Our stereo receiver is a 2.1 with an impossible to disable 100hz HPF for the two stereo speakers, despite the fact I have really nice full-range speakers (I’m using this receiver because it was free and has TOSlink), so I needed something to do bass. I plugged the RCA lead into an old slightly broken Sony 50w reciever and hooked up a Klipsch speaker that had giant woofers. All was well ‘till the Sony crapped out, and this disaster is my “fix”. I replaced the Sony with a shitty chinese car amp hooked up to all of the 12v outputs of a computer power supply with shorted power leads. It takes four or five tries to get the broken-ass PSU to fire up, but it works great as long as I don’t crank too loud.