I think it's time to start a thread discussing & promoting the use of DIPOLE surround speakers in 5.1 and 7.1 systems.
I've used many different types of speakers as surrounds. But until recently, I always thought that regular front-firing speakers were better for the surrounds, as they were a closer match to the fronts.
Damn... was I wrong!
After trying out a few types of dipoles and bipoles, I wonder why everyone doesn't have dipoles in their system. I'm also amazed that more hi-fi shops don't sell or push them... or even KNOW about them, as is all too often the case here in Australia !
A good bi-pole speaker will have two sets of drivers facing away from each other, firing sound out into the room. This sound will then cover a wider area, and bounce off the side and back walls, helping to create a bigger sound that allows more people in the room to "get surrounded".
The same as bi-pole , but the drivers on either side of the speaker will run out-of-phase with each other. THX recommend this. The advantage is that it's harder to tell exactly where the speaker is as it sounds more diffuse. It's also harder for you to get ear-bashed by one of the surround speakers if you're stuck sitting off to one side. So opens up the "sweet spot".
So here are some advantages...
1. A wider, bigger sound - much closer to the result you get from multiple surround speakers in a movie theatre.
2. A much wider listening sweet spot for everyone in the room.
3. They're easy to wall-mount.
4. They're often more compact than a regular bookshelf speaker, and a lot more wall-friendly.
Here's an interesting shoot-out between dipoles and front-firing speakers. There are six pages with pictures. This will link to the summary...
Here's some more blurb: "The Case for Dipole surrounds":
One issue dipoles can have compared to bipole or front-firing speakers, is reduced bass. This is because the bass drivers are running out-of-phase with each other. Be aware though, that several manufacturers make dipoles that avoid this problem....
PARADIGM really know how to make great surround speakers. Their ADP190 would have to be my favourite all-round surround speaker for the majority of people. Paradigm design all their surround speakers so that the deeper bass is kept in phase....
MONITOR AUDIO also make nice surround speakers. The less expensive models have only one bass driver, but they can be switched between dipole and bipole, like this one...
JBL make some THX-approved models...
INFINITY make a unique speaker called the ES250. I own a pair of these. They can be switched between dipole, bipole and dual-monopole, where they operate as two separate speaker channels in one wall-mounted unit. Handy for 7.1 where you can't mount rear-wall speakers....
JBL now make one just like the Infinity...
ANY OTHER THOUGHTS OR SUGGESTIONS?
Edited by Electric_Haggis - 9/17/12 at 5:06pm