Page 1 of Subwoofer hum

I have a Warfedale M5.

My B&W Powerbass active subwoofer is connected to the speaker outputs of my Prologic amp (haven`t moved onto DTS/DD yet). My M5 is connected via analog channels to the amp. No problems with that.

But the M5 also has a dedicated subwoofer output which I`d like to use instead. When I connect that directly to the subwoofer, I get a hum comming out from the sub while a disk is loading (I don`t get it while the disc is loading, only after it`s loaded). The hum doesn`t go unless I turn its power down, which is no good because the sub isn`t giving any effect with low power! When I disconnect the M5 feed from the sub, the hum goes away.

Does anyone else get this problem, or know how I can combat it?

Thanks,

Sarmad.
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This item was edited on Sunday, 16th December 2001, 02:03

Hello.. I have a Wharfdale Topaz Active Sub.. This Hum`s abit when I connect it to the Sub Out on my Amp... It might have something to do with with the Transformer which powers the Box. I could do with some ideas aswell.... Cheers.

Anybody else - dont mean to hijack the thread but I have the same problem. Pioneer W-S80 active sub that hums quite loudly whn switched on - just set the system up on saturday after much excited unwrapping but the hum is really putting me off. I have tried different leads but without any success.

Have tried all the settings on the amp before realising I get the same effect when its switched off as well. If anyone has any ideas I`d also be most grateful.

I used to have this problem with leads longer than .75m. so it restricted were i could place the sub. I finally solved it though by spending a little bit extra and buying really good quality cable, and moving the power leads away from the audio leads so they can`t pick up on the field generated by the mains lead. Now my sub hides behind the sofa on the end of a 4m. cable
hope this helps
regards kevin

Cheers Kevin

I`ve tried different leads and different lengths and the hum is the same. It hums as soon as the power is turned on, even when the line input is disconnected. I have also tried isolating the power lead away from any possible source but without any effect.