[VonHess]

DIY remodeling my living room and my ceiling is newly primed and ready to be finished.  I am considering a few different options for the ceiling and wanted to see if you guys might have some ideas that I hadnt thought of that would be good for acoustics.  I know that I have an issue with reflections from the ceiling.  The speakers I have are designed to tilt back a bit (Spatial M2 Turbos).  When they are tilted back the sound is sort of echo-y for lack of a better word.  When I stand them straight up much of this goes away.  My ceiling is only 8ft so I dont want anything too thick that would make the ceiling even lower.  What I am considering so far:

1. paint- obviously the simplest and easiest  but does nothing for acoustics
2. grasscloth wallpaper- fits into my mid mod style I'm going with and has some substance that I would think would reduce reflections.  The downside is that wallpaper, especially on the ceiling, is a real pain in the a** to install.
3.Burlap- cheaper than grasscloth but has a similar look and since it's actual cloth probably a bit better for acoustics.  Probably as or more difficult installation than grasscloth.

thanks in advance for your help

[BobRex]

If you are thinking about just gluing up anything (burlap, velvet, grasscloth,...) it may look good, but you won't get any acoustic benefit.  The underlying  (overlying?) drywall will still be reflective.  You need something with a substantial thickness, or at least some separation from the hard surface.  Ideally a few strategically placed acoustic panels, or maybe some slatted panels (these would change the angle of reflection, and if designed properly reflect most of the energy back towards the front end of the room) are your best bet.  You could also determine the reflection point and tack a few pillows at those points.

[Hipper]

As Bob says, you don't have to treat the whole ceiling, just the bits that reflect the sound to you.

The mirror test or some simple drawings should determine where the reflections occur. Measure on the floor the distance between one of your speakers' drivers and your ears, halve that and imagine a vertical line straight up to the ceiling from that point (when you tilt your speakers, add the horizontal distance the tweeter moves before halving the distance). That is the area you will get reflections from your speaker. Same of course for the other one.

Now comes the difficult bit. You need to experiment with something (like a pillow) stuck to the ceiling to see if it really does have some impact on the sound. You could use a long piece of wood to jam the pillow up there.

If it does change the sound a bit for the better you should get (or make) some panels to attach to the ceiling. Companies like GIK or RealTraps will have ready made systems and offer good advice:

http://gikacoustics.co.uk/product/gik-acoustics-242-acoustic-panel/

http://gikacoustics.co.uk/product/acoustic-panel-ceiling-cloud-mounting-brackets/

[VonHess]

Hmmm, hadnt thought of velvet.  That might give it that loungy feel.  So if I can determine the point(s) of reflection a slatted panel could do the trick?  I like the idea of the slatted panel ( I am assuming similar to the picture here but lets say for example a 4 by 8 panel hanging a few inches off the ceiling).  it looks like a popular mid-mod slatted bench design and would fit perfectly.  Also, fairly easy to build.  I knew you guys would have some great ideas!

[BobRex]

You've got the right idea, but the slats should be further apart.  Both examples have too much reflective surface to be effective.  Use narrow slats (like the table) spaced between 2 and 3 inches apart.  Depth is secondary, but you need to have a greater percentage of open space to hard surface. 

Another trick is to just build a drywall wedge (say a 2x6 standing on edge, with drywall creating the wedge.)  The wedge could be any size, all you really want to do is re-direct the reflective path away from the listening position. 

[Mike-48]

You could use 2" 2D binary diffusers, like the RPG BAD panels or the GIK Alpha series. ASC also makes similar and will supply them with magnetic mounting.  Any of the vendors will help with placement for best effectiveness.

You are definitely on the right track, killing those ceiling reflections, IMO.  Sounds like a great project ... I hope it turns out spectacular for you.

[JLM]

Sorry but to offer a wide frequency band of diffusion the slats cannot be uniform in width/depth.  Diffusion depends on physical size to be effective (8 inch deep diffusion panels can only be effective down to roughly 1,100 Hz) and must be non-absorptive to be effective (no foam or thin plastic need apply).   Here's the best DIY recipe I've found for diffusors (but they do weigh 23# per 18 inch square):

http://www.pmerecords.com/Diffusor.cfm

But first measure your room with your gear and from the planned listening spot to know for sure what the problem is (and at what frequency).   Placement of treatments at first reflection points makes sense if the frequencies involved are above roughly 130 Hz. 

Note that most folks go absorption versus diffusion (but do it wrong, looking for effective looking material without obtaining absorption vs. frequency data).  High density fiberglass (Owens Corning 703, like GIK uses) is about the best you can do.  They build their panels with wire and wood frames surrounding the fiberglass to stretch the decorative fabric over and mount them floating down from the ceiling (see their website from here at Audio Circle).

Note also that there is almost as much snake oil in room treatments as various audio wire.   

[EdRo]

Doesn't anyone do the classic '70s basement ceiling treatment anymore? Who remembers this? Old shag carpeting stapled to the 2x12s?

[syzygy]

Ceilings, nothing more than ceilings.......

[EdRo]

Trying to forget my...ceilings of love!!!

[JLM]

Doesn't anyone do the classic '70s basement ceiling treatment anymore? Who remembers this? Old shag carpeting stapled to the 2x12s?

How does shag carpet measure for acoustic absorption (at a wide range of frequencies)?

What's the flame spread rating for carpet applied to the ceiling?  Realize that heat rises so the carpet would be the first thing to burst into flames and fall on top of occupants.

How would you clean ceiling mounted carpet?

The last time I saw ceiling mounted shag carpet was above a hot tub and all I could think about was mold growing overhead.   

[macrojack]

If you have floor joists overhead, perhaps it would be possible to spray in some closed cell foam insulation between them to deaden sound from above and provide a foundation for creation of your own original diffusor system. I'm imagining about 2 inches of the foam and a carefully calculated and designed diffusion pattern assembled between (and including) the joists. I do not know what I'm talking about so this suggestion has to be viewed as nothing more than a vaguely formed vision but perhaps and engineer like JLM or some of our in house room treatment guys can comment of this with a straight face.
If there are utility protrusions jutting down from the flooring between the joists, I would think that you could avoid spraying them in by boxing them and packing with a removable sound deadening packing and covering with an inset acoustic panel covered by the same material that you use for the ceiling covering. Remember that it must be acoustically transparent covering so that the diffuser pattern can do its magic.
Is this nonsense?

[JLM]

Macrojack brings up a good point.  Most ceilings can benefit from isolation for sound transmission from/to above as well as treatment for sound generated from within the room.  The best isolation is to create physical disconnect between the structure above and a relatively high mass/rigid ceiling.  I recommend attaching gauge metal Z-channels to the underside of the joists and attaching drywall to the channels, adding blown or batt insulation above.  And avoid electrical boxes, light fixtures (especially recessed cans) in the ceiling unless you box them in completely with drywall.  (Believe me, just because a fixture is rated to be air tight or in contact with insulation doesn't mean it's sound proof.)

For treatment the original post mentions wallpaper or burlap on the ceiling.  Neither would be effective or good ideas.  Neither have a fire rating for use on ceilings (as heat rises would be the first thing to burn and drop onto occupants.  Burlap would collect all sorts of small vermin and be impossible to clean.  Always beware of using building materials for unintended purposes.

[brj]

You could use the Owens Corning QuietZone SOLSERENE Fabric Ceiling System create a seamless surface appearance, but then apply whatever acoustic treatment behind it that you want, especially if you take down the current ceiling drywall first and can thus use the entire depth of the joist cavity for treatment.

[rollo]

You could use the Owens Corning QuietZone SOLSERENE Fabric Ceiling System create a seamless surface appearance, but then apply whatever acoustic treatment behind it that you want, especially if you take down the current ceiling drywall first and can thus use the entire depth of the joist cavity for treatment.

   Kinda what I'm doing now. Removed most of the concealed spline acoustical clg. tiles. That exposed the rafters supporting floor above. The joists have wood cross bracing every 18". Since it sounds like a 10ft clg. much more open than I ever thought possible.
   Yes sound does transmit to first floor more. I told my Wife to buy carpeting.  . May try some treatment in between joists and that product appears to be right, thanks.


charles

[Mike-48]

I think you will find that mechanical transmission of sound between floors won't be reduced much by any low-mass products, such as foam or fiberglass. Fiberglass will, of course, improve the acoustics of the space below, if it's installed well and acoustically exposed to that space. To really reduce sound transmission between floors, the best method is, as other posters said, some kind of resilient mounting of the ceiling below. However, that's relatively tricky and expensive to install and will eat up a few inches of headroom. 

Anything with mass will help for most frequencies. That would be, e.g., a double layer of gypsum or QuietRock in the ceiling. The conundrum is that those measures will increase, not decrease, acoustic reflections in the space below. If sound transmission between floors is the main goal, IMO you're better off sealing the ceiling well with massy materials, then mounting some kind of acoustic treatment on it.

I'm not an expert, but those are my observations and what acoustics people have told me.

HTH

[VonHess]

Alot of good info.  thanks guys.  I have recently put together a diagram of the room and its contents.  It is approximately 22.5’ x 12’ with 8’ ceiling.  The space above is empty attic space, no rooms or floors.  I believe the ceiling is insulated with whatever pink stuff they had 40 years ago.  I’ve been looking at Poly diffusers lately.  Anything I do will be diy and It looks like poly diffusers would be cheaper and a bit easier than the absorption panels since I can build them with materials I already have on hand. I was thinking about hanging a couple of poly diffusers between the lights and maybe right over the couch on the rear wall.   Eventually I probably will build a few absorption panels just to experiment with them. 

[rollo]

  My advice if turning into a dedicated room use the short wall for main speakers. You have a good rectangle to work with.



charles

[VonHess]

  My advice if turning into a dedicated room use the short wall for main speakers. You have a good rectangle to work with.



charles

I have considered that but with the windows in the middle of each of the short walls I couldnt mount the TV and if I put it on the console it would block the window.  I have also thought about an asymetrical set up but I really havent come up with anything that works.  The lower right corner is the entryway, the lower left corner would have a reflection from 2 windows on the TV screen.  The other 2 corners might work if I covered the short wall window with a blackout curtain.  I also just prefer the current setup for aesthetics so rearranging the room for a shortwall set up would be last on the list.

[JLM]

OK, scratch the concerns about ceiling isolation.

But also recommend turning the whole room setup 90 degrees (dipole speakers needs lots of space behind them to properly function) and give up the use of that window.  But if you keep it this way, lose the coffee table (which unnaturally reflects sound) and move the couch away from the back wall (where bass booms/muddies).  Then measure the room (define the problem before trying to solve it). 

Can you provide a link to the diffusers you have in mind?  Again most diffusers only function down to around 1,000 Hz and need significant distance from the listening position to be effective.  And most absorption materials are useless or only effective for midrange/treble frequencies.