Any idea why an ep600 would randomly start making a thump thump noise when all sources are turned off to it but power is still turned on to it's amp? Really annoying at 3AM. It functions normally otherwise.

I has something really odd with my SVS that happened years ago.

Randomly, and after months of not having any issues, it would randomly go into what I am calling "full power, deep bass" mode. Completely random and freaked us out even when it was during the day. I even would unplug the source cable, and it would still do it. I plugged it in to a different outlet, and a different circuit, and it would still do it.

SVS sent me a new amp, but that did it too. So I just couldn't figure it out. I replaced the amp, I changed the electrical source, and I removed all input...

What ended up fixing it was when I put a small surge protector just for the subwoofer in place. The problem stopped and never came back.

My best guess was that some sort of interference was coming through the power line and telling the sub to "wake up" and play the super loud and low sound that was filtered out with the surge protector, but that is just speculation. I have since moved and never had the problem with or without a surge protector.

Just something to try (the surge protector). Keep in mind that a power strip is NOT a surge protector. One will cost you as low as $3 and no nothing but add outlets, the other will actually have some sort of Joules rating on it.

Masta, unplug it for a few hours to let it "reset". See if that helps, as it has with others.

I'm going to try the surge protector idea out and see if that cures the problem. I have tried unplugging it in the past but the problem persists. Very weird problem I have a power conditioner/surge protector on all of my equipment in the rack but not on the sub I've always meant to buy one just never seemed to get around to it. I'll let you know how it goes! Thanks for the info.

Randy should be along shortly...

A quick update. I unplugged the sub for a few days and installed a surge protector the thump thump has subsided and the sub seems to be operating normally for now.

I have two ep600's the other one was plugged into the same outlet as this for some time and then developed the same issue. My children ended up snapping the input off of the amp hence why the other sub which was plugged in across the room was moved to this location. The weird thing is both subs took nearly a year before developing the issue I described. Eventually I will be sending in the first ep600 amp for repair I'm wondering if I should send both? Do you thing that power fluctuations could eventually cause a problem with the amp?

Also I'm wondering why a surge protector and not a power conditioner/voltage regulator would make any difference at all? I always thought they were more of a circuit breaker more like a GFI but tripping on a surge in voltage/amperage when they trip you just reset or replace them? I'm no electrician so correct me if I'm wrong here.

I don't think the surge protector did anything. I think one possible reason it stopped is that you left the sub unplugged long enough this time to reset itself.

Also, if the thump comes back again you are probably looking at something being wrong with the amp that should be checked out.

What is that old Garth Brooks song, and the Thunder Roles. Yes the good old thump thump rumble thump, wow that brings back memories. I remember not to many years ago I said to my wife I didn't think it was supposed to rain. I kept hearing thunder off in the distance. Upon looking outside the skies were clear and nothing but stars.

Went down stairs thinking my paranormal activity had started again from about 8 years ago (MarksJohnson) remember that. Anyway, turned out it was my 600. After unplugging it for some time (can't remember how long) it magically stopped. I think it was some build up of power. The surge won't help as others have indicated, just unplug for an hour or so.

Found it MarksJ

Shows we live in different places, Randy.

I woke up to it at 3 a.m. Thought is was rap coming from a 14-year old Civic out on the main street. But it never "drove" away. Even for rap, the rhythm was a bit repetitive.

I got up, and the instant I left the bedroom I knew it was coming from inside the house. I thought it must be something very bad, because no house system should be doing that. I followed it to my ep500. Oddly, I was relieved, "At least they weren't coming for me again tonight." It's always preceded by a digitally-generated sound, Usually not that low a frequency, though.

It can do that quite erratically, It's 6-years old. It can be fine for 2 years, then it demands attention. It's sort of like Canadian men's nose hair. (Just checking if you were paying attention.) Sometimes, it "vants [sic] to be alone" for a couple of days.

Like an exotic car, or some people, it can be moody. It needs its space and some time.

n.b. I was going to use feminine pronouns in the last sentences, then I caught myself. Why is it that all contraptions; cars, boats, planes, anything conceived, designed and built by men, are referred to as "she?" That's quasi-rhetorical.

Little do you guys know, the thump-thump is actually an Ontario Dock Spider trapped inside.

Yikes. Those things can eat cats and small children.

If you're going to open up the sub, make sure you have a shotgun handy.

Funny, this just happened last week to me after unplugging the sub for a week after a trip. (EP500) I kept thinking there were fireworks going off a few miles away. In my case rebooting solved it.