Multi Ch. speaker placement tips needed



Hello all,

I’m initially setting up a 5.1 system in a < 14ft x < 21ft < 8.4 room. Closed off 100%, save for AC ducts. The ceiling gently slopes up to 8.4 then back down, to about 7.9 ft.

All the speakers are Silverline Audio… Sonata IIs; Center stage; SR 15; Velodyne DD 15. If I add to this config it will be a pair of Minuets for the middle surrounds and another sub for the rears… that has yet to be decided though.

Center surrounds will need to be set onto the side walls if done at all.

Center and mains are set to the < 14ft wall.
Where is the center to sit? On the same plane as the Mains? Or behind them? How high off the floor?

The rears are on Sound Anchor stands and the tweeters are right at ear height, 48 – 80 in.

If I go ahead and add the senter surrounds should they also be set as the rears in height?

Higher? Making for a hemispherical config?

Lower? Making for an increasing slope up to the rears?

Thanks much for your experiences & interest.
blindjim
I'd first find the anchor spot for your listening position, as a fundamental starting point, if it were my system. If you are a "sit-alone" listener/viewer, you have some choices to make in a perfectly symetrical room (in your case, side to side-back to front at least).
In a perfectly rectangular room, with one "centered chair", your challenges are: 1) getting out of all the "holes" in the response curve - 2)knocking down all the peaks as well! - 3) proper acoustical treatment for your room/setup - 4) deciding on whether you can get away with a "long-wall setup" for easier acoustical factors and likely better overall sound - 5)whether or not to go with a "centered listening position" setup or not!
For your room and description (not knowing all your equipment), these are the first factors that come to mind, you should adress - even if that means starting from scratch with your setup.
I mean, in a dedicated room, where you can move things around to optomize, you should! If it's not a dedicated space, with options to move things at will, your main goal is still flat response from all speakers from your chair(s), proper adressing of acoustical reflections from boundaries/walls/objects, etc, well placed speakers for a solid well spread image (in proximation to relative screen size, ifyou can), and yes, proper envelopement and steering. Also, proper phase from all speakers and sub(s) and seats. Room reverb you can't fix without serious acoustic treatments or room DSP correction.
I would first consider a 'long wall" setup for a "first try", as you will most definitely be able to achieve better sound, more easily - due to less first order reflection problems, a lack of acoustical treatment necessities, and closer proximity to your main speakers from your chair. I especially recommend this setup if you don't have money invested in acoustical treatments, and you are a single seat in the room - as opposed to the "short-wall" setup.
You can also get a bit wider with your speakers, and have more flexibility.
That all said, I HIGHLY RECOMMEND some sort of room EQ in ANY SYSTEM these days! small acoustical spaces need all the help they can get, to help balance out the sound. If you're not using any sort of DSP circuit/processor, I recommend the likes of the Rives Parc, high end EQ. All this stuff "adds up".
If you are doing the standard "short -wall" layout, looking down the long dimmension, I'd start with figuring out where you're gunna sit - yes - first. I recommend compromising center position seating in a perfectly symetrical space, because of the problems I mentioned. yes, you give up your center imaging with stereo listening, but you gain so much more with everything else! (infact, I will only do a center position when I can get flat response from my mains and sit where there's not "nulls" in the sound, mainly in "L shapped" rooms)
I'd start by using the 1/3 room dimmension for seating options, and 1/3 or 1/5th width spots for starters. If you want to keep your chair approximately where it is now, just near half mark, I suggest locating the 2/5th's or 3/5ths lenght spot(s), and try placing main l/r speakers in 1/10th length dimmension out from the front wall. Then, depending on where you have your seat from side to side, I recommend placing speakers where they have the overall flattest response in relation to the seat. - trying to balance flat response, proper soundstage width, and proper solidity of immaging. Center should be off of center width, and probably on a 20-24" stand under the image. If you have a perf screen pj setup, you have more options. This should however give you a solid response from the center (also make sure you have a rug between you and the speaker.
sides and rears, I must suggest tring to find locations where they are approximately where you want them (higher up for direct firing speakers, so they don't draw attention to themselves - pulling you away from the MAIN SOUNDSTAGE! (this is distracting, and highly anoying, IMO). You should be lost in a sounscape, not being bombarded with one speaker yelling in your ear!
I would then be finding where each speaker offers the flattest most solid response in relation to your ear position, yes, even the rears and sides! Each speaker should offer solid response and accurate reproduction, as that all adds up to or takes away from the overall sound, and causes tonality problems in the bass, among other problems.
If you can get your speakers placed around you for a coherent, well distributed soundstage, and get flat accurate response (It takes practice and experience - and a test cd and sound level meter are a must), properly deal with the acoustical relfection issues and balance the acoustical treatments for you size room (I recommed - in a shor wall setup - alternating absorption pannels with diffusion pannels, to the sides and behind mains speakers, and diffusion all around the back. In long-wall setup, you might forgot the acoustical treatments all together on sides!), and get proper phase at the critcal crossover from sub and speakers all around, you will have some dynamite sound! *(I notice your speakers are typical stereo speaker desings, with "open tweeter on top" desing. Make sure either sit closer to mains somehowe, or do ceiling acoustical treatments - so you get more direct sound vs. reflected)
All this helps add up to a solid, super dynamic, extremely coherent soundstage!!! fail to consider any and all, and the quality goes down ...it's that simple!
Not sure how this all comes across from how I've written it. But if any questions, let me know.
good luck
The setup is set… short wall. The screen is hung, the PJ is set too. The room is finally shut off effectively during listening/viewing .sessions. The lighting is hung and done. The sound scheme is currently 5.1, though 7.1 might be the end result if I can figure out just where to place the side spkrs.

Now I’m considering dipole/bipoles for the surrounds and directional for the rears. There will be scant little latitude for movement of the rears or center surrounds. Greater flexibility is had with the center ch, mains, and sub.

The listening position is likely to be determined by the 2 ch performance + the visual image viability, and in that order. I’m figuring to do one pair of speakers at a time, mains … rears… then perhaps sides at some later date… then the center and lastly the sub.

Acoustic treatments will follow all the above…. Consisting of corner bass traps, first reflections and possibly some diffusers.

Where it’ll all wind up and how much acoustical treatments are used is anyone’s guess right now.

the biggest variable for me right now is deciding on the use of either dipoles or bipoles as either middle surrounds or rear surrounds.
Hello Blindjim,

I am using a pair of Snell SR.5 bipolar surrounds in my 5.1 system and they seem to integrate very well with my front speakers from a different manufacturer. They mount on the wall (side or rear) and provide very good rear/side fill for surround effects. They provide a wide "dog-bone" dispersion pattern that works well for surround effects. If you are considering bipolar surrounds for your theater you may want to check them out as they are very well made. -jz

Thanks

Snell! That was the name! I had forgotten all about them. But these are pretty pricey, aren't they?