Loud humming noise from subwoofer (by 6 users)

I work for Cerwin Vega and normally when this happens is ground looping problems, for the solution we would suggest our customers to purchase an adapter from a three prong to a two prong.

I had same problem caused by a poorly grounded cable TV line. Try disconnecting the coax cable (the one which comes in from outside) from the back of your cable TV converter box. If the problem goes away, you probably have poorly grounded cable TV service. A $50 ground isolater filter will fix this (see model Model VRD-1FF at: http://www.jensen-transformers.com/iso_v...

I installed one recently and it works as promised... No degradation to digital cable/data service and the annoying hum is gone.

Hopefully your cables aren't damaged, because they're attached to the unit and very difficult to replace. I just had this same problem, and after reading the first suggestion checked my cables for damage and found nothing. However, a closer look at the back of my computer showed that the audio cable running between my sound card and my amp was only halfway in. After correcting the problem, the feedback disappeared. Good luck.

I had the same problem with the relevant subwoofer. The problem could simply be about the placement of the rest of the speakers connected to your amplifier. You have to be able to place your fronts and rears in a position that doesn't cause any coincidence. The best placement for a 5.1 system is that fronts are towards you with the subwoofer in between, or next to the front-left, and the rears are just next to your seat. If you use a 2.1 (stereo with a subwoofer), it needs some fine-tuning on the subwoofer and the amplifier as well. I hardly stopped that irritating noise. Firstly, I set the frequency of the subwoofer to 100Hz; then turned the volume down to the quarter level. After all those, I turned up my amplifier's "subwoofer volume leveler" to maximum. I solved the problem. try it out..

if it is a powered sub you should lift the ground. you can do this by adding a three prong to two prong adapter. you know, like when you go to plug something in and the cord your plugging in has three prongs and the outlet your plugging in to only has two. it doesn't have the hole for the ground so you go get a little grey adapter that has three holes on one side and two prongs or tabs on the other.if that doesn't take the hum out (actually, is keeping the hum from getting in) you have a problem with the amplifier.

Hopfully you fixed your problem by now but just in case, in addition to what dannydan suggested you may also want to make sure you don't have a ground loop from the ac supply line(120VAC), try relocating the plug to a sepearte outlet on a seperate circuit if possible, or ensure your input cables are not runing next to some ac lines. The hum is usally caused by the EMI (Electromagnet Interference) from your ac lines. this is the 60 cycle hum we get from the 120 Volts 60 Hz lines.

It also depends on where you have placed the base unit - if it is too close to the amplifier or other electrical devices, this will cause humming. Try moving it atleast a couple of feet away from any electrical devices.