Howdy Fellas! I haven't been on in quite some time. I dropped in to ask about my 500. It has a continuous sound emanating from it even when everything is off. I guess the best way to characterize it is very low volume and it sounds like the hum of distant machinery - like something running in your basement. You have to be right in front of it to hear it - or I noticed that you can hear it in the corner. Anyone else encountered this phenomena?

Does the sound go away when you unplug the coax cable and just leave the AC power plugged in? Is it a low rumble bass sound, or more of a hum like a transformer makes?

I think the the humming is possibly pointing to a amplifier that is on its way out. That is one of the first symptoms. I wouldn't leave the sub on standby either until you know for sure what the issue is. It could start making popping noises and then blow (make a big sound) all together which could startle the whole the house especially at night.

Humming can also come from a ground loop which is fixable but they just don't magically appear and the humming is usually present when the HT is on. Ground loops usually come from adding new equipment, cables, room lighting or moving all the equipment to a different part of the house.

My 600 used to make a low rumbling sound that I could hear upstairs, I have to unplug the sub for a few minutes and then it goes away.

The simplest troubleshooting would be to disconnect the sub from your system completely and just have the power cord plugged into the wall and sub with the sub power switch to on/standby. If the hum is still present you need a new amp.

If you haven't already, you could also try removing the grounding screw on the back of the unit.

Ground screw was removed long ago to stop the ground loop hum. The sound does not stop when I unplug the sub cable. The only way to stop it is to turn it off or unplug it. The sound is a lower sound - not like a 60 hz hum. Difficult to describe. It is like the sound of machinery operating far off in a big building. Like background noise. Correct me if I am wrong, but it should be silent when nothing is on? At any rate this is my third amp on the 500.

Hi Argon,

Try re-installing the chassis ground screw which you have removed awhile back. Don't hesitate to dial Axiom's toll free number for assistance. I'll be back on duty tomorrow (Monday) at noon until 8:00 ET.

Hey JC,
I reinstalled the ground screw but it did not stop the hum. I should be free around 4:00 pm ET. I'll call around then.

I recall that you had amp problems in the past, was hoping it was resolved.. Have you tried different outlets, or one on a different circuit just as a test?

It doesn't point to a ground loop like your troubleshooting shows. Unfortunately the fix for this is another amplifier.

Rob, the fact that this noise is present even when the coaxial cable to the sub isn't connected and the only connection is the power cord, shows that this isn't a ground loop noise, since there's no connection to form a loop. Apparently there's a problem in the power supply section of the sub amp and either the rectifier or a filter capacitor is going bad.

Randy,
I will try another outlet, the way the room is wired, however, they will all be on the same circuit. Other than this issue, the sub is performing admirably. I was concerned that it could escalate - that is the reason for the post. My wife went to visit our daughter the other night and I rented Battle Los Angeles. Watched it loud and there is plenty of LFE.....

[/quote]It doesn't point to a ground loop like your troubleshooting shows. Unfortunately the fix for this is another amplifier. [/quote]

We'll see. I plan to call and talk with JC tomorrow.

Yeah, I never thought it was a ground loop but I went through the checks just to eliminate. Just another item to vie for my attention.

Just to bring closure....JC is making it right. Should have a new amp sometime in the next couple of days.

So wrapping up the thread title: "You Love Axiom Long Time?"

That was flagrantly tacky, I know.

I'm Fergie Ferg and me love you long time.

Well.....not quite wrapped up yet. I just got the replacement amp.....good. THIS version does not have an RCA input on the back....bad. It does have the XLR 1/4 input.......good. Axiom did not send the male adapter I need to connect to the new amp.....bad. So...just got off the phone with Axiom and they are going to send the adapter. Being that this is my 4th amp for the 500 and knowing that Axiom will make it right - I still feel like.....

There must be some US Customs delay in crossing the border? When I get the ship notification from Axiom, It always state the tracking number will become active midnight the following day. I got notification on Wednesday that the adapter has shipped but I couldn't track until last night and it says delivery next Tuesday. Not complaining - just musing.

tracking for US customers activates once the product has entered the US and is in the FedEx US system.

ok.....maybe this is the last post. The adapter was scheduled to be delivered today. I get home and ask my wife if I have a package. She says "not that I know of". I check the tracking page. It says "Delivered to the front door - no signature required". I run to the front door....nothing. I run to the garage door......nothing. I call the closest neighbor.....nothing at either of their doors. I e-mail Noreen lamenting my problem. On a whim I call the neighbor way up the street....voice mail. I go about my business....an hour later neighbor way up the street calls back.....bingo. I drive up get the package and head back. Second, never mind e-mail to Noreen. It's all good....

sounds like a busy day, hope things are working out for you, it has been a long road for you and subs.