ULS-15 phase issue?

[JerryMeeker]

Pete,

Audyssey Pro is issuing a warning message that my sub channel seems to be out of phase. I checked both ULS-15's, and the phase switch is set to zero on both. I have been asked to run the following test:

Take a 1.5V or 9V battery and apply it to the speaker terminals ++ and -- and note which way the speaker woofer cone moves. Industry convention dictates the woofer cones should move outward.


When I run this test on each ULS-15, the speaker cone on one sub moves outward, but the cone on the other sub moves inward. Is it possible that the internal wiring on one sub was inadvertently reversed during manufacturing? If that is possible, then what should I do, simply change the phase switch to 180 degrees for that sub?

Thanks,Jerry

[Pete_Hsu]

Hi Jerry,

There is certainly a possibility that the internal wiring (at either amp end or driver end) was inadvertently reversed. So all you need to do is flip the phase switch on one of the units.

Thanks

Sincerely,

[JerryMeeker]

False alarm. As it turns out, the proper integration between the two ULS-15's and the rest of my system is with the polarity switch on both subs set to 180 degrees. When set this way, Audyssey Pro no longer issues the warning.

[Pete_Hsu]

That's interesting Jerry, looks like like the software indicated that the subs are out of phase with the mains using the 0 degree phase setting, so it is resolved with the phase switch flipped on both units.