TIME ALIGN

[rich carnese]

Does anyone know how to calculate the amount of delay needed to time-align components? I would imagine we're converting inches to milliseconds!
I think Its an oft overlooked area that reaps significant aural benefit. Also...can the delay be accomplished by passive means? Thanks.

[toddalin]

Does anyone know how to calculate the amount of delay needed to time-align components? I would imagine we're converting inches to milliseconds!
I think Its an oft overlooked area that reaps significant aural benefit. Also...can the delay be accomplished by passive means? Thanks.

Speed of sound at sea level is about 1,116 feet per second, so it works out to be about 1.1 ft per millisecond. Most people just use 1 foot/ms.

Sure, just move one speaker forward or backwards accordingly.

[Zilch]

13.56 in/ms

[boputnam]

I think Its an oft overlooked area that reaps significant aural benefit.

Also...can the delay be accomplished by passive means? Thanks.

Not that I know of.

...just move one speaker forward or backwards accordingly.

But be mindful that passive crossovers induce measurable "delay" between drivers - this particularly impacts the woofer (IIRC, this is imparted by the inductor in the HPF, but my knowledge of crossover design is admittedly limited. I'm a user... . Someone no doubt will correct me.)

[edgewound]

Does anyone know how to calculate the amount of delay needed to time-align components? I would imagine we're converting inches to milliseconds!
I think Its an oft overlooked area that reaps significant aural benefit. Also...can the delay be accomplished by passive means? Thanks.

Yes it can be done passively. P.A.S. has done it extensively with Time Offset Correction*, and so did UREI with Time-Align* monitors.

It has to do with calculating the crossover filters' phase delay of physically offset voicecoils.

You won't find the formulas to calculate such passive filter wizardry here but you might find it in a copy of LEAP or some other filter design software.

[UreiCollector]

Also...can the delay be accomplished by passive means? Thanks.

All passive crossover exhibit a phase shift along with affecting amplitude. The trick would be to use that phase shift to "align" the drivers. As to how to make this happen, I don't know....Urei used a crossover designed by E.M.Long to time align the 604.

I have seen the use of so-called "all pass" crossovers (active analog) that exhibit time delay (through pase shifting i believe)....but, this obviously doesn't meet your passive requirement.

[boputnam]

The trick would be to use that phase shift to "align" the drivers. As to how to make this happen, I don't know....

Yea, exactly my quandary...

[moldyoldy]

Divide the wavelength at XO by the percent of phase shift where 360 degrees = 100%

(Or should I say multiply...? You get the picture.)

Handy-dandy wavelength calculator;

http://www.mcsquared.com/wavelength.htm

[moldyoldy]

Example;
With 90 degrees shift (25% of 360) at 800Hz (16.95")
16.95" x 0.25 = 4.2375" offset

[boputnam]

Example;
With 90 degrees shift (25% of 360) at 800Hz (16.95")
16.95" x 0.25 = 4.2375" offset

Yea, but to know what is going on, he'd need to measure the speaker output, and iterate the design.

[SEAWOLF97]

..can the delay be accomplished by passive means? Thanks.

YES , Lincoln Walsh designed it into his full range driver. Works very well , thank you.