I have read threads about ground loop issues, etc. However, this doesn't happen when I have a sub in the mix of things. Currently, I just have the M80's, and a VP 150 hooked up to my HK AVR, and when there is nothing playing, there is a high pitched hum coming from the speakers. Anyone know what I might try? Maybe removing the banana plugs (from Axiom) might help -- i.e. just going to bare wire?

Any other suggestions would be highly appreciated. Thanks in advance.

Mids and tweeters? Or tweeters only?

A poor speaker connection wouldn't reveal itself as a high-pitched hum, so I highly doubt the banana plugs are to blame. What I'd do in this case is disconnect components from your amp/receiver one at a time (turning off the amp/receiver first, of course) until you find the one that is causing the hum.

But before you even do that, I should ask if the hum is audible at all volume levels and with each input selected.

I agree. Change inputs ( DVD to CD or TV ) with nothing playing to see if the hum continues.

Will try...once I get home. Thanks for the responses...but I am not sure which of the three it's coming from. I will unplug the center, and see if the fronts are humming, and vice versa (ie take out the center, and keep the fronts).

See ya...on my way home now...

I really don't think that it is your banana plugs. Try what the other have posted and I think that you will find that it was some sort of ground loop. They can be quite tricky.

Still haven't tried any 'tests' on the system. Wednesday evening was quite tough, since I had to move stuff out of the old place, before the closing on Thursday. Then, Thursday took most of my day, while attempting to store all the empty boxes that we seem to have collected, during our move. Also closed on the old place yesterday, which took most of my day...whatta nightmare.

I did manage to wire everything up, and all the speakers are now wired...but I have not had a chance to do much testing with the components that are hooked up. I still have yet to mount the surrounds.

Once I have the system calibrated, and the 4 QS8's mounted, I will test the connections that are going to/from the receiver. Needless to say, it's been a really hectic couple of days. Basically, I am just glad that we closed on the old place, and are basically all moved into the new place. Talk about a relief!!!

Anyway, more to follow.

So, I unplugged everything from the receiver. Now, all that is plugged in, is the speakers. The hum is still there.

Could it be the surge protector causing this?

Volume levels don't seem to matter, as in, no matter how high or low the volume, I can hear the high pitched hum. Maybe I should try and unplug things from the surge protector? That might/might not help, but that might help? I will try, and report back.

Did you try changing inputs even with nothing connected. Or maybe try changing from dolby to dts to see if it makes a difference. Try to see if in input is bad.

Also try connecting directly to the wall outlet.

Good idea with the surge protector. Try plugging the receiver directly into the wall. Also unplug other devices that may be on the same circuit.

I think I may have figured out what the issue is -- when I turn the 'Tone In' = 'ON' I hear the hum, on different surround modes (though not all), at most volume levels (HK Receiver basically goes from -80 to +10) so the louder it goes, the worse the hum.

For $HIT$ and giggles, I turned the 'Tone Out' = 'ON' which got rid of the hum, except at really insane levels (i.e. -10 to +10) on the receiver. I also tried different surround modes, here...and had the same effect. No hum. I also tried different surround modes, and did not expperience the hum, below a certain volume, with the Tone Out = ON.

So, I am thinking that it was the 'Tone In' settings, where I had the treble up and the bass low. Don't know why I would be hearing a hum, though? I will try taking the unit out of the protector, and plugging it directly into the wall...and try both tone in and out modes tomorrow (later this morning, when I wake up again)

I will also be contacting HK customer support, and/or Onecall's customer support. Let's see what they have to say. I also sent Brent (at Axiom) an email, and maybe he will shed some light on this issue, as well.

More to follow...when I am able to do some more testing. G'nite.

Now I know this will spark a discussion here....
But...a line conditioner or a good surge strip is sure to atleast help you trouble shoot the issue. There may be something running in that new house of yours that may be giving you the hummmmm.