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Posted By: sbcgroup1 M80 WALL MOUNTS - 12/16/03 04:36 PM
I am setting up a home theatre with two M80's and a VP150 center in the front. I want to mount them all horizontally on the wall above my movie screen. I need help finding dedicated speaker mounts for the M80's. Right now I'm only finding TV wall mounts that could handle the job...

Any suggestions?

Thanks,

-sbc
Posted By: pmbuko Re: M80 WALL MOUNTS - 12/16/03 05:44 PM
You're kidding, right?
Posted By: MIKEY Re: M80 WALL MOUNTS - 12/16/03 05:50 PM
Hmmmmmmm, interesting.. Not enough room on the sides to hang the Eighties vertical ?
How much room between the top of the screen and the ceiling ? I'm thinking, three or four M22's.. One or two for center work, and the other two as wingers..
My thoughts: As this center channel is working the hardest most of the time, why not give it something bigger to work with ? If the theater room is wide enough, go with two 22's, toed 'out' a tad to give a nice spread..
I've said this before, if and when I do this again, I'm going with twenty twos all across the front.. With a couple subs (or a wall or ceiling mounted IB) what more could you want ? Save the 80's for the music room..

Posted By: snippy Re: M80 WALL MOUNTS - 12/16/03 08:42 PM
I am sure that two full metal brackets could hold up an M80. You shold buy two pairs of them from Axiom.
Posted By: spiffnme Re: M80 WALL MOUNTS - 12/16/03 08:54 PM
I'm not so sure I agree with Snippy on this one. That's an awful lot of weight.
Posted By: Ken.C Re: M80 WALL MOUNTS - 12/16/03 09:19 PM
Well, they do say that they hold up to 40 lbs each... and the M80s weigh 57 lbs. However, I don't know if you can sum that, and I don't know that I would trust it. I mean, the distance out from the wall alone would be a massive strain. The M80s are 15 inches deep, and not a bit of that would be supported. Well, maybe 1 or 2 inches. It'd scare the crap outta me.

I also kind of have to question the intent of the original poster in setting them up horizontally. I mean, the M80s are 40 inches tall (wide) and the VP150 is 29.5 inches wide. If you put them close enough together that they are touching, that's 110 inches! What kind of screen have you got that will cover all that? In addition, if they are touching, that's sort of creating one big huge mega wide speaker. You're not going to get very good separation out of that, and the imaging will be all funkay.

Anyway, that's my $1.95.
Posted By: rcvecc Re: M80 WALL MOUNTS - 12/16/03 10:04 PM
how about lag bolts in the ceiling with eyes on them-4 for each speaker-then use a thin cable or chain to suspend a shelf on and place the speakers on that....ron

Posted By: pmbuko Re: M80 WALL MOUNTS - 12/16/03 11:49 PM
I also doubt that two FMBs could do it. I have no doubt that the brackets themselves could take the strain, but the weak point here would be the MDF itself into which the brackets must be screwed. The M80s are 17" deep and 57 pounds each. Most of the weight is concentrated towards the front of the speaker, which means its center of gravity is pretty far away from the wall.

What this all boils down to is a tremendous force being placed on the mount points. Look at this diagram (that I actually drew to scale):



Gravity pulls straight down on the speaker at the center of gravity (the green crosshairs). Imagine the torque all the screws would have to endure in order to keep the speaker from tearing away.

While the FMBs are very sturdy, I doubt they were designed to hold that kind of load. Try holding a 40 pound weight close to your body, and then try holding it at arms length. Feel the difference?

Posted By: willscary Re: M80 WALL MOUNTS - 12/17/03 12:09 AM
I am impressed! Nice drawing! Gets the point across. The pulling force on the top of that bracket would be immense. Think of taking a piece of plywood 3'-0" X 3'-0" and screwing it to a wall with a bracket like that. Then have your 3rd grade son (8 yr old) sit on the side away from the wall. I don't think it would hold. Now, the M80s SHOULD be placed a few FEET from the wall, so make the plywood 3'-0" wide and about 4'-6" deep (away from the wall). Sit the same kid on the outside and his center of gravity would be about 3'-0" off the wall (just like the center of the M80s should be roughly positioned). Now will the bracket hold, or will it rip the screws (lag bolts?) out of the studs?
Posted By: Ken.C Re: M80 WALL MOUNTS - 12/17/03 12:31 AM
Of course, a question would be...
If you mounted the M80s vertially with 2 (or more) FMBs, would it improve things at all? You'd still have the center of gravity far away from the wall, but it could be supported by at least 2 different things..

Actually, all in all, I don't think the FMBs are suited to this project except for the VP150.
Posted By: pmbuko Re: M80 WALL MOUNTS - 12/17/03 12:42 AM
An M80 mounted vertically with two FMBs would work much better, actually. Two horizontally mounted brackets do little to counter the "rotational potential" of the M80. Two brackets mounted vertically would do a very good job at countering that potential. With the vertical orientation, you just have to worry about the shear stregth of the mount points, which I imagine is pretty high.
Posted By: Ken.C Re: M80 WALL MOUNTS - 12/17/03 12:43 AM
Even in the M80's MDF? I dunno.
Posted By: pmbuko Re: M80 WALL MOUNTS - 12/17/03 12:45 AM
Put a screw into a piece of cardboard (arguably much weaker than MDF). Not try pulling the screw horizontally through the cardboard. That's the kind of shear force I'm talking about.
Posted By: Ken.C Re: M80 WALL MOUNTS - 12/17/03 12:49 AM
I'd still be a little worried about rotation from the top, although I suppose you could put the mounts at top and bottom and be pretty free and clear.
Posted By: Haoleb Re: M80 WALL MOUNTS - 12/17/03 01:01 AM
In my opinion buying a speaker like the M80 and doing this wall mountin is kindof defeating the purpose of buying those speakers...

But if you insist you could do a drawbridge type setup that would hole em up easy. Just make sure your screwing into the studs with enough screws and long enough and stuff. but i still thing it sounds like a bad idea.
Posted By: real80sman Re: M80 WALL MOUNTS - 12/17/03 01:52 AM
I agree. Not a very good idea. With the two ports on the back, they NEED breathing room. The closest I can get mine to the back wall is 11 inches. (before they get boomy) I thought I read somewhere that the ideal is more like 24 inches off the back wall.
Posted By: Type_E Re: M80 WALL MOUNTS - 12/17/03 04:49 AM
I laughed immediately when I see the starter post.
Posted By: FordPrefect Re: M80 WALL MOUNTS - 12/17/03 12:01 PM
first I had to check to see if it was April 1st.

Bad idea, I think turning the M80's horizontal and wall mounting them would degrade the sound. The best alternative if you wish to have a front horizontal setup might be to go with 3 VP150's.
Posted By: Wid Re: M80 WALL MOUNTS - 12/17/03 03:35 PM
I do'nt think you understand about how a ported speaker works.Saying that I believe this is a really bad idea.My M80's are about 2 feet from the rear wall and sound great.Anything to close to the wall would not be of any benifit to the sound you get from a ported speaker.
Posted By: snippy Re: M80 WALL MOUNTS - 12/17/03 06:15 PM
I suggested the FMB because I thought he was going to try to mount them from the cieling. That would be kind of scary, though.
Posted By: pmbuko Re: M80 WALL MOUNTS - 12/18/03 12:50 AM
wid,

Once you get further than a few inches away from the wall. the port has nothing to do with any boominess you might hear. Even sealed design speakers placed too close to room boundaries won't sound their best.
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