I recently got the Epic Master package, but the subwoofer has a hum coming from what appears to be the built-in amplifier. As soon as I turn the power switch on, a fairly low level audible hum begins. I can hear it easily from about 6ft away. I have tried plugging the sub in a different AC outlet in another room (with nothing else connected), and I get the same hum. Anyone have ideas as to what could cause this? Or how I can alleviate this?

I would try just a couple of things before we proceed to investigating your amplifier. Just plugging the sub-woofer into the wall without an input source will normally cause the sub-woofer to hum. I would try putting a speaker wire into the high level input and see if it hums. The normal cause of humming is the RCA connector so this eliminates that possibility. If it still hums then I would contact Joe Vassallo at either joe@axiomaudio.com or 866-294-6688 and he will make sure to get it all working perfect for you.

MikeyB,

I have also heard that hum you are talking about. I noticed it is loudest when the sub is in the Auto Off mode. Ian, I highly doubt it is due to the RCA connector I have. I have a very high quality cable, and it does this hum if my received is off, and if there is neither Line Level nor High Level plugged into it. The hum, however, seems to disappear when there is a signal going into it, or when it is not in Auto Off mode. I read a review of the EP125 (the sub I have) in an online magazine once, and they said they also heard the same hum.

Ian,

Thanks for the response. When you say "try putting a speaker wire into the high level input", do you mean connect the subwoofer in my system this way, or just hang a single wire off one of the terminals with the other end not connected to anything?

Hi Mikeyb,

Ian means that you should connect the speaker cables from your receiver or amp to the high-level inputs on the sub and make sure the cables are connected to your receiver or amp as well. Don't connect the RCA low-level input at the same time as the high-level inputs. Turn on your amp or receiver and see if the hum goes away.

You either have an AC ground loop, likely caused by your cable-TV or satellite connection (if you have either) or traceable to other components connected to your receiver, or there's a defect in the amp in the subwoofer.

Try the remedy above first, then disconnect your cable-TV connection from your TV, if that is part of your A/V system. See if the hum goes away. Let me know the results of these tests first, then we'll take it from there.

Regards,