Sound damping for tennis backboard

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We wish to construct a practice backboard and are worried about excess noise primarily off the back of the board.

We have 3/4" ply and 2X6 plates. We are trying to determine which would be more effective:

A party wall with 2X4 studs and ply on both sides
or
A constrained layer damping system using 2 layers of ply on the front and Green Glue for the damping.

I have some thoughts but would really like to hear yours.
 
Cal, where is the noise problem, with people on the court or elsewhere? If so, who and how loud is the thing now?

Also, a flat, vertical wall is not terribly useful as a practice backboard. A slight upward slope is more betterer... you have a tennis court??

_-_-bear (former pretty darn good tennis player)
 
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Hi, thanks for the answers. The board is for at my father's complex. It is the others that are concerned about possible noise, mostly out the rear of the board. He is hoping to have something that is as quiet as possible. Concrete is not an option unfortunately.

There is no back board in place, we want to make it right the first time.
 
I'd do a test or two.

Thinking build the board the way Geddes suggests making walls in a home. I think it is by using a semi flexible construction adhesive (careful, some harden over time) to hold two layers together. But I'd probably attach it backwards compared to a wall, affix the outer layer to the frame so that energy is not lost/absorbed by the backboard, just sound... so probably a thicker front ply and a thinner rear...

So maybe make a smallish (3ft) square frame with two versions, one with the rear damping layer and one without, do a drop test
or if someone can hit a target a hit with the ball test and see the relative rebound...

I think you have two sounds, one the drum sound the other the then transmitted sound from the rear.

The problem with putting a back on it is that if you stuff it, whatever is in there will harbor bugs and moisture...

As I said, it should be angled slightly up - you have to test for the best angle, otherwise most hits will go down and short. A few degrees...

Is this a permanent install or a removable one??

For permanent the blue board (cement board) used for showers *might* work, possibly with a thin parge of stucco/cement and a coat of something like UGL waterblock paint (a portland containing pigmented mixture) for good looks (add pigment for color).

It's heavy enough so that it may not have significant noise... and depending on the spacing of the rear frame the drum freq will be changed...

Also, it probably makes sense to use a flexible adhesive between whatever you use and the frame for added damping...

_-_-bear

I assume they have $$ so you could stand up a few 4x8 test sections of different construction and see what they do... :D
 
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Thinking build the board the way Geddes suggests making walls in a home. I think it is by using a semi flexible construction adhesive
That would be the Green Glue in post 1.
so probably a thicker front ply and a thinner rear...
We have free 3/4" plywood that is used as reusable form board and has a nice smooth, waterproof surface and edges. It cost about 100 CAD per sheet so I think we will try and use it.
I think you have two sounds, one the drum sound the other the then transmitted sound from the rear.
Yes, so which is more effective, the layered damping or the party wall, i wonder?
The problem with putting a back on it is that if you stuff it, whatever is in there will harbor bugs and moisture...
That's ok, that right in my line of work so I am sure I can come up with some fancy dancy solution.
Is this a permanent install or a removable one??
Permanent
For permanent the blue board (cement board)
Now there's something I hadn't though of. We can build it as a simple board and if that is too noisy for the neighbours (who's units are no closer than 100 ft from this board) then we can glue a layer of cement board to it with Green Glue.

You're a genius Bear!
 
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Hi Enzo, I seem to skip over your post and answer Bear's

Noise that would go where?
From the tennis court toward the condominiums
Into the house?
Or if anyone is on their patios/decks
Into the neighbor's lives?
Yes.
So radiated or conducted, basically?
Radiated only, no conduction.
Indoors/outdoors?
Outdoors, Approximately 35m/100 ft. distance to the nearest condo.
Poured concrete wall instead of wood?
Not an option or I would build them a cinder block wall. :)
 
A quiet & better tennis backboard

I'd like to suggest a quick look at The TFI Tennis Buddy Backboard. I invented this portable, duel-sided backboard and it is filled with a solid, sound-absorbing resin and fiberglass ribs which make it akin to the sound of a concrete wall. However, it has so many other tennis skills advantages that, if not apparent then please contact me at BeautifulDay@woh.rr.com
Bernie
 
I'd vote for the cement board with a parge coat.

Outer surface. Likely to be sonically almost dead at LF, which is
where the sound problem will come from, the higher freqs will naturally attenuate over distance.

If you need more then put a flex/damping layer on back... should make it perfectly quiet more or less.

The advantage of the cement board is that it is environment proof and it does not flex much, making it a very good backboard, and a bad drum.

Try a single 4x8 section? Cheap enough.

_-_-bear
 
How about this. Construct your wall with 2x4' studs, your plywood on the inside. You don't need 3/4" plywood, 5/8" is plenty strong enough. You will need to paint the plywood with a good quality paint to prevent warpage. And put a piece of galvanized steel roofing apex over the top to keep rain out. Now on the outside use at least 1/2" drywall. Drywall is an excellent sound deadener. 5/8" would be much better, that's what is used in hospitals and other buildings where sound isolation is important. You will have to waterproof the drywall and that's where your main problem will be. Just wrapping it with plastic wrap won't last long in the sun so you'd have to come up with something else for that. But the drywall would be cheaper than concrete and more effective at reducing sound. Two layers of 1/2" might be best, easier to handle and thicker than 5/8". Maybe a couple of coats of enamel paint would work to seal it. Seal the edges with 100% silicone caulking. Yeah.
 
Hi Sharpy, Thanks for the input.
I like the idea behind drywall but I can see some problems here. One is that you are in Florida and I am in Vancouver. :)
Even Aqua-Board would be out of the question. We already have the 2X6 red cedar for the frame and a special kind of reusable plywood used for forming. Instead of the party wall we have decided to assemble a standard stick frame wall, 12" OC and multiple purlin battens to reduce the panel size and try it out. Yes, we will be using a bit of peel and stick roofing (or EPDM) over the top and capping with sheet metal. Everything will be cut, drilled, countersunk and painted before assembly with EG screws and sub-floor glue. I'm not new at this sort of thing so I won't be doing them any favours with the bottom line, I have a penchant for making things last. :)
We have but one (or maybe two?) chances to get this right so...

Anyways cheers, if I were in your neck of the woods...
 
I was looking at this older thread:

Did you ever come up with a solution to this? I'm in the same boat as you were. Built a 3/4 oak plywood attached to 2x4s - leaned and attached to my shed and the sound is like a cannon going off when my son hits against it. Not sure my neighbors will are really thrilled with the noise.

I'm looking to try something to help and wondering if you found a solution that reduced the noise.

I was thinking similar - adding insulation inside the studs and adding another piece of plywood on the rear.

thanks for any help / response.
 
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