Blown Sub Plate Amp - leads to creativity

[ratten46 0]

About 5 months ago, the plate amp built into my Klipsch KSW-10 sub died. A replacement amp was $90, but I wasn't really excited about buying that same (55 Watt) amp again. After dragging my feet and trying to come up with alternative solutions and/or uses for the sub, a brilliant plan hatched where I wouldn't have to spend money. So, here's how I got my sub working again....

ThermalTake Silent PurePower 480W ATX Power Supply (18Amps @ 12Volts) - harvested from an old computer and was sitting in a box in my basement.

Rockford Fosgate 200a4 Car Audio Amp (almost old school - circa 1999) - sitting in my garage unused.

KSW-10 Sub - with blown plate amp

First, I removed my plate amp and rewired it. I cut the AC power cord to prevent someone from plugging it in and removed the speaker leads from the output on the plate amp. I disconnected the speaker level input wires from the terminals, then resoldered the sub leads onto one of the pairs of terminals. Viola! Passive sub ready for amplification.

I made the executive decision that I would not need the ATX power supply any time soon (it cost $60 seven years ago and still worked perfectly). So, I opened it up and cut most of the wires coming out of it to about 1 inch length. There were a few wires that needed some attention, so I took care of those specially. The power on leads were given crimp connectors to permanently power on. (There is a hard power switch on the back of the supply, and you will see shortly how I power everything on and off). I left three 12v+ and three ground wires around 2 ft long for my use. The leftover wires (which were mostly 1 inch long) were all capped with heat shrink tubing, then grouped and capped again with heat shrink tubing with zip ties holding everything in place. Put it back together, bundled the 12 volt wires with the nylon loom material that was originally used on the primary 20 pin bundle. Presto! 12 volt DC power supply.

Finally, there's the amp. This was the easy part. Connected the 12V+ remote lead directly to the 12V+ battery terminal. Connected the + and - leads from my new power supply to the amp. Connected my sub output from my reciever to the "front" preamps inputs, and bridged the sub to the "front" speaker outputs.

The power supply gets plugged into the switched output on my reciever. When I turn on the reciever, the power supply starts up, the amp starts up, and the sub gets power. The power supply isn't perfect...it only delivers 11.5 to 12 volts normally, so I estimate the sub only sees 75 watts of power. But...this is well within the safe operating range for this amplifier. The best part is - this repair only cost me 3 hours of time. Everything I needed was laying around my house. Yeah, I know, I should probably put a fuse (or 3 smaller ones) in the 12V+ lines. I didn't take any pics....and it's all hidden in my HT cabinets now...so I won't be fishing those wires back out just to take pictures. Other than that...any comments or suggestions are welcome.

[coobies5 43]

i was going to do this to a old amp i had laying around but i sold it a few weeks ago. so instead i took out the 6.5" woofer out of my 7.1 stereo system for my pc and hooked up my 12" ssd to it, of course a different box instead of the wimpy .8 or whatever cubic foot box it was in. the amp is stable at 4 ohms, so i have my dual 1 ohm ssd wired in series so the amp sees a 2 ohm load which is roughly 30 watts. i cant turn it up too loud or it'll cut off, i'll be upgrading the amp for the sub sometime around summer, but its still good enough for me, night and day difference over the 6.5".

[ABXX49 20]

Cool project. Wish you had pictures. I was very close to doing something along these lines (for fun), but went another route instead.