R50 or Monitor 40 as surrounds?

[frodaddy]

Hi again! I have been using my Monitor 40's as surrounds lately. However, I have purchased some RT800's to replace my R50's for front L/R duty. So this means I will have the choice of using either my Monitor 40's or R50's as surrounds.

Currently my Monitor 40's sit about 8 feet off the ground on my back wall. They are positioned behind the main seat which comes to about 135 degrees using the TV as the 0 degree mark. I found that the best sound and imaging happened when I aimed the speaker downward at the main seat.

I know there are plenty of people that use floor standing speakers as surrounds, and the main issue is imaging since the tweater will be at ear level. I have some stands that I can elevate the R50's 16in to compensate for this. Also, by using the R50's I can position them to dolby/thx spec which is 90-110 degrees to the side of the listener.

Finally I'd like to add that I run all my speakers full range. So what is everyone's opinion on this?

[frodaddy]

I went ahead and tested having the R50's as surrounds today. I have them on 13" stands positioned at about 100-110 degrees.

What I noticed about this setup was sensitive to closeness and toe-in. The delay time would not correct the effect I was getting when the right rear was around 4ft from my ear. It sounded like I had headphones on, and it was distracting me from the other channels. (I adjusted channel levels after every change I made.) After I moved the surround speakers as far out as I could (5-6ft), it cured the headphone effect. However, imaging was still "off" in such a way that rear left/right pans and rear combination effects didn't sound precise. I adjusted the toe-in of each speaker and found that rotating them by just a centimeter would make a big difference. Again, I was surprised how sensitive this setup was to such small changes. It took a little while to get used to the new sound, but it sounded much better than anything I've had in my home thus far.

I found that having the R50's lower frequency response in the rear was dependent on the source material. That might seem obvious, but I found that only the most recent DVDs sent full range material back there. Older soundtracks sent info back there, but it was mostly high range material. Having the fuller surround speakers was very noticable with War of the Worlds. The scene with the bridge being demolished at the point when the bridge hits the pavement had some noticeable low frequencies that was playing through the surrounds; this was without interference from the LFE channel. Also when the orchestral music was playing throughout the movie, most of the time they shoved it through the surrounds more than any other movie I've heard lately. So War of the Worlds was a good movie to help me make my decision to use floorstanding speakers in the rear.

I figured I'd reply to my post since I found the answers I was looking for myself! I hope this helps someone who is on the fence about floorstanding speakers as surrounds.

[AzN_plyR]

cool, good to know, BTW, are you running a subwoofer?

[mrbigbluelight]

I haven't noticed the effect of newer DVD's like War of the Worlds sending full spectrum to the rears, probably because I'm using R30's as rear surrounds.
They, of course, don't have the lower end of the R50's which may be why I haven't noticed it. The mid/tweeter juices flow quite nicely, but my sub, the "Mighty Athena As-p4000" provides very nice omnidirectional lower end.

My R30's aren't elevated, and are technically a little too low. But if I recline the Lazy-Boy to the full horizontal position, the R30's are firing just slightly over my head. Overall effect is fine.

[frodaddy]

AzN: I have an infinite baffle subwoofer setup that consists of four Dayton IB 15's. Here is a website about that type of setup: http://ibsubwoofers.proboards51.com/index.cgi

I just listened to the "depth charged" scene in U571 and it had some low end in the rears in it, too. So I guess it's not restricted to newer movies, but maybe the newer ones have better soundtracks.