What kind of rear speaker?

I'm putting together a HT for my father, and am new to the whole dipole/bipole vs. direct radiator debate. I've spoken with company tech supports, dealers, etc. Everyone appears to say that the debate has been settled conclusively, but they don't all say that the same option was the conclusion! Some claim that rears are really for ambient sound, and so you should go with dipoles on the side or bipoles in back. Others say that was in the pro-logic days and that dolby digital and dts, with their discrete rear channels, require a direct radiator. With different arguments out there, I imagine I'll get different arguments in here. All opinions would be welcome, though. I've searched the forum archives to no avail. I might even consider changing my own system. I'm looking at either a Kef or Paradigm system for my dad (around $3k for speakers and receiver), and have 3 to 5 hundred for rears. Paradigm mini-monitors vs. ADPs? In my own system, I use Snell C/V front and Snell XA55 center. I'm currently using some Energy C6 floorstanders for rears. Would a dipole work better, or even a bookshelf monopole? Thanks in advance.
Direct radiator is ok as long as you have a larger size room. It will give itself away if you have to place it to close to any seating. With multichannel music now being used in a lot of systems the debate will fire up again. Try both and see what you like.
My listening room is of moderate size, and I don't really have an acceptable way to mount speakers on the sides of the room, so my surround speakers are located behind the listener. After experimenting with both direct radiator, dipole, and bipole speakers, I eventually settled on a compromise that works very well in my room: M&K SS150 THX tripole speakers.

The M&K SS150's have drivers on both sides of their angled cabinets, so they act like dipoles, but they also have a somewhat larger driver on the front panel, which provides direct sound. The speaker also has provisions so you can adjust the relative balance between the side drivers and the front driver, thereby changing the distribution pattern of the sound. I have found this speaker to be nearly ideal for my needs, and it is sufficiently flexible that it can be used in almost any placement configuration.

The SS150's aren't cheap (MSRP is $1200), but M&K now has several similar models that are a good deal less costly. I was able to find a used pair of SS150's for $500 here on Audiogon, and at this price they were an excellent value.

For more info about M&K's full line of surround speakers, go to their Web site at the following link:

As an aside, the Snell surrounds are excellent also. Snell has a tripole similar to the M&K SS150, which I seriously considered (I think the MSRP is $1500/pair). I chose the SS150's mainly because I was able to get a good buy for a used pair, but I also thought they offered a bit more flexibility in my listening room.

I agree with Sdcampbell, try the M&K's. I am currently using a Tripole surround(M&K Tripole K4) and works very well on my current set up. The price for a pair is $400 brand new.