In-wall center: Above or below proj. screen?

CNWDI
CNWDI Posts: 91
edited May 2011 in Speakers
Currently trying to fit things into a non-dedicated HT and realizing that there will be some tradeoffs in wall space. Due to ceiling sound proofing I only have 91.5" from finished ceiling to unfinished slab, and ~72" between finished ceiling and the top of the electrical outlets on the main wall where the projector screen will go.

I'd thought that there would be plenty of room for center channel (CC) speaker and screen on that wall, but it's not that easy. The hang-on-wall screen I'm looking at is 66.7" high, and the speaker grille (Polk 255c-LS) is 9 5/16"...which implies that I have only a few options:
1. Put the speaker up above the screen, and let the screen overlap electrical outlets (and be so close to the floor that anyone who moves will interrupt the projector beam).
2. Put the speaker below the screen, and have the CC so low that folks in the front may affect sound for anyone sitting/standing further back (the room is ~19' wide and > 40' long.)
3. Try to build some sort of angled box to hold the speaker at a 45 degree angle above the screen.
4. Use some other screen, possibly entirely DIY or a much more expensive Acoustically Transparent (AT) screen.

I really would prefer to stick with the screen I'd picked, since it seems to be a very good fit in features and price (<$700 for a 120" diagonal 16x9 with built-in masks for 2.39:1) for what I was seeking. An AT screen might be a good compromise, but could be expected to have at least some effect on acoustic quality and picture quality.

If I could find a Polk center channel of similar quality to the LSi series that was <5" tall that would be wonderful...but I don't see any. Right now I'm actually considering trying to build a box and angle the center channel down...so I'm looking for any suggestions as to how bad an idea that would be, or any alternatives I've not considered sufficiently, or really any related thoughts. Thanks.
EDIT: fix typo.
Current polk speakers:
Family room 5.1: TC265i R/L, VM10 Center, RC65i surrounds (couldn't match the TCs)
Basement non-dedicated 7.1 HT: SDA-CRS+ R/L, 255c-LS Center, LSiFX surrounds, RC80i in-ceiling rear surround, plus Wharfedale 12" sub (some day I'll get around to building 15" F-20 sub).
Post edited by CNWDI on

Comments

  • Sherardp
    Sherardp Posts: 8,038
    edited May 2011
    Couple of options come to mind. You could use a stand like the Lovan M2 center stand which is what I personally use in my theater. It allows you to angle the center toward the back row of seating which works out perfectly. You could use that paired with the LSiC below the screen.

    Next option would be mount the screen centered as planned, and run dual centers top & bottom using a pair of bookshelf speakers. That would work and give you great sound, no problems. It's been discussed here and has been done with excellent results. Again you would have to try and angle (B-tech 77s would work) them toward the sweetspot.

    Last I would propose some sort of in wall mount that would allow the speaker to tilt upward, think swivel. If your planning to mount that center below the screen you will definitely want to angle it upward. In own experience I had my CSi5 below the screen on the floor and it just sounded lifeless (muffled). I purchased the Lovan M2 and it definitely gave me the sound I knew the CSi5 is capable of.

    Let me know what you think, sounds like a nice room. Would love to see some pics.
    Shoot the jumper.....................BALLIN.............!!!!!

    Home Theater Pics in the Showcase :cool:

    http://www.polkaudio.com/forums/showcase/view.php?userid=73580
  • CNWDI
    CNWDI Posts: 91
    edited May 2011
    I'll work on pictures...just got the LSiFX speakers up on the wall tonight but the room still looks very unfinished.

    The center channel I'd planned and purchased, though, is an in-wall (255c-LS)...so stands don't work. I also didn't wire (nor budget) for top-and-bottom center channels, but you're right that that's another alternative to help the center imaging--particularly if I do end up angling the top one down.

    If I run a separate wire for a second center channel speaker (since the baseboards aren't yet in) what's the best way to pre/amp this? Take the single center channel output, split it at pre-amp levels, and then feed it to two amp channels one for each speaker? I'm considering:
    - Mounting the in-wall center channel in the wall for now.
    - Running a second set of cables for a second CC speaker below the screen
    - Purchasing the originally planned screen, and putting it "up on blocks" at the height it would end up under the in-wall center channel to see how that works with the projector mounted and with people moving in the room.
    If the projector then needs to move further up, then I pull the speaker out of the wall, drywall over the opening, and mount a box on the wall to angle the in-wall speaker downwards

    If the sound needs improvement, then look at putting the second center channel in below the screen.

    Or am I just supposed to switch to an AT screen now?
    Current polk speakers:
    Family room 5.1: TC265i R/L, VM10 Center, RC65i surrounds (couldn't match the TCs)
    Basement non-dedicated 7.1 HT: SDA-CRS+ R/L, 255c-LS Center, LSiFX surrounds, RC80i in-ceiling rear surround, plus Wharfedale 12" sub (some day I'll get around to building 15" F-20 sub).
  • mantis
    mantis Posts: 17,204
    edited May 2011
    All good suggestions but I have another. Buy a Micro Perf screen from Stewart. They allow placement of a center channel behind the screen. You can build the center channel in the wall as planed and not even see it. It can be placed dead center of the screen which is exactly where it should be.
    I honest prefer the center channel above the screen when at all possible. It sounds more natural and like the sound is coming from the screen instead of a speaker. When I have to mount them below , I basically touch the bottom of the screen or come within 1 to 2 inches max.
    You can place the screen slightly higher if it has to go below and get the center up as high as possible. With multiple rows of seats , the back rows suffer when the center is below unless you have it angled perfectly.
    Just remember speaker placement is key to a win or lose system.
    Dan
    My personal quest is to save to world of bad audio, one thread at a time.
  • Topper
    Topper Posts: 403
    edited May 2011
    Hi Mantis - if we place the center speaker above the screen, wouldn't it be far higher than the front left and right speakers? (i always thought the closer the horizontal alignment of the center and left and right, the better the experience?)
  • Sherardp
    Sherardp Posts: 8,038
    edited May 2011
    mantis wrote: »
    All good suggestions but I have another. Buy a Micro Perf screen from Stewart. They allow placement of a center channel behind the screen. You can build the center channel in the wall as planed and not even see it. It can be placed dead center of the screen which is exactly where it should be.

    An excellent idea but your talking 2-3k on a screen alone. Stewart screens are great, but 2-3K great is bit over the top if you ask me. I think Monoprice carries AT screens so that maybe an option.
    Shoot the jumper.....................BALLIN.............!!!!!

    Home Theater Pics in the Showcase :cool:

    http://www.polkaudio.com/forums/showcase/view.php?userid=73580
  • CNWDI
    CNWDI Posts: 91
    edited May 2011
    Thanks to all for your thoughts and typing time. The measurement I realize I left out above is that even though the room is ~18' wide, there are casement windows that take almost four feet off each side...in the end I've only got 129.5" usable between the windows for a screen.

    The original plan was for a 120" diagonal Monoprice "Multi-Format" screen that does "constant image width" -- 16x9 default along with manual masking to go to ~2.40:1. The outside dimensions end up being 112.4x66.7" - which is fine on width but *really* low on height unless I mount it flush with the ceiling. Upon further review, though, I'm realizing that as much as I want a big screen, I also don't want a screen that goes all the way to the floor and _no_one_ can move (without blocking the light) once the movie/game is on.

    Given the room geometry (limiting factors of both floor-to-ceiling height, and distance between casement windows my wife won't let me permanently block), I'm now falling back to what was once my Plan A: ~2.35 Constant Image Height (CIH) 130" screen (still from Monoprice), which leaves enough room above to do the in-wall center channel and still stay almost 24" off the slab. The actual screen height is only about 8" less than the 16x9 screen I'd planned, and it looks as though the width is a better match to the as-built wall. The Carada equivalent is almost twice as much as the Monoprice basic screen, and their very-nice remote control masking system would add another 10x (!!) ...so it looks as though I'll be doing some DIY engineering of a manual masking system. Before the baseboards go in, I'll also wire for a second center channel speaker below the screen.

    Another alternative is an AT screen, but I'd likely go DIY on that as well given the prices I've seen. (I don't currently see any AT screens for sale at Monoprice...correct me if I'm wrong.) My budget for the screen alone on this, since I've not yet purchased the projector and I'm simultaneously trying to save for LSiM 707s, is <$1K (preferably much less).
    Current polk speakers:
    Family room 5.1: TC265i R/L, VM10 Center, RC65i surrounds (couldn't match the TCs)
    Basement non-dedicated 7.1 HT: SDA-CRS+ R/L, 255c-LS Center, LSiFX surrounds, RC80i in-ceiling rear surround, plus Wharfedale 12" sub (some day I'll get around to building 15" F-20 sub).