Sub-woofer on ceiling / In-Ceiling Subwoofer

[elangoas]

Hi elangoas..

I have 4 yamaha IWC series in - ceiling speakers mounted directly on the false ceiling. When I carry out the speaker calibration, when audyssey plays those tones through these speakers, I can sense the false ceiling flexing and vibrating a bit. So mounting a sub might actually contribute to more vibration.

Thank you.. Is your false ceiling made of gypsum board? and thickness of the material if you are aware of it..

Maybe better to build a thick and rigid Plywood box onto the ceiling and then Mount the driver to this box. The false ceiling when built can be lowered to a level flush with the driver for that seamless look. Will not be a infinite baffled design, but might just work.

Good one.. Mounting them in independent locations would be the easiest way..

I had seen some posts / pictures on AVS & other places where they have used the entire room as a sealed enclosure (or) part of their house above their floor as sealed enclosure.. They have used 2 drivers in one place (manifold) as they decouple vibration and NOT transmit to the ceiling.. In a similar fashion, thought why not use entire false ceiling (plywood) as sealed enclosure with manifold kind.. With plywood, i believe we can increase the thickness 12mm/18mm unlike gypsum board which are thin and not as strong as plywood..

What am not clear is even after using 2 drivers in a location, would it still transfer vibrations to the plywood ceiling..

And the Plywood box might also prevent the bass seeping into the floor above yours. Just my 2 cents

I live on the 2nd floor and the floor above is open terrace..So shouldn't be a problem..

 

[newlash09]

Hi again elangoas.. Thanks for the detailed reply. I have a normal desi style falsely ceiling with gypsum boards and pop covering on top. I didn't measure the board thickness but I think it was 8 mm. But when I mounted my in-ceiling speakers, the entire ceiling was flexing like a sponge board. I should have asked the designer to Mount extra bracing with aluminium frames at the planned speaker locations. But as usual, I always learn after burning my fingers first

But once we are playing music or movies, there is no sense of the false ceiling flexing. This could also be due to audyssey sending a full range signal to the speaker during calibration. And after calibration audyssey showed their crossover as 40hz, and I increased it to 80hz, to avoid my false ceiling collapsing. So at 80hz there is no sign of flex. It could also be that my speakers are now not close to the resonating frequency of the ceiling.

As regards your query regarding mounting 2 subs in a big plywood ceiling, even I don't know what to expect. My worry would be more about the bass driver reaching the resonating frequency of the Plywood ceiling at some point and inducing vibrations in the entire structure. A small plywood box can be braced rigidly to control one driver, but bracing an entire 13x11 ft plywood ceiling will be both difficult and very expensive in my opinion.

 

[vj_box]

Just being curious - are ceiling subwoofers part of an actual Dolby Atmos setup in Cinemas? I am not referring to home theatres.
I guess IMAX has top mounted subwoofers too for added effects?

 

[elangoas]

A small plywood box can be braced rigidly to control one driver, but bracing an entire 13x11 ft plywood ceiling will be both difficult and very expensive in my opinion.

Right.. Bracing the entire ceiling might not be feasible..

So, single box should be more rigid which should contain vibrations..

are ceiling subwoofers part of an actual Dolby Atmos setup in Cinemas?

No idea on this.. But don't think that would be the case..

I guess IMAX has top mounted subwoofers too for added effects?

I think subwoofers used for cinema halls must be much larger driver than that used for home's.. Just wondering how did they manage to do it on ceiling..

 

[vj_box]

Right.. Bracing the entire ceiling might not be feasible..

So, single box should be more rigid which should contain vibrations..



No idea on this.. But don't think that would be the case..



I think subwoofers used for cinema halls must be much larger driver than that used for home's.. Just wondering how did they manage to do it on ceiling..

Yeah I imagine. So I watched Jurrasic world last night at Satyam - Seasons screen. It’s a Dolby Atmos screen and had a couple of large dual subwoofers mounted on either sides of the Theater. I guess they are part of the setup.

 

[ItsMe]

Right.. Bracing the entire ceiling might not be feasible..

So, single box should be more rigid which should contain vibrations..



No idea on this.. But don't think that would be the case..



I think subwoofers used for cinema halls must be much larger driver than that used for home's.. Just wondering how did they manage to do it on ceiling..

I have visited a theater sometime back while they were revamping, and found that the subs were placed behind the screen on side walls and on the back wall.... I dont remember seeing any provision for sub in the ceiling...

 

[elangoas]

Came across bass tube subwoofers, which are used for car audio.. Cylindrical ones.. These seem to be made of MDF, have speaker level inputs. Guess, these can be directly connected to stereo power amplifier for home..

Just a weird thought.. What if we can make a custom build (sealed) one like this for a specific sub-woofer driver & may be suspend it from ceiling.. May be this will help cancel height modes too..

Hi Mods, @jls001 , @Nikhil request you to please change the thread title from In-Ceiling Subwoofer.. to Sub-woofer on ceiling / In-Ceiling Subwoofer..

 

[elangoas]

The below image is my room layout & speaker positioning..

At present i have dual identical ported subs, in the front corners of my room (not the ideal location)..

After bit of reading articles and posts by other members, the ideal location for dual subs seem to be 1/4th & 3/4 of room width and located centrally length wise..I did try positioning my present subs in the ideal room location and it did seem to have smoother response than being at room corners..

Practically, am unable to have them at the ideal locations in the room as it is a living room and a walk way to other connecting rooms..

Had a thought.. I have a stereo power amplifier being unused.. What if, i make DIY dual passive sealed subs (easier for DIY), power it with unused stereo power amplifier and put the DIY compact passive sealed subs at the ideal location, mounted / suspended from ceiling (A small distance from ceiling)..

I think, a sub's response should be better if isolated from room boundaries..

What could be the possible downside here?..

Note : I have no experience with manual EQ, just have to rely on Audyssey XT32 on my AVR to do the rest..

 

[newlash09]

Hi elangoas...

Iam no expert . But I usually see that subs have specially designed high power amps with very high damping factor, to precisely control that big driver. So normal stereo amps might not be ideal to drive big bass drivers. I could be completely wrong as well

I have been searching for a sub for quiet sometime, and found a wall / ceiling mounted sub from a audio company in Hyderabad. Though it is proving to be very expensive and comes with a external 500w class a+ax amp. My room is 17x11 feet. I sit facing the shorter length of the room. So will mounting this monster sub above the TV be suitable, or should I mount it in the centre on the room in the ceiling where I have a thick wooden panelling. Thanks

 

[elangoas]

Hi elangoas...

Iam no expert . But I usually see that subs have specially designed high power amps with very high damping factor, to precisely control that big driver. So normal stereo amps might not be ideal to drive big bass drivers. I could be completely wrong as well

Thank you.. Got it.. The idea is to experiment with unused stereo ampifier and if the results are good, then will consider getting a dedicated amplifier..

I have been searching for a sub for quiet sometime, and found a wall / ceiling mounted sub from a audio company in Hyderabad. Though it is proving to be very expensive and comes with a external 500w class a+ax amp. My room is 17x11 feet. I sit facing the shorter length of the room. So will mounting this monster sub above the TV be suitable, or should I mount it in the centre on the room in the ceiling where I have a thick wooden panelling. Thanks

Ok.. You have a similar listening position as mine, but more wider (17 feet)..

Download, the room mode calculator excel file from this link - https://www.harman.com/room-mode-calculator

If you key in your room dimension there, modes pop-up in the excel file..

One of the FM said that subwoofer is a device that radiates bass in all directions like a sphere, then it should ideally be in the center of the room (logically for a single sub)..

You would have also known (from articles) that two subs do a better job in a room.. So divide the room in to two equal halves and place each sub in the center of each half.. Which is the same as placing the subs at 1/4th (4.25 feet) from left wall, 3/4 (4.25 feet) from right wall & center of room length would be more beneficial.. Same as shown in above image..

Since, the subs would be externally powered, then it is same as a passive speaker.. If you have challenges positioning them on the floor, then you may consider positioning them on ceiling using DIY ideas..( I have not done this, but it should work)..

Could you share a link for the sub & the amplifier?..

 

[iiirshad]

had this sub. which you can mount on wall. by B&O

 

[elangoas]

had this sub. which you can mount on wall. by B&O

Interesting.. Believe these are powered externally?..

 

[iiirshad]

its Active stereo Subwoofer. 2 Driver in it. 100 plus 100 watt. specialy Design for music purpose. very unik design. By BANG & Olufsen. Denmark.

 

[iiirshad]

my little baby. 800 wtt rms active sub. but u can not mount on wall or in ceiling. b&o made.

Beolab 2

 

[iiirshad]

beolab2

 

[elangoas]

my little baby. 800 wtt rms active sub. but u can not mount on wall or in ceiling. b&o made.

Beolab 2

Awesome.. These look lovely..

 

[iiirshad]

had 3 sub . beolab 2

 

[elangoas]

Recently, completed the dual DIY sealed dual subs and mounted them to ceiling..

Some pics of the build..

12 inch IWAI drivers

Used FM Ravindra Desai, sealed enclosure dimensions of 15 x 15 x 17 inches..

Driver mounted on the bottom of the enclosure

Powered by Sonodyne stereo power amplifier

Mounting to ceiling with swing chair hooks procured from local hardware shop..

The Open hooks goes into the ceiling, the rubber bush was pushed inside the closed hook on the enclosure and then suspended to the open hooks that are fixed to the ceiling.. Rubber bush should help decouple vibrations from sub to hooks..

Subs on ceiling

Hooked it up with Sonodyne power amplifier, sounds good.. Bass feels better than before (Taga subs were placed on floor and in front room corners)..

Since the subs were elevated, guess it has lost the boundary gain.. and i had to increase the level in Denon AVR.. Sonodyne Stereo power amplifier doesn't have gain control.. The driver is at 7.5 feet above the floor (90 inches)..

Movies sound better with dual sealed subs.. Even a small movement in some scenes there is rumble on the subs..

Honestly, i have no idea of subwoofer freq response (or) at my listening position.. Will try to measure them & update by weekend.. Hoping it would be good..

 

[iiirshad]

like it

 

[elangoas]

Just an observation - after moving the subs to ceiling, feel the bass from the front L & R sound more prominent than before..