So I currently have one of these, but the subwoofer component has begun to take a crap on me. The subwoofer speaker cuts out completely most of the time and will occasionally produce a large pop and crackle *much like interference), and then go silent for another minute or so. Can't find anything on Google about how to possibly fix it, so I think I need to move on.

I want to find something that performs the same function without being too expensive. I currently have two regular car speakers, the two Logitech speakers, and a large amplified subwoofer that is powered by a spare computer power supply, all of which are spliced into a 3.5mm stereo jack. Before today the system put out some pretty good sound and I was happy with it, but I don't even know what to look for to replace the failing Logitech subwoofer. I don't really need another subwoofer, just some sort of amplifier with volume control. Anyone have a suggestion?

The crackle and cut-out is probably due to interference caused by running audio cables next to power cables or other cables. You don't want to route them parallel. Ideally you'll keep power, audio, and video cables separated.

I used to have a minifridge next to my computer. Every time the compressor cycled on my speakers would pop and certain USB devices would cycle (the PC would detect that they were unplugged and then plugged back in). I also had a switchable USB cable so I could use my keyboard on either my PS3 or Wii running near the fridge. When the compressor cycled, the switch would toggle and I'd have to manually switch back.

This kind of stuff will happen with cheaper audio equipment (poorly shielded cables), USB, and other cables. Try re-routing your cabling.

I'm not sure the problem is cable management. It just recently started doing this, despite having my current cable setup for the past six months or so. Also, when I said going silent, I mean the mini-sub goes completely dead. Sound plays fine through every other speaker except for the mini-sub. I also noticed the heat sink on the little amplifier unit inside the sub box was too hot to touch for an extended period of time. Not sure if it has always run that hot however.

I'll try shuffling my cables, however, and see if it does anything.

Edit: No amount of wire-tweaking changes anything. The subwoofer is dead, except for the occasional loud crackle/pop

There are two possible problems, either the amp is done or, the woofer driver is done. To test either, you'd need testing equipment or replacements. Since you already have a car sub, you could pull the driver out of your Logitech enclosure and hook up those leads (from the Logitech amp) to your car sub. If you get sound that doesn't crackle, then you know your problem was the driver.

Well I should have said three possible problems. One of the connectors to your driver could have shook loose and is intermittently touching the connector on the driver. When it touches, it'll make the pop sound and as it slides it'll make a crackle sound, but while it's touching it'll produce music normally.

Is there any sort of audio equipment I can look into to replace the sub/amp thing for around $50? I'm not sure if I have the patience to troubleshoot this $15 piece of equipment.

While you could find parts for super cheap, you gotta know what's bad in order to know what to replace. Do you even want to keep your Logitech sub, or use your car sub and amp instead?

I want to use the car sub as my main sub, but I need something to amplify the other 4 speakers (preferably with a volume knob as well). Just plugging the speakers into the port in my computer produces VERY low sound levels.

Depending on the impedance of each of the speakers, one option could be a single 2ch amp. If they're 8 ohm or higher, you could wire a pair together (parallel) to each channel. If they're 4 ohm, you could wire them in series.

If you need 4 distinct output channels for a quadraphonic surround, then you'd have to have a 4ch amp.

2ch options.
http://www.parts-express.com/pe/showdet ... er=300-380
http://www.parts-express.com/pe/showdet ... er=310-300

4ch options.
Two of the 2ch options ;-)

Anyway, here's the bad news. Any of the options listed above will not control the volume of the sub. This is because the amp for the speakers works independently of the amp for the sub. The only common volume control for them is the computer, so if you turn down the amp for the speakers, the sub will continue to pound away. The only way to make them work together is if you have a common volume or gain control. This can be accomplished with an A/V receiver but in order to get something around $50, you're looking at the used market.

So you either have to suck it up and adjust the volume with the computer, up your budget so you can buy a new AVR, or keep an eye on craigslist for a while till something pops up in your area. Good luck.

Side note, there is this option but I don't know if the sub amp will be strong enough for you, because I know it won't put out the rated power.
http://www.parts-express.com/pe/showdet ... er=310-308

This system would be an upgrade from your current Logitech system and still under $40. Has good reviews too.

http://www.amazon.com/Cyber-Acoustics-S ... =pd_cp_e_0