I just wanted to get an idea of what's going on, set things close to what they theoretically "should" be, and THEN tweak by ear from there...

It doesn't let me adjust left/right DTA other than with the "Position" setting I wrote about above, although I can adjust each speaker's volume individually as well as globaly. And the DTA for the front, rear, centre, and sub channels shows feet, no milliseconds. And using the preset "Van, long" just set the fronts at 1 foot and the rear and sub at 0, which just makes no sense in my head. They should be as one of you said I thought, the fronts about 2.5 feet, rears about 10 feet, sub about 6 or 7 feet, since that is about how far each is from my head when I sit in the driver's seat.

Lappy, you say your sub is set at 0 because it's the furthest away... that still makes no sense to me, shouldn't it be about 6 feet away, since it IS actually about 6 feet away from your head? Or are you basing your measurements from the sub, like your rears are a foot or two away from 0 (your sub) and your fronts are 8, 9, 10 feet away from your sub? So should I base my measurements from my head, or from my sub?

Thanks to all!

[ March 31, 2005, 08:16 PM: Message edited by: GrizZz ]

lappy

The measurements have to be taken from your head.

The goal with Time Alignment, is that the sound from each speakers arrive at your listening position at the same time.

To do so, you will need to delay all speakers of your set-up except the furthest one that should be set at 0 because it's the one who's sound will arrive the last at your listening position (So, no need to apply a delay on that one).

If you have let's say, 4 speakers plus a sub to set, you will need to measure the distance between each speakers and your listening position and apply (by measurments) the appropriate delay (and output level).

Here is the mathematical formula (from my Eclipse manual) to do it:

A = (B-C) / 34

A is the delay time (in microsecond)

B is the distance from listening position to furthest speaker

C Distance from listening position to the speaker to be adjusted

Example : If your sub is your furthest speaker, you calculate the distance from the sub to your listening position and keep this measurment.

Then you choose the speaker that you want to adjust the delay (let's say the front right), you measure the distance from your listening position to the front right speaker and keep the measurment.

Now, you simply make a substraction and a division.

Example : Sub distance from listening position is 200 cm, front right speaker distance from the listening position is 50 cm. you have a number of 150 cm. You divide this number by 34 and the result is your delay setting (in that case, 4.4 microsecond)

200 cm - 50 cm = 150 cm / 34 = 4.4 microsecond

You apply the 4.4 microsecond to the right speaker and leave the sub at 0.

So now, in theory, the sound of your sub and your right front speaker, should arrive at your listening position at the same time.

You simply need to do the same operation for all your speakers and your set!

Sorry for the long and explanatory post but english is my second language and it's not always easy to explain what I want like I would want.

Anyway, hope this solve your mystery.

Good night.

Steve


Steve

mugen1

^^ if all time alignment adjustments were done the same from one manufacturer to the next. I think his is front only, not front/left and front/right.

That leads me to believe it uses a different method. But then again, I don't have a Kenwwod, either.

BTW, GrizZz, did you try what I suggested? I just want to know if my guess was anywhere close to being right.

GrizZz

Ya I haven't gone as far as breaking out a tape measure, but I did punch in the approximate distance from my head to the speakers.

I then stuck on some light techno, with crispy repetitive highs... and could hear the time difference in the front & rears, tweaked until they sounded better, and it's mucho better, I thinks.

Thanks guyz!