Testing for Time Alignment, time offset, or time delay

[donaldpatten]

Comments please

Has anyone tried to measure or verify the offset time on a high frequency horn and a woofer either with a passive or active crossover? To adjust the delay on A7 style speakers, simply slide the horn fore/aft in the cabinet. On 604s it must be done electronically.

To try measuring the timing you need a microphone, mic preamp, and an O’scope

The test signal is FREE and here on the web .


www.donpatten.com

The test signal is after the two schematics and can be played on your PC. Just click on the playback small triangle, in the short box, to start playing the tone. Connect the PC headphones output jack to the amplifier input.
Connect the mic to the preamp and the preamp to the scope input.
Connect the External SYNC / Trigger connection or the second channel input to the amplifier.
Play the test signal with only the woofer connected, and stabilize the scope trace.
Now turn the horn on and off checking for side-to-side jumps in the trace.
Now adjust the horn position or XO time delay to eliminate the side-to-side jumps.

When the trace is stable, check the large pulse, with the horn on; it should get taller and narrower when the timing is correct.

If you have tried this, or any other technique please comment , and share your knowledge.


Don