Stacking speakers (tower + bookshelf)

[Curtis]

I have a pair of JBL tower speakers and Klipsch bookshelf speakers, and I'm very pleased with the performance of each of them. I've been using the JBL towers for home use and the Klipsch bookshelf speakers for dorm use. However, I've brought the bookshelf speakers home for the break, and have since been mulling over the issue of how to incorporate them into my system (if at all). It should be noted that my amp (Onkyo TX-5811) has more than enough juice for both of them.

Would stacking the speakers be a good idea? My main concern is whether there might be a problem with some kind of interference effect from the two acoustic sources, especially since the set up will be mid tweeter mid tweeter. If I do stack, is it better to stack [L/L, R/R], or [L/R L/R]?

Or...would it just be better to use the bookshelves as backs? This is a stereo system, so surround sound isn't a factor.

[Kevio]

Combing a good sounding speaker with another good sounding speaker is unlikely to make a better sounding speaker. It will likely make a louder system. It might look impressive. It might be fun.

You want to wire the speakers in parallel to the amplifier or if your amp has A/B speaker selection capability, wire each pair separately to the amp as A and B. Be careful not to get too excited with the volume and blow something out. The relative loudness of the two sets of speakers will be determined by their individual characteristics (impedance and sensitivity). As you increase the volume, you may end up pushing the bookshelf speakers to the edge while under powering the JBLs.

[Curtis]

That's exactly what I did. Just to be absolutely certain, since each pair of speakers has an 8 ohm impedance and they are wired to the amp in parallel, I should set the amp for 4 ohms right? The bookshelf speakers are also wired through a subwoofer (amp wired to sub through the A speaker terminals, sub wired to bookshelf speakers). I'm not sure that this will make a difference (I don't think it should).