Dell 5650 Computer Speakers "build amplified woofer" Questions

...woofer input. It is almost certainly a very simple passive circuit consisting of resistors, capacitors, and possibly an audio transformer or two. Look for circuit on Do-It-Yourself electronic sites ...

woofer (about 26VDC). Is there a schematic available or a part that is most likely bad? Quad amp? other regulator circuitry? if your computer came with a motherboard disc the sound drivers could be on