My EP500 is 2-3 months old. My EP500 sometimes makes a slight hissing sound when my system is off. This is not a hum but a noise that sounds like when you put your ear to a sea shell. It does not change when I move the volume control or switch the subsonic filter or phase switch. It goes away when I turn the crossover knob all the way down to 40 HZ and get progressively louder as crossover knob is turned up toward 150 HZ. This sound is not comming from my system as it remains when I pull off the sub cable. If I switch off the power and then turn it back on the sound goes away and the sub remains quiet until some time later.

Has anyone else experienced this and if so what was the resolution?

hmmmm... try calling axiom. Maybe need a new amp?

Hmmmm Steve,

Interesting...do you have to get real close to the sub to hear it, or can it be heard from the seating area? I used to have a similar problem when I had my subs plugged into a different outlet in the room on a different circuit from my other stuff. I think I could even hear the sound coming from the other speakers.

As soon as I plugged the sub into a different outlet on the same HT circuit it went away. Does your 500 have a ground screw on the back amp plate, if so you could try removing that and see if that helps, but that is normally for ground hummm.

The only other option would be to call the Axiom tech 800 line, Brent, JC, and the others answer that until the evening hours...

Wierd problem and it is intermittent. It is not a ground loop since it still occurs when the sub is not connected to the system. You should call 1-866-244-8796 and talk to the customer support staff or one of the engineers to see what they have to say about this issue. I suspect there might be problem with the amp. Keep us posted.

Try opening it up and letting the snake out.

That's what she said.

Good one, Charles.

Steve, as others have pointed out, if the problem exists with no connection to other equipment, a ground loop can't develop and the problem appears to be internal to the sub. Contact Axiom directly since a defect in the sub amplifier may have developed and it needs to be replaced.

Update: Talked to Brent at Axiom and he also thought amp was the issue and is sending me a new one. Thanks everyone for feedback. I will keep you posted on fix.

Received and installed new amp today. So far so good. I will reserve judgement for awhile as problem with old amp was intermittent.

Good luck Steve, let the Rumbling begin..

Sirquack we are quick on the draw tonight aren't we?

Good news rvrrat. Hopefully it didn't take a lot of effort and time to swap out the amp.

Great news. I hope it settles your problem.

I love how they package the replacement amps they send you. VERY well packed!

Yes, I'll bet those re-uauable shipping caskets would have some stories to tell if they could only talk.

You mean your's didn't talk? Mine sure did! As soon as I saw it, it said, "OPEN ME"!!!!

Mine said "I hope you have a very strong drill sucka!"

That's half the reason I want a replacement amp--I wanna see that shipping container!

My amp came double-boxed. The outer box was brown sacrificial cardboard. The inner box was very solid and had a stately black appearance. It came with a free driver attached to the front. The only problem was that it had a large rectangular hole punched into it just below the driver.

But the rectangular hole was free?

When they sent me my amp I looked out on my porch one day and there was a box sitting there that said, "EP350" on the side. I thought, did they accidentally send me an EP350? Or is the amplifier for the EP800 as big as an EP350?

Either way, the answer to my question was.... SWEET!!!