Subwoofer static, boom when plugged in

mudixon

I've owned a RM 6600 speaker system, complete with the PSW350 subwoofer, for many years and I absolutely love it.

Earlier this year, the PSW350 needed its amp replaced because I bought the wrong fuse and blew it up! Well, it didn't blow up, but it obviously damaged the amp. (Lesson to all on taking care of fuse choices!) Polk sent me a replacement amp and I installed it without issue. It has been working fine ever since. Until recently.

I always unplug my entertainment system whenever there is a chance of bad weather. Recently, when I plug everything back in, the PSW350 makes a horrendous sound of electrical static, fizzing, hiss...followed by a loud low-end pop that shakes the floor. Then everything is fine and silent...and the subwoofer works as it should. I never hear any of this noise except when plugging it back in. I've tried plugging it in separately from the protected power strip, and plugging it into a separate recepticle. The outlets have all been checked and are not having any issues.

Is any of this noise causing damage to the speaker? Is this something that should be expected? I could record what this sounds like if that would help. I just want this fixed. Thanks!

Mike

thuffman03

My Sunfire makes a pop also. Not like what you are experancing but it does this when I unplug it but not when plugging it in. I had a Definitive Technology Prosub that would do what you are saying on both the power down and power up when pulled from the wall but not an floor shaking thud just a small one.

Not sure what causes that but hope someone can shed some light on this.

thsmith

Not sure what the problem is but hopefully you turned the sub OFF before yanking any cables. Turn it off not leaving it on auto.

After re=reading your problem I bet if you manually turn the sub off then remove power and then restore power and turn sub back on or to auto you will not hear any noise.

mudixon

Thanks thuffman03 and thsmith for your feedback!

to thsmith: I always turn off the subwoofer before unplugging or plugging it back in. Even with the sub off, when I plug it in, I immediately hear this awful noise...always ending with a sub-level thump.

thsmith

Interesting, My SVS does not do that. When you power the sub back on is the AVR already on or off ?

Might try it with RCA unplugged from sub.

mudixon

When I plug in the sub, everything on the sub is turned off. I have tried making sure everything is unplugged from it (RCA) but that doesn't seem to make a difference. Ugh. :-)

thsmith

So even with the sub off you are getting the thumps and so forth when you plug it back in ?

mudixon

That is correct. The sub can be off for many days, but when plugged back in (even with its power turned off and nothing plugged into it), it still gives me the noise and thump when plugging back in. The funny thing is, after that 15 seconds worth of noise, it works fine and never gives me that noise again (until I plug it back in). Unplugging it doesn't trigger any noise.

thsmith

Exhausted my knowledge, might call Polk Customer Service and see what they think.

kcoc321

Strange.....what about plugging sub into a power strip that is plugged in but switched to off. Then turning the sub on with the switch on the power strip.

Seems like you are getting some kindof of power surge.
Either that or it is just some capacitors in the amp powering up....???

What about trying with a 'cheater' plug? Which would eliminate any ground loop issue....

interested to see what CS has to say? Please let us know.

Face

I had something similar and a cheater plug didn't help. I had to ground the sub to my receiver. In other words, I ran a wire from a bolt on my plate amp to the grounding post or a chassis screw on my receiver. YMMV.

mudixon

Thanks for the suggestions everyone.

kcoc321: I've tried plugging it into a power strip just as you indicated but there's no difference in the result. As soon as the sub receives power, it makes this series of noises.

Face: I'm not sure what a cheater plug is, but you would think that consumers shouldn't have to ground a subwoofer, eh? :-)

I haven't heard from Polk yet (thought they'd respond here in the threads...but I guess I'll have to contact them directly). I will follow-up here when I hear something, but I'll still monitor this thread.

treitz3

mudixon, they may not have checked the TS section after 3:30PM. If they don't respond in the morning, feel free to give them a phone call. 1-866-764-1801 You'll most likely get a quicker fix that way. Good luck.

The image below is a cheater plug, FYI.


Oh, my manners...welcome to the Polk forum.

mudixon

Thanks treitz3! So THAT's a cheater plug. I definitely recognize that. Still, one would think this shouldn't be necessary. We'll see what Polk says tomorrow!

-Mike

treitz3

You are welcome. I personally do not recommend a cheater plug but in some cases they will remove noise.

mudixon

I received a note from Polk support this morning and wanted to share it with everyone...

"From your description I would imagine there is a problem in the bass amplifier's power supply. When the unit is unplugged (as opposed to being in standby) the power supply is completely shut off. When re-plugging the power cord the power supply turns on and the bad sound is the result. Your replacement amplifier came with a one year warranty and you appear to be within that period. It would be best to remove and package up the amplifier and send it..."

So I guess I will be without some low end for a bit while I await a new amp!

thsmith

There you, excellent Polk CS. You may want to describe to them what you do when you are preparing for a storm for power down sequence recommendations.

jacob.simpson

Great, proves again about great CS from Polk, and most of us should realise especially newbies and those who whine, that it pays very little extra to buy from authorised dealers.