Low-Noise Basketball Backboard
Low-Noise Basketball Backboard
(OP)
My kids love basketball and play in our cul-de-sac, but a neighbor has complained about the noise from the ball and backboard. I have found some low-noise foam-filled basketballs that bounce about like a real basketball, and now want to make a sound-dampening backboard that will produce very little noise. Any suggestions as to how to construct it?





RE: Low-Noise Basketball Backboard
RE: Low-Noise Basketball Backboard
TTFN
RE: Low-Noise Basketball Backboard
Make sure it is firmly attached to the pole or two poles. Then spray on automotve undercoating to the back of the backboard. If there is a space between the backboards then foam in between. The supporting pole(s) can also vibrate so you may want to use elastomeric mounts between the backboard and the pole(s). You may also want to add stiffeners to the backboard.
Regards
Dave
RE: Low-Noise Basketball Backboard
1. Cutting the backbard from laminate treated plywood.
2. Gluing a rubberized or composite sheet to the front of it that wraps around the edges.
3. Screwing it to a stiffening frame of treated 2"x2"s, tucking the sheet under the frame.
4. Spraying the back of it with an automotive underhood spray.
5. Mounting it to the pole with elastomeric mounts.
Any other ideas, please let me know. Once I build it, I will let you know how well it works and will post a picture when I am done.
RE: Low-Noise Basketball Backboard
Regards
Dave
RE: Low-Noise Basketball Backboard
RE: Low-Noise Basketball Backboard
Mike Halloran
Pembroke Pines, FL, USA
RE: Low-Noise Basketball Backboard
RE: Low-Noise Basketball Backboard
I'd suggest that what you need is a backboard that doesn't vibrate and hence won't radiate noise. A sheet of lead would be ideal, but might be hard to hold up, so I'd suggest this as an alternative: you can make the backboard from a sheet of "dB-Ply" plywood from Greenwood Forest Products (Portland, Or.) It is a plywood that incorporates a viscous damping layer.
Others have suggested foam or other materials sprayed to the backside of the backboard and while these will slightly reduce the noise, they are not as effective as you might wish.
What you want is a means of applying a constrained-layer damper to the backside of the backboard: one way of doing this would be to apply a layer of 3M trim cement or equivalent to the backside, and use it to mount a layer of sheetmetal or plywood. Then vibrations in the backboard are dissipated in trying to shear the adhesive.
Then you'll only have to deal with the kids' shouts when they score the winning basket...
RE: Low-Noise Basketball Backboard
3/16" ply
damping layer
5/8" ply
roughly
This will be far more effective than a sprayed-on layer of goop.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Low-Noise Basketball Backboard
RE: Low-Noise Basketball Backboard
Sharp thump? The "tunk" or slap the basketball makes itself when bounced on concrete?
Hollow ringing of the steel pole?
Once the pole is stiff and full of expanding foam, and
Damping and stiffness have been applied liberally to reduce the flexing and ringing of the backboard, (and perhaps noticeably influence the ball's rebound) but in the limit you're left with a rigid body motion, which makes a fine loudspeaker.
When all else is optimized Howzabout making backboard perforated with holes sized for the frequencies of interest. The purpose is partly to equalize the pressure front and rear. Mighty effective in making quiet belt guards, etc.
RE: Low-Noise Basketball Backboard
Another variable you might explore is the inflation pressure of the basketball.
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RE: Low-Noise Basketball Backboard
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Low-Noise Basketball Backboard