What is a good material to use on the front of a speaker baffle to reduce reflections? I was thinking cork would be a cheap thing, but other's may look better.
ideas?
ideas?
Hi Brad,
I've always used 1/4", medium weight, closed cell foam rubber. It's easy to work with, easy to attach, and readily available (in urban areas). It does a good job above about 1kHz.
Heavy felt (1/4") would be better, but it's a bit tougher to work with and very difficult to find. You could dye it to meet you esthetic requirements and I would expect it to damp well down to possibly 500Hz or so.
Rodd Yamashita
I've always used 1/4", medium weight, closed cell foam rubber. It's easy to work with, easy to attach, and readily available (in urban areas). It does a good job above about 1kHz.
Heavy felt (1/4") would be better, but it's a bit tougher to work with and very difficult to find. You could dye it to meet you esthetic requirements and I would expect it to damp well down to possibly 500Hz or so.
Rodd Yamashita
i have use open cell foam but since we get it only in white here i cover it with a black cotton cloth. the cotton cloth is not very thick very thin in fact aslmost tranlucent but it covers the foam well.
i have alos used felt but sincethe colour i got cheap was red i had it dyed. once could always srpay paint it.
i have alos used felt but sincethe colour i got cheap was red i had it dyed. once could always srpay paint it.
Felt is the classic. For an all-out design, layers of different thickness and density can provide hours of experimental fun.
If you're going to use foam rubber or plastic, open cell is much more effective. Again, a multilayer system can be quite effective; one set of speakers I built used three densities, with 8 pcf at the bottom, going to 6 pcf, and 4 pcf at the surface.
If you're going to use foam rubber or plastic, open cell is much more effective. Again, a multilayer system can be quite effective; one set of speakers I built used three densities, with 8 pcf at the bottom, going to 6 pcf, and 4 pcf at the surface.
I have used cork several occasions when I simply didn’t want to make router templates for recessing odd shaped driver frames. Cork sheet is readily available, comes in a variety of gauges and is very easy to cut.
If you are careful, the driver can be used as a template for cutting the cork. If the cut is tight enough to the frame edge (cork in sheet form is somewhat elastic), the cork will make a very snug and flush fit with the driver.
Unfortunately, thicker cork sheet does not bend easily. If you want to follow a baffle edge radius, make sure the radius is sufficiently large. I have not tried to trim it with a router, but I suspect that unless the bit was new routing it may tear it up.
I got the idea to use cork as a baffle veneer from looking at one of Be Yamamura’s loudspeakers at CES a number of years ago. Yamamura claims that cork sounds better than other materials, because it is natural and inherently well damped. While I have no specific insight into that claim, I did find the the finished speaker I built did sound very good, but really can’t say how much, if any, cork contributed to the overall sound.
Cork does look a little like particle board, but has a much nicer color. I have found that if it is applied and detailed correctly, it can look rather elegant.
If you are careful, the driver can be used as a template for cutting the cork. If the cut is tight enough to the frame edge (cork in sheet form is somewhat elastic), the cork will make a very snug and flush fit with the driver.
Unfortunately, thicker cork sheet does not bend easily. If you want to follow a baffle edge radius, make sure the radius is sufficiently large. I have not tried to trim it with a router, but I suspect that unless the bit was new routing it may tear it up.
I got the idea to use cork as a baffle veneer from looking at one of Be Yamamura’s loudspeakers at CES a number of years ago. Yamamura claims that cork sounds better than other materials, because it is natural and inherently well damped. While I have no specific insight into that claim, I did find the the finished speaker I built did sound very good, but really can’t say how much, if any, cork contributed to the overall sound.
Cork does look a little like particle board, but has a much nicer color. I have found that if it is applied and detailed correctly, it can look rather elegant.
NO BAFFLING.
Hello,
If you really want to cancel all frontpanel baffling:
Design for dedicated housing of you units a la B&W Nautilus.
If that's not feasable stick a sorbothane sheet on the frontpanel making sure you only leave the membrane/piston unimpeded.
This elastomer was used by the military to camouflage aircraft and submarine from radar/sonar signals.
Doing so will give a a near perfect point source.
It can also be put to good effect on the inside of the speakercabinet where it will effectively cancel resonance especially when used asymmetrically.(which I always do regardless of damping material)
My
Hello,
If you really want to cancel all frontpanel baffling:
Design for dedicated housing of you units a la B&W Nautilus.
If that's not feasable stick a sorbothane sheet on the frontpanel making sure you only leave the membrane/piston unimpeded.
This elastomer was used by the military to camouflage aircraft and submarine from radar/sonar signals.
Doing so will give a a near perfect point source.
It can also be put to good effect on the inside of the speakercabinet where it will effectively cancel resonance especially when used asymmetrically.(which I always do regardless of damping material)
My
roddyama said:
Felt works well. The sample in the picture was salvaged from a set of 20 year old Marsland speakers.
I figure that if i stiffen the backside with glue i can use it for a grill frame.
I also have all the raw material to make my own felt and was going to experiment with moulding it.
dave
Rodd, heavy felt is easy to find. Good ol' McMaster-Carr comes through again.
BTW, Frank, I seriously doubt that Sorbothane has any use against radar signals. You might check out The RCSR Handbook for materials that do.
BTW, Frank, I seriously doubt that Sorbothane has any use against radar signals. You might check out The RCSR Handbook for materials that do.
Sy,
I don't know why, but I never thought to look in the Mac-Car catalog for felt, I should have known.
There's a foam rubber store 2 miles from me. They carry anything from neoprene to bass foam rubber you can almost see through.
Rodd Yamashita
I don't know why, but I never thought to look in the Mac-Car catalog for felt, I should have known.
There's a foam rubber store 2 miles from me. They carry anything from neoprene to bass foam rubber you can almost see through.
Rodd Yamashita
Over the past several jobs I've had, I learned that if McMaster-Carr doesn't have it, you don't need it! The catalog is a terrific design engineering reference, too. I' m continually amazed that they can get stuff to me so fast.
Sy,
I’ve actually had a lot of experience with McMaster-Carr at previous jobs. Although at home, I seem to have a mental block against them. I think their always fast delivery goes against my tendency toward procrastination.
Rodd Yamashita
I’ve actually had a lot of experience with McMaster-Carr at previous jobs. Although at home, I seem to have a mental block against them. I think their always fast delivery goes against my tendency toward procrastination.
Rodd Yamashita
I use carpet, makes a huge difference and I put a slight bulge on the corner so as to get rid off the 90 degree angle. In the pic posted before hand, why is it cut in a star fashion on the outer-edge?
Bose(o) said:
Cut into an odd pointed star with bevels (and prime too). The bit over the surround tends to kill some resonances, and the star decreases any resonance modes across the cutout.
dave
navin said:
Stiffen the back -- a couple coats of PVA glue, maybe a thin piece of cardboard (dead record sleeve) -- and cover it with the same stuff you use to cover your (ugly?) white foam. Same end result cosmetically. You could also cut the star in the foam.
dave
dave: I tried to stiffen my back the way you suggested, but I *still* can't stand up to my wife. I'll try fiberglass epoxy next, but I'm still skeptical that any earthly material will work.
Touche! Dave,
my prsent speakers baffle should be ready tomorrow. maybe i can send some photos to you again?
the baffle is 35mm thick and with a hadn saw took me 2 days to cut. i actually cut the baffle into 2 parts to makeit easier to handle.
meanwhile i am getting the hang of fiberglass resin and how to handle it. once that is dont i will linethe box with fiberglass and open cell foam.
my prsent speakers baffle should be ready tomorrow. maybe i can send some photos to you again?
the baffle is 35mm thick and with a hadn saw took me 2 days to cut. i actually cut the baffle into 2 parts to makeit easier to handle.
meanwhile i am getting the hang of fiberglass resin and how to handle it. once that is dont i will linethe box with fiberglass and open cell foam.
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