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· Registered
894 Posts
Discussion Starter · #1 ·
I got done setting up and dialing in my 5.1 system...and once in a while...I would start to hear the subwoofer hum. Talk about annoying.

I started by checking to make sure the cables were firmly attached to the AVR and the subwoofer. Ok..better.

Few days pass...it came back. This time I switched from LFE on subwoofer to Speaker in. Woot! Few days later back again.

Darn Monster Subwoofer cable I knew 12 bucks on ebay was too good a deal. I think I have a generic one someplace ...

3 hours later (and a few choice words) found the sucker downstairs. Ok...good deal...stupid Monster ...fixed.

A week later..back again. That's it... I am calling Rythmik..I know they have good Customer support. One of the reasons I bought my sub.

As I am muttering to myself and red in the face I get the bright idea...I should at least do a google search and see if it is something I can fix.

Sure enough ...took me to a thread from this very forum... It said number one cause of Subwoofer hum was a non-grounded cable coax..

Well...my AV powerstrip did have a coax in / out just never used it. I did the test they recommended...humm with cable plugged in..no hum when I disconnect.

2 min later...no subwoofer hum for last 3 weeks.

I know that there were a few threads on this in the forums but thought I would add to them as this really saved me... Hope it helps someone else.

· Registered
58 Posts
In case anybody else is looking here for hum troubleshooting here's what I found:


The driver (not amp) on my F15 hummed whenever I plugged a computer on AC power into my receiver (HDMI or analog stereo). If the laptop was not plugged into the AC adapter it did not hum. Also happened with a desktop computer.


a) Plug the computer in on a different circuit


b) Use a 3-prong to 2-prong plug adapter to plug the F15 into the outlet.
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