604E voice-coil displacement

[selmerdave]

Wondering if anyone can tell me the amount of displacement between the LF and HF voice-coils. I'm going to try an active setup and mess with time-delay on the LF, there is a description of a process to test in the manual but I wouldn't mind knowing what the distance is to make sure what I end up with is more or less in agreement. Many thanks.

Dave

[bfish]

Hi, Dave,

I don't have one to measure, but it's easy enough to do. Simply measure the axial distance from the center of the front plate of the large mag to the center of the rear plate of the small one. This will be approximately the same as the depth of the entire mag structure less 1/4", which I'm guessing will be about 6-7", which equals about 1/2 millisecond of delay. That's a very fine adjustment on most XOs.

You'll get far more accurate results (if you have the test gear) by adjusting for peak combined (measured) output while playing a sine wave at the XO frequency. If indoors, check it with the mic or spl meter on-axis at different distances to make sure you're not getting any reflection error.

[klausesser]

Hello Dave!

It?s 5,375inches which means 215degree at 1500Hz.

best, Klaus

[selmerdave]

Many thanks guys, I'll report back on my results.

Dave

[donaldpatten]

Dave
My 605A's measure 408 usec; 604E's will be more.
Try listening to drum tracks.I use some old Motown cuts ;The Temptations ,Commodores,The Pips, Steve Wonder, ... try to get a CD Best Of MOTOWN 72-92.
Don

[donaldpatten]

Dave
The CDs are VOL I & II:
Hitsville USA.: [sound recording (CD)] the Motown singles collection, 1972-1992.
Don