Subwoofer Rumbling Randomly

[koberulz]

Comes and goes, whether I'm playing anything or not. Sometimes a second or two, sometimes 10-20 seconds, sometimes even longer. Started a week or two ago, I think?

[Fors*]

Originally Posted by koberulz

Comes and goes, whether I'm playing anything or not. Sometimes a second or two, sometimes 10-20 seconds, sometimes even longer. Started a week or two ago, I think?

I moved your thread to the appropriate forum so you can get a better response. Before we can try to assist you, what type of subwoofer do you have (i.e. company and model #)?

[koberulz]

Didn't realise the subforums got this specific.

Uh, it's a PSB something-or-other. Not sure. Had it for years. Subseries 1, maybe? Looks about the same, at any rate.

Just caught it rumbling despite the entire home theater system being turned off at the moment.

[Fors*]

Originally Posted by koberulz

Didn't realise the subforums got this specific.

Uh, it's a PSB something-or-other. Not sure. Had it for years. Subseries 1, maybe? Looks about the same, at any rate.

Just caught it rumbling despite the entire home theater system being turned off at the moment.

Well, the reason having a model# is to determine certain things, like if your sub has an "Auto-On" or "Stand-by" switch. This means it is basically "sleeping" until it receives an input signal to power the amp and then you hear the rumble. Or it might only have an off/on switch.

Secondly, maybe you have a ground loop issue? Perhaps, the sub might think it is receiving a "signal" when in fact it is the "hum" of the ground loop? Can you hear a slight hum coming from the sub, even when it is off? It could also be the amp...which would be a bigger issue.

[koberulz]

Well like I said, it looks completely identical to this one: https://www.psbspeakers.com/product/...s-1-subwoofer/

And yeah, it's supposed to switch itself on if it receives a signal, then off if it doesn't receive a signal for a while.

I don't think there's a hum when it's off? It rumbles occasionally even with the amp off, so there's that...

[Bluebolt]

Same thing my Polk subwoofers started doing--freaked me out the first time one started rumbling in the middle of the night when the receiver wasn't even powered on. First one sub, then a few weeks later the other began doing the same thing. I had to unplug the subs to get it to stop. Reviews indicated others had the same thing happen; those Polk amps had a tendency to go bad, apparently. Sorry I can't offer a solution. I'll be replacing mine eventually.

[antennahead]

Originally Posted by koberulz

Comes and goes, whether I'm playing anything or not. Sometimes a second or two, sometimes 10-20 seconds, sometimes even longer. Started a week or two ago, I think?

What brand of pre/pro are you running? My SVS sub started doing this a while back, and through trial and error, changing cables, inputs, moving my small sub into the big room from the bedroom, I concluded the problem was my Marantz AV7702.

Searching the internet, I found that spurious, low-level noise was an issue for these Marantz pre/pros after they get a few years on them, and it could be coming from any output channel. In my case it just happened to be the sub channel. Many owners complained about it.

The problem also seems to be sporadic. Mine is currently quiet, but it will probably happen again I'm afraid.

[koberulz]

The amp is a Yamaha RX-860 or RX-760, not sure which.

[DavePS3]

It's most likely the internal amp (assuming you have a powered sub'). Some sub's have two amps inside - a high level and low level. Change both as opposed to one if that's the case. If it's out of warranty and they still have the amps, a lot of times you can swap out yourself since most amp's are attached to the backplate with a clipped ribbon cable. If the sub has the two amps, the secondary amplifier is usually only accessible by removing the driver(s). Kind of a pain to get at. Still cheaper than replacing the whole sub' most of the time.