Originally Posted by deepstang
Electric_Haggis...great thread!! It is interesting how in 2007 when this thread was on fire, (1) although bipole and dipole was defined, half the posters used the term bipole and dipole interchangeably, (2) I felt that it was not really clarified or recommended to use bipoles on a rear wall (especially if seating is close to the rear wall) and dipoles on side walls. If I am not mistaken, that is what a lot (if not most) AVS members currently recommend. Actually, a lot of the suggestions that were made was to use dipoles on the side and back postions.
To clarify, I want to bring up the specific (and common) scenario of when the main seating postion is along or close to the back wall of the listening room/area. The advice that I have heard that it is best to have a 5.1 set-up and use BIPOLE speakers positioned wide on the back wall, 2 feet above the listening plane. If dipoles were used on the back wall the sweet spot would be small and more than likely the listener would be sitting in a null.
Further back, I posted a pic of the 7.0 setup in my old place.
If you click on my signature, you'll see that the new place pretty much fits your description.
I've gone through many different types of surround setups over the ages - dipole, bipole, towers, bookshelves and combos of each. Nine times out of ten, a 7.0/7.1 setup with bipoles/quadpoles on the back wall, and bipoles, quadpoles or dipoles on the side walls is the way to go.
If my side walls permitted it, ideally I'd cram in a pair of either Axiom QS8s, or Paradigm ADP-190's.
Alas, they won't quite fit. But I'm getting surprisingly good results running the Infinity ES250's in dual-monopole, with some bounce off the side wall/window helping somewhat.
If you can't accommodate speakers on the side walls, then I'd strongly suggest you either do what I'm doing, or even better - have 4 separate speakers along the back wall (the Axioms would probably be the best for this).
Dipoles are a little finicky about where you place them and where you sit.
If you can't place them on either side of you and consistently be able to sit in the null-zone, then most of their benefit is lost, and you can often end up with "phasey" sound and less spaciousness.
At any rate, the common problem with dipoles is when the woofers also run out of phase, resulting in compromised bass. So if you do use dipoles, make sure they're something like the Paradigms, which only run the tweeters out of phase.
I'm usually finding that matching quadpoles or bipoles are better for the sides unless you're forced to sit uncomfortably close, in which case dipoles can help.
It really is a try-before-you-buy situation...