subwoofer T/A VS. phase

[tcguy85 10+ year member]

should t/a have an affect on phase, specifically on a sub?

i was playing around with both the phase and t/a on my sub tonight, just trying different things out.

i had the sub set at 38" away and the phase on "normal"... set the sub at 160" instead (where the auto t/a puts it) and it sounded kinda strange... reversed the phase and SHAZZAM, sounds better than ever.

this leads me to believe that different t/a setting may cause the need to change the phase. is this obvious and i didn't realize it? am i crazy? //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

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[thch 10+ year member]

sounds about right.

as for the Q, well, a wave goes through 360d per cycle, and each cycle has some period, eg 20hz repeats 20 times per second, so 50ms per cycle. so every 50ms, 360d of the wave play. thats around 7d per millisecond.

and for 100hz, there is 360d per 10ms. so 1ms of delay is 36d of phase shift

looking at a few more points, its easy to see that a time delay means phase increases linearly with frequency.

this is not bad, as the group delay -- the difference in time arrival -- is zero.