I'm going to be getting some bookshelf speakers, something like the Bose 201 series, and a receiver to match the speakers. However, the receiver i'm planning on buying has no sub output. Is there anyway I can hook up the sub to the receiver? I've hooked my sub to my friend's speaker system using the headphone jack into the amp for my sub, but that's probably not the best way to do it. The sub amp I have is an instrument-grade Mackie 1400i. Thanks for the help folks.