Need some tech advice to salvage subwoofer

[ttucker329]

I didn't know where to post this.  I have a subwoofer marketed under the klipsch brands.  800watt powered sub that is a low profile design.  It worked fine for about 2 weeks then it developed this roaring sound when it received a signal.  I was playing with the phase controls and also received a mild shock.  I am hoping to salvage this subwoofer, but I don't really know where to start.  Anyone have any ideas of what to check?  Possibly just some bad wiring or a board component?  I'd appreciate any input.

[Paul Birkeland]

Start by removing the amp from the cabinet.

Try powering the woofer from a different amp, even a $5 thrift store receiver will do.  Just make sure that there aren't any odd scraping noises.  Also, meausre the DC resistance between the two wires going to the woofer (should be 4-8 Ohms). 

If the woofer is OK, then pop the cover open on the amplifier and look for things that are out of place.  In particular, look for caps that are bulgy or leaky, as well as for resistors that are burned or completely blown out!

There's also the slight chance that there are four wires leaving the subwoofer, and that they connect to at least three very distinct places on the board.  If this is the case, some additional testing will need to be done.

-PB

[ttucker329]

Thanks for the tip.  The speaker itself appears fine.  I has to be something on the amp board.  I didn't see anything obvious so I guess this will go on ebay as a part out. 

[kgoss]

If you like the sub and want to keep it just look for a plate amplifier from somewhere like Parts Express.  If you can't find one that fits the cabinet opening you could mount it in a Bottlehead like case (like Clark does for the Orca subs) and run speaker wire to the sub.  Just a suggestion.

[earwaxxer]

Here's what I would do Tuck... Can I call you Tuck?. If you like the cabinet  - It sounds like a good one. Get rid of the driver and the amp. Like others have said, get a new sub-woofer driver and an amp from Parts Express. I would stay away from the plate amps. I have gone through 2 of them. Get a Crown. Not much bucks. It will blow away anything you can buy retail. From Parts express I would recommend their Titanic Mk4. I have one.

[ttucker329]

I never thought abouth that. I'll take a look and see what I can find

[azrockitman]

Here's dumb question of the day:
How much effect does the "cone" have on the sound of a subwoofer?  I have a Atlantic Technologies model 262PBM that I'm currently using as my sub with my orcas and stereomour.  It's probably a 10 year old, 250w unit.  The cone was pushed in by some ornery 2 year old.  This happened a few years ago and I haven't used it prior to hooking it up to my BH.

I've been using it for a few weeks and the bass is not that crisp.  It's better than no sub, but not anywhere close to great.  I have no idea if it's due to the cone being pushed in, or simply because it's a very average sub.  I suspect this sub was much more designed to go "boom" for movie explosions, as opposed to being designed for crisp musical bass.

I've been eyeing the new dungeoness sub to mate up with my orcas, but this thread got me to thinking:  The most expensive woofer on Parts-Express is $300 or so....many are in the $200 range....and even more are priced less than that.  Would it be well worth my time to do as Eric suggested for this poster's dilemma?  Meaning replace the subwoofer driver with a new one?  In an extreme case, I could even replace the built-in plate amp if it was not optimally designed. 

[Paul Birkeland]

There's a big difference between a dust cap being damaged and a cone being damaged.

Typically the dust cap is the part that gets pushed in, and that's not exactly the end of the world.

If the cone is pushed in, that can have unfortunate consequences on the suspension.

[azrockitman]

oops, sorry, not the cone.  It is the dust cap "dome" in the center.

[corndog71]

I recommend one of these.  Great for music and movies.

http://www.rythmikaudio.com/F12G.html

[4krow]

As a fan of servo technology for subs, this one looks to be even more useful with addition of a parametric EQ.

[Paul Birkeland]

oops, sorry, not the cone.  It is the dust cap "dome" in the center.

You can cut the dust cap off with an hobby knife and glue on a new one.
If you glue on a metal one, perhaps you could connect it to the mains to keep the kids away.

[azrockitman]

 
one touch and he would never do it again.

[earwaxxer]

My Phoenix friend. Do NOT be afraid to HACK out that old driver and put an new one in... You will be surprised. Nothing to it. Try to get a replacement that fits it exactly, but thats not even that important. Whether it fits into the countersunk spec or not is not a biggie. My last driver is glued to the outside lip of the driver hole. Just glue it GOOD with some high power shit. Modern drivers are frickin heavy. Good performing stuff though. I think I spent $175 on my driver and about $250 on the crown amp, run in bridged mode gives me a bit over a 1KW. Kicks ass.

[2wo]

Yea, these Subs are more for explosions than music.

Eric makes a great point of replacing the driver. rip the old one out and measure the inside of the box, best you can and if it has ports or not. Maybe we can suggest a different driver to try, something less output, more musical...John