Welcome to the saloon, lsjdesigns. I'm afraid that Bose users are few and far between here (I owned an Acoustimass setup at one time, but upgraded my speakers to Paradigm back in 2001 and never looked back). My knee-jerk reaction to all things Bose is to cringe and steer people away, but I'll resist that for a moment. I'm basing my comments solely on the manual , but maybe it'll help.

From what I can tell, you must have the Acoustimass module that comes with the Lifestyle 5 - basically, the Lifestyle module appears to be a pre-amp only, while the Acoustimass unit has the amp channels for both itself and the two speakers. There's also a "system control" connection between the Lifestyle and Acoustimass, and I have no idea what the purpose of that is. If the Lifestyle unit really is just a CD player and a pre-amp, you could put a separate power amp between the Lifestyle module and your speakers, but there are two caveats to the. One is that if you want to use your Acoustimass 5 speakers with a power amp, you may have wiring issues - most of Bose's speaker stuff has been moving toward RCA connectors for the speaker connections, which nobody else does, so you'd have to cut the connectors off. (On the bright side, if you have the regular Acoustimass 5 package, I think the wires that go to the bass module will have the normal +/- leads on the ends that could be connected to an amp.) The second caveat is that a separate power amp will cost several hundred dollars that would be much better spent by replacing the Lifestyle unit with a proper receiver.

Does that help?

I'll finish with a wholly unsolicited suggestion: you will achieve much better sound from some less expensive equipment if you go with a brand other than Bose. There are some quite respectable receivers on the market for just a few hundred dollars, or you could even get Outlaw's RR2150 ($600) and have an exceptional stereo receiver capable of driving most speakers. Good bookshelf speakers (a little larger than Bose's cubes but worlds better sounding - I speak from having owned Bose cubes, by the way) can be had for as little $300 or $400. If you're just getting started, it might be worthwhile to do a little poking around into the alternatives. And if you do decide to switch away from Bose, you can thank their rather frightening marketing department for one favor: Bose stuff holds its value absurdly well, and you can get a significant percent of the original price by selling it on eBay.