Polk RM8 As Rear Surrounds in 7.1 Setup?

NeedingInfo

Hi All:

While I have found several similar questions around this topic, they differ enough from my query that I feel I can ask again

I am setting up a 7.1 system. My electronic gear is all THX certified, btw. I have 2 LSI15s in the front, LSIC in the center, 2 LSI9s on the side (I need good surrounds for multi-channel SACD). I have a pair of both the RM7s and the RM8s, and want to know which to use for the rear surrounds (not for music - theater only).

I know what Dolby and THX have to say. My issue is that, while my sofa is just barely far enough from the rear wall to allow for 7.1, the only place I can mount the speakers is about 3 feet to the left and right of the sofa. Thus, the angle of approach is not quite behind the listener. In fact, at this angle, the surround backs could just barely be acceptable for 5.1 side surrounds!

So, I am wondering if mounting the RM8s on the rear, facing the center of the sofa, and with the radiating sides pointing inwards towards the wall, might give me the "rearward" surround effect 7.1 is supposed to deliver. Alternately, I guess I could just use a center speaker directly behind the sofa and go 6.1, but as I already have the RM7s and RM8s...

Thanks in advance for any help.

NeedingInfo

anyone?

Eric W

It may sound kind of strange in that configuration- you have full size bookshelf LSi9's for the surrounds and the complementing LSi series for the fronts- but then you throw the RM8 into the mix- totally different series, totally different sound.

Try both 7.1 and 5.1 configurations and see which you like. In my experience, the properly matched 5.1 may sound better then the 7.1 with the non-matching rears. All too often, users may try to "force" a 6.1 or 7.1 by using improper speakers in improper positions when it just doesn't blend properly.

But- as most things in audio- there's really no right or wrong way to do it.. just whatever sounds best to you.

zx_toth

I agree with Eric. If you already have the 5.1 setup it would take little effort to shift the LSi 9s to the sides a bit more and temporarily integrate the RM8s in and see if it adds to your experience or just detracts. Certainly close listening would reveal a drop in quality of sound as a continous sounds travelled around your room ... would this be noticeable enough or would it not?

Give it a whirl and let us know. If you didnt like it you could save up for a single LSi 7 or 9 for a rear 6.1 channel and than eventually save for a fourth in time or when used items came up... small steps.

I am in the midst of deciding what route to go as well ... I have a pair of LSi25s for front, LSiC and a whole lot of RMs (pair of 20s and 30s) that Ive been thinking of using in a 7.1 setup or wondering whether I should hold off and get the matching LSi surrounds. My surrounds have been in boxes for 8 months now wondering .....

Good luck.

Zsolt

NeedingInfo

I will try and report back. I must be honest and respectfully explain that I am not convinced that the use of different series on the rear surrounds should make much of a difference. Assuming that music (SACD, DVD-A, etc) will always be 5.1, than the rear surrounds should only be producing effects. None but the most trained would notice the difference in "fidelity" (and I use that word loosely).

I previously had the RM8s on the sides and wanted to go to Lsi9s as my SACD playback suffered too much. Now there is an area where the different series really mattered!!!

If I were to restate the question, would it make a difference? What if I used RM7s for the sides (instead on LsI9s)? What would the consensus be regarding the RM8s, in the configuration I speak of, then?

Eric W

It will also depend on what mode you have your processor on. Even though the SACD and most movies etc are 5.1, you can set the processor so that A) the surround backs are off The surround backs play the same material as the surround sides or C) the processor uses the material from the L and R surrounds to matrix the content for the surround backs.

My personal experience- I had a pair of Dipole surround L and R speakers. I had another pair of high quality, but different branded monopole speakers I put in the rear wall for the 7.1. The timbre difference was quite noticable and painfully obvious, even on movies that were "only" effects. Not to mention my setup was at optimal positions too- proper and equal height of surround speakers, seating area not backed up against the rear wall, speakers positioned ideal angles.

The RM7's would match the RM8's much better then the LSi9's. However, they're not nearly as good sounding as the LSi9, it's simply not the same caliber and won't match the fronts. In other words, the RM does not even remotely match the LSi.

By adding the any of the RM's to that system, you're going from a properly matched ultra-high quality 5.1 system to an unmatched hodgepodge of sound. LSi was designed (and priced) as a no holds barred, best quality speaker system. While RM is much more budget minded for someone looking to save space and visual impact.

You're right though, if you're having movie night and someone who is not enthusiastic about HT is over it's doubtful they'd take notice. But the system is about you... do whichever sounds best to you.