Subwoofer appears dead but who is to blame?
September 30, 2013 9:54 PM   Subscribe

About a week ago, the subwoofer attached to my Onkyo SR304 receiver made ominous popping sounds even when its audio input signal was removed. First time in 5 years. Now it makes no sounds, but the little green light on the front comes on and the fuse appears okay. Do you think the subwoofer died a natural death, or was foul play involved?---for example, do you think some kind of grounding problem caused its demise?
posted by Napoleonic Terrier to Home & Garden (4 answers total)
 
Best answer: This is hard to diagnose without knowing more, but some anecdata for you:

I have a Klipsch ProMedia sound system I bought used on eBay. The amp is built into the sub, which powers the 5 surround speakers. Everything went out, with a lot of angry buzzing. I found a guy who specialized in fixing ProMedias (they're not made any more but are widely considered to be the best computer speaker 5.1 set ever made, and boy are they amazing).

It ended up being a capacitor on the logic board in the sub. Depending on what's inside your sub (since it's plugged into a receiver, you're not going to have all the amp hardware mine has), it's just as likely that something just died a natural death on its own in there. What sub do you have?

There could've been some electrical issue, but I would imagine that's relatively unlikely, or just as likely that a specific component inside finally gave up the ghost to heat or wear and tear or anything like that.

The guy fixed my board, replaced a bunch of heatsink material, added a silent fan, replaced a WHOLE bunch of caps, and I *still* had a small logic board fail six months later that, fortunately, I was able to pop out and put in the replacement he shipped me relatively easily. Stuff is weird.
posted by disillusioned at 11:39 PM on September 30, 2013


Best answer: but the little green light on the front comes on

I'm taking this and running with the assumption that this is a powered sub. As in, it connects to a line level sub output on your receiver and has it's own integrated amp and possibly even highpass filter.

I've had multiple self-powered speakers die this way, exactly how this is described. I have a pile of very nice powered studio monitors in my storage room and all but one of them pooped out this way.

I opened them all up, and every single one of them had failed the same way. There was inadequate ventilation, and either no automatic thermal shutdown or far too generous of one. Various power amp transistors/other components had completely freaking lifted right off the board. Several had obviously self destructed completely.

Made a list of the parts i'd need to get from digikey or wherever, but never actually ordered them and put them in. I'd assume if you unscrewed the metal backplate of your sub and pulled it out(the circuit board is basically guaranteed to be attached to it) you'd find either a couple blatantly overheated chips with heatsinks attached, or some exploded capacitors. Or just a path of destruction with a melted transistor, a blown trace on the board, and some blown resistors, and just a general fuckmess.(i've seen this too... in a subwoofer actually. ugh)

I would not assume foul play, and i would not pay someone to fix it unless it was a $500+ sub from a really awesome company like velodyne/audio pro/paradigm/HSU/etc. I'd only bother repairing it if you had the wherewithal, soldering knowledge, and general "knack" to do it yourself.
posted by emptythought at 11:55 PM on September 30, 2013


Best answer: sounds like a driver coil meltdown (this happens in lots of devices, not just speakers...my glue gun just did this last week) ...the insulation on the wires is usually just a thin lacquer and heat and age cause them to fail eventually...time for a new speaker :/
posted by sexyrobot at 1:03 AM on October 1, 2013


Best answer: This happened to my powered sub in the middle of the night a few years ago. It sounded like a goddam chopper landing in my bedroom at 3AM. Pretty terrifying, but it apparently isn't super rare.
posted by sanka at 4:31 AM on October 1, 2013


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