I have an Onkyo 606 and currently have a 5.1 setup:
- Front Speakers are Polk RTi38
- Center Speaker is Polk csi30
- Surround Speakers are Polk FXi30
- Klipsh Sub

I'm am contemplating whether I should purchase 2 additional rear speakers to upgrade to a 7.1 setup. If I decide to do this, any suggestions on the 2 additional speakers?

Are there certain "rear" speakers that I should specifically purchase or do front speakers also work as rear speakers? The reason why I'm asking is because I was thinking about the possibility of moving my front speakers to the rear and buying floor standing speakers for the front. Does this make any sense?

I've never seen speakers that are specifically identified as "rear" speakers (despite that the speakers that I currently own are specifically identified as "front," "center," and "surround" speakers).

First, I should say, as someone who has upgraded to 7.1....it isn't all that much of an upgrade. It can be noticable, and somewhat more enjoyable than a 5.1 setup with some 6.1 or 7.1 soundtracks on DVD and BD. (I'd recommend LOTR:EE, Gladiator, Incredible Hulk bluray as some to hear a difference) But this isn't as big an upgrade as some things.

Front and rear mean nothing. Some cheap HTiBs will claim otherwise, but that is either a holdover from the 1980s (before Dolby Digital) or marketing BS to disguise their crappy speaker design. What does matter, sometimes, is the design of the speaker. Monopole, bipole, dipole, and some other oddball formats exist.

Moving the RTi38s to the rear surrounds should be a decent plan. Monopole is usually the best for channels 6 and 7, although it can depend on your room. Certainly best if you don't have a wall and the speaker placement "creates" the HT area. Finding another pair of FXi30s (or current equivalent) might be another good option for the rear if you have a normal wall in back and the rears will go right on the wall.

You should keep your consistency, though. Try to find some timbre-matched speakers like you already have done. I would also move your FXi30s to a spot directly to the side of your main seat when switching to 7.1, if they aren't there already. Their odd design should be good in that position, esp if you have more than one row of seating.

Spiky's advice is right on for the speakers.

I only have one question, how are you set up now and adding two more speakers to the "rear" does not make this a proper 7.1 setup.

See the material here

http://www.dolby.com/consumer/home_e...omlayout2.html

Yeah. I agree with the 2 above.
I also upgraded from 5.1 to 7.1 but i never noticed that much also.

I went to 6.1 one. Yea one some select disc's I notice. But even then I'm not 100% sure it is better. It is different, not sure about better.