Wire satellite and sub in parallel off of amp without sub pre-out?

How about this amp instead?

http://www.parts-express.com/pe/show...number=310-308

I actually have the 2.0 amp you linked, works well, but a 2.1 would be a better choice for your situation.

Yeah the reviews are mixed I see - not sure what else to recommend that has such a nice price. I'm in the same boat, using the Lepai amp connected to my PC, and would like to add a sub - one other thing I was going to check was a modest used AVR (eBay, craigslist).

Or maybe you could what you're suggesting by adding an impedence matching speaker selector? Don't have experience with them, but was just looking into them last week - to be able to audition multiple speakers and A/B test.

Well, it's a bad idea to wire two sets of speakers in parallel when the particular amp is not designed to handle the lower impedance that results, but with a suitably capable amp (not sure about yours) it works fine.

As for what you're suggesting, first let me say that I've never tried it and am not an expert on amps, so I won't guarantee anything--you must assume all of the risk of whatever you may try. That said, I would expect that the speaker-level inputs of the sub would have rather high impedance (typically in the thousands of ohms), as they are not supposed to draw much current (ideally none). This will only lower the impedance seen by the amp by a small amount, which shouldn't do any harm as long as your speakers are nominally 8 ohms. Then again, there are few things as dangerous as having a little knowledge.

By the way, what line-level input(s) does your sub have? If it has both left and right inputs, then you could use a Y-splitter to parallel the signal coming from the source device between the amp and sub. On the other hand, if your sub only has a single line-level input, then you'd need a separate summing circuit (do NOT use a Y-splitter to combine the left & right channels!), so you might as well try hooking everything up like you originally suggested.

Yes, you'd have to use your PC's volume control in that case. And by the way, I meant that two Y-splitters would be used to split both the left and right channels.

If you'd rather use the volume control on the amplifier, though, then try it the other way (parallel connection to the amp's speaker-level outputs). The odds of something going wrong are slim, in my opinion--the subwoofer's speaker-level inputs would have to be incorrectly-designed or defective for anything bad to happen. If somebody knows better, then please speak up now.