I am trying to decide between a few used speaker sets I have my eye on. They will be powered with an Onkyo 606 and used for 50% music, 50% movies. My room is 17x23ft with an 8.5ft (at the walls) slightly vaulted ceiling. One half of one of the long walls is open into the next room, and about a third of one of the short walls is open into the entry of the home (a short large hallway).

I'm only looking for a 5.1 system, and have no need nor desire for 7.1.

Here are my options:

1)Polk Monitor 40s, Polk Monitor 30s, Polk CS2 center ~$250
2)Infinity Interlude series IL40 (pair), IL30 (pair) and IL25c (center) ~$650 (this is really stretching the budget)
3)JBL Studio series S312 (pair), S38 (pair), S center ~$350

None of the sets have a sub, so I would need to pick that up separately.

I haven't heard any of these, and some are a pretty long drive away to pick up, so I can't sample them. I'm relying in opinions here!

Thanks guys :)

Would appreciate some comments. I know the interludes and JBL studios are older series.

Would I be better served with Infinity Beta 20 fronts and surrounds, and a beta c250 center? This is also an option in my price range.

I have the Studio series myself. I use 3 S310II's in the front. I've also got the S-Center and S38's (in another room). Many use the S38's as fronts. They're excellent. I really enjoy the sound from all of them (even S36 are nice). I can't speak much for the other speakers or compare them, but I can tell you I'm %100 satisfied with them.

Also, the S312's go down pretty low. If you down that road, try your 5.1 setup without the sub. Run the Bass through your mains. Because they're 3-way, it won't muck up the mids or highs. You'll only need a sub if you want even MORE bass. It's worth a shot.

If you're around Baltimore you can come listen to mine.

I am trying to decide between a few used speaker sets I have my eye on. They will be powered with an Onkyo 606 and used for 50% music, 50% movies. My room is 17x23ft with an 8.5ft (at the walls) slightly vaulted ceiling. One half of one of the long walls is open into the next room, and about a third of one of the short walls is open into the entry of the home (a short large hallway).

I'm only looking for a 5.1 system, and have no need nor desire for 7.1.

Here are my options:

1)Polk Monitor 40s, Polk Monitor 30s, Polk CS2 center ~$250
2)Infinity Interlude series IL40 (pair), IL30 (pair) and IL25c (center) ~$650 (this is really stretching the budget)
3)JBL Studio series S312 (pair), S38 (pair), S center ~$350

None of the sets have a sub, so I would need to pick that up separately.

I haven't heard any of these, and some are a pretty long drive away to pick up, so I can't sample them. I'm relying in opinions here!

Thanks guys :)
See this thread (http://www.avsforum.com/avs-vb/showthread.php?t=1151112&highlight=il40). Its the other thread you started and I responded to it.

The IL series are a great sounding system. I would try to talk the party down a bit unless those IL speakers are in as good shape as mine, which are nearly mint. I've owned the IL40s for about 9 years, the IL30s I bought off a guy on ebay for $200. They were in nearly perfect shape. My IL40s I would guess are worth $400. The IL25 center can be had for well under $100 used if you look around.

The Beta 20s sound almost exactly like the IL30s, and I'm not surprised. They use the same drivers and just a bit different crossover. They can be mixed and matched too. I use a Beta 250 center in the bedroom with the IL30s and the timbre match is perfect. No surprise. Infinity hit on a very good tweeter design with the 1" CMMD driver.

The Studio Series JBL are also a good sounding speaker. I've heard the S310 and S38s. Both are good but not in the same league as the Infinity Interludes IMO. The towers make better bass and the drivers in the Interlude series are some of the best in a mass produced speaker in some time.
I also owned the S Center II for a number of years. Good clear concise center speaker.