In-Ceiling Speakers, Suspended Ceiling. Doomed?
|
New member Username: AbillmannMadison, WI United States Post Number: 8 Registered: Jul-06 | My girlfriend works in a small physical therapy office and wants to put two speakers in the suspended ceiling of the therapy room. The ceiling is the usual 2' x 2' tile, with an aluminum grid. Floor-standing speakers, bookshelf speakers or wall-mounted speakers aren't options. So... my question is... if we put typical in-wall speakers up there, with no enclosure whatsoever, what's going to happen to the sound quality? I've done in-walls before, always between studs, and sometimes filled with insulation...they've sounded quite good. But what will happen with in-wall speakers in a suspended ceiling? Any thoughts or insights GREATLY appreciated. |
|
Platinum Member Username: NuckPost Number: 11931 Registered: Dec-04 | If the load is distributed across several grids, then a full range speaker would be ok, used as an open baffle design. |
|
New member Username: AbillmannMadison, WI United States Post Number: 9 Registered: Jul-06 | I guess my main concern would be an almost total lack of bass response. I seriously doubt if a powered sub could be added anywhere. I have the feeling the speakers (full-range, 8" woofers, 1" tweeters) won't yield very much low end. Should I try to find a creative way to add a sub? I know the usual answer is "try it and see," but in this case, I doubt I'll have that luxury. |
|
Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 13444 Registered: May-04 | . I wouldn't expect great results from what you describe. If the tiles are not an acoustic tile, in other words rigid fiberglass, the ceiling tiles will leak air through the tile. If you are starting with rigid fiberglass, the tile will still leak air, just less than a pressed fiber tile would (rigid in this case means the tile will stand upright without additional support when leaning against a wall or placed in a frame, it does not imply rigid like a piece of plywood or MDF). Given you are dealing with 2'X2' tiles there is nothing there to really set up an infinite baffle system. The longest wavelength before you reach an air leak at the closest seam is only a bit over a foot away. If you assume you only require about a third to a quarter wave length to provide decent bass extension, that still has the bottom rolling off at about 100Hz and sounding rather thin at that point. That would be stretching it to say you'll be OK for background music. If you have rigid fiberglass tiles to work with and you want to seal all of the air leaks to create a larger baffle (which will make someone unhappy when they need to lift or replace a tile), then you will achieve better bass extension. I still wouldn't expect much beyond acceptable sound since the tiles aren't really all that rigid and will flex with the speaker's movement. Ceiling mount speakers work best when they are installed in a true ceiling which can form a more or less real infinite baffle. Even then an "infinite baffle" deprives the system of any back wave reinforcement which means the speaker requires more power to reach an acceptable volume level. Depending on your amplifier, this might not be a problem. Walk around a few shops and listen to the various speakers to judge what you might get with speakers installed in a drop ceiling. The weight of any decent in wall speaker will eventually cause the ceiling tile to sag unless you reinforce the tile. If you wanted to make a project out of this, you could do some work above the tiles and make a workable solution. Otherwise, I'd opt for another solution or go with small in wall/on wall speakers, reinforce the tile a bit to avoid sag and add a small subwoofer on the floor. Overall, the best solution might be a decent compact system on the side. . |
|
Platinum Member Username: NuckPost Number: 11934 Registered: Dec-04 | mmg's as on wall panels? |
|
Platinum Member Username: NuckPost Number: 11935 Registered: Dec-04 | With a sub mounted in the next room or closet? |
|
New member Username: AbillmannMadison, WI United States Post Number: 10 Registered: Jul-06 | OK, first -- thank you. You guys are unbelievably knowledgeable and thorough! Regarding the weight of the speakers: I'll reinforce the grid with extra support wire in the areas where the speakers are located. That won't be a problem. Regarding a possible powered subwoofer: Would using a sub placed inside a closet be worthwhile? I always thought that while omnidirectional, a sub still needs to be unobstructed. Or at least not enclosed. For the ceiling tile itself, what would be an ideal layer of "rigidity" above the ceiling tile? Thick plexiglass? Plywood? Would it matter as long as it's thick and rigid? |
|
Bronze Member Username: AbillmannMadison, WI United States Post Number: 11 Registered: Jul-06 | Nuck: MMG's? As in Magnepans? Dude! Two problems: 1. Only one of my six Powerball numbers matched last night. 2. We'd have to change the marketing materials of the clinic to "Physical Therapy for Completely Serious Audiophiles." (Love it though! I might need to intentionally break my ankle or something!) |
|
Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 13450 Registered: May-04 | . Some 1/2" ply cut to the 2'X2' size should be sufficient for the weight of most ceiling speakers. To build an "infinite baffle" all you need is something solid to block air leaks, cardboard or poster board is sufficient if it is completely sealed to its edges. If it isn't sealed or not the appropriate size, then you still have problems. If you get serious about this project roll out a few strips of R19 insulation over the "baffle" though this isn't truly needed if you've done the job correctly and sealed all the air leaks to about five feet out in each direction. The larger the baffle - to a point where no backwave can wrap around the baffle board - the deeper the bass extension. If you're using a subwoofer, figure out where the sub comes in and you only have to build the baffle a bit larger than the highest usable frequency the subwoofer will carry. http://www.audiogearreviews.com/tech/theory/system_design/system_design.asp Yeah, a subwoofer in a closed closet sounds like a subwoofer in a closed closet. . |
|
Bronze Member Username: Db_audiofileLa habra, Ca Usa Post Number: 78 Registered: Aug-07 | Andrew, You are asking a lot from a very limited list of options. I asume that this background music. I have installed this type of system many times. In Tiles, (2x2) weight is a critical issue. Also since the area above is open you will have to use CL3 Wire. It is solid and teflon insulated. This is a must for commerical buildings. Trust me, the fire marshall will make you remove it! I use Poineer car speakers. Not bad sound, light weight, and easy to install. Make sure that you use only 1 pair of apeakers. These are usually 4 ohm loads. Good Luck, Db |
|
Bronze Member Username: Db_audiofileLa habra, Ca Usa Post Number: 80 Registered: Aug-07 | Andrew, What ever you use to re-inforce must meet FIRE CODES. Do yourself a favor, DON'T GET CAUGHT! Db |
|
Bronze Member Username: AbillmannMadison, WI United States Post Number: 12 Registered: Jul-06 | CL3 wire - definitely. I was planning on that. For the reinforcement of the grid, I'm thinking I might go with some brittle, old birch. Wait, no. It would actually be the same suspension wire that's in use now. In terms of fire code, I'm sure it won't be a problem. But those are excellent points -- I certainly don't want it torn out. Bonus: The fire department is literally across the street, so maybe I'll check in with them before starting the job! |
|
Platinum Member Username: NuckPost Number: 11939 Registered: Dec-04 | You dont need to be neurotic as the speaker loads are minimal, and not in the building grid, thus exempt, unless you live in an omnipotent government snoop, over bearing, control obsessed commune of liberal pinko's. Or California. the IB for the ceiling is as JV described, and brittle baffle material will not help your cause. You can obtain some ply in size to add rigidity without too much weight. Bamboo might be available also. As far as the MMG's go, these are the bottom of the line, readily available model, and may serve you well without going up into the abyss. The closet sub is of a particular design as JV linked, and is simple and easy to accomplish. Car speakers are meant for a sealed area of the trunk of a car, and are horrid in free air, such as a ceiling area. Look into MMG's and read the links. The sub need not go to 30Hz, by your desires as described, and 50 is quite low for a confined area full of agitated individuals. I dont expect a lot of Rap going on there, or volumes of mass bass Orchestral for that matter. The sub as described will deliver nice bass from afar, up to a volume limit. If the place is to be used as a disco after hours, please disregard. Have fun! |
|
Silver Member Username: WattsssupBarrie, ON Canada Post Number: 301 Registered: Aug-06 | I love California! Don't mind me, carry on... |
|
Bronze Member Username: Db_audiofileLa habra, Ca Usa Post Number: 83 Registered: Aug-07 | Andrew, Light weight ceiling enclousures are very cheap! They do a great job. Subs are insane in this enviroment. Sorry Nuck, I disagree with you on this one. Good Luck Db |
|
Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 13453 Registered: May-04 | . Since fire codes might be an issue, consider this; use a few more ceiling tiles and cut them down to the height of the drop ceiling to actual ceiling distance minus just a bit to give yourself some working room. Construct a box from these pieces and back it with another ceiling tile so you have constructed a(n open front) box out of ceiling tiles. Use some construction adhesive to bond the pieces together. Stuff the box with some Kraft-faced fiberglass insulation to create an acoustic suspension system without air leaks. AS systems don't like air leaks so you'll have to do some good work to actually seal the enclosure well. If that sounds like a workable plan, figure the average 8" driver would prefer approximately a 1 1/2 to 1 3/4 cubic foot enclosure volume. The actual shape of the enclosure isn't that important in this application, just figure whatever dimensions will get you to roughly that 1 1/2 cubic foot enclosure. Don't overstuff the box with fiberglass as this will raise the bass extension too much. Start with the least amount of fiberglass you can deal with and add more as you listen. Remember to wear eye and nose protection and long sleeves and gloves when working with fiberglass. http://www.ask.com/bar?q=Cubic+Feet+in+a+Box&page=1&qsrc=6&ab=0&u=http%3A%2F%2Fw ww.installer.com%2Ftech%2Fboxsize.html Other alternatives would include; http://www.parts-express.com/pe/showdetl.cfm?Partnumber=241-938 http://www.parts-express.com/pe/showdetl.cfm?Partnumber=242-862 . |
|
Bronze Member Username: Db_audiofileLa habra, Ca Usa Post Number: 84 Registered: Aug-07 | andrew, Jan is right if you are going to that much trouble. Db |
|
Platinum Member Username: NuckPost Number: 11942 Registered: Dec-04 | nice! |
|
Bronze Member Username: AbillmannMadison, WI United States Post Number: 13 Registered: Jul-06 | Jan: You are incredible. I'm going to try it your way... build an insulated enclosure from additional tiles. I love the challenge in this! Thank you! |
|
Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 13455 Registered: May-04 | . If you want a challenge, try building this as a transmision line.  http://www.t-linespeakers.org/classics/index.html . |
|
Platinum Member Username: NuckPost Number: 11953 Registered: Dec-04 | Cruel, but funny at the same time. |
|
Platinum Member Username: NuckPost Number: 11954 Registered: Dec-04 | The Nautilis curl can be built into an end table. OK, a big one, but still... |
|
Bronze Member Username: AbillmannMadison, WI United States Post Number: 14 Registered: Jul-06 | Maybe I should just go straight for the Klipschorns.  |
|
Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 13456 Registered: May-04 | . They will definitely sag a ceiling tile. |
|
Platinum Member Username: Jan_b_vigneDallas, TX Post Number: 13457 Registered: May-04 | . "Yeah, a subwoofer in a closed closet sounds like a subwoofer in a closed closet." If you are considering a subwoofer, consider placing it in a closet or adjacent room with a vent facing into the room with the speakers. If you can do this in the building you are in, use a large grated air vent such as you might buy at Home Depot for use as an air return in a HVAC system. With this system a vent roughly 16"x16" (smaller if need be) would be the air passage between the inside of the closet with the sub facing and sitting close to this vent. The smallest dimension of the vent should be not much smaller than the diameter of the subwoofer's driver. For non-critical listening this system should work fine. . |
|
Platinum Member Username: NuckPost Number: 11957 Registered: Dec-04 | With MMG's on wall mounts, no ceiling work needed. |
Main Forums
Today's Posts- Home Audio Forum
- A/V Receivers Forum
- Amps Forum
- Cassette Forum
- CD Players Forum
- CD Recorders Forum
- DAC & Transports Forum
- DVD-Audio & SACD Forum
- Equalizers Forum
- Integrated Amps Forum
- iPod Docks Forum
- MiniDisc Forum
- Mini Systems Forum
- Digital Music Systems Forum
- Phono Forum
- Preamps Forum
- Speakers Forum
- Subwoofers Forum
- Tuners Forum
- Home Video Forum
- Home Theater Forum
- Car Audio Forum
- Accessories Forum
- All Forum Topics