I have a bunch of 60% cotton natural fiber. It was used as insulation for cold shipments. Is it useful as dampening in a cab?
+1
And is a lot more pleasant to work with. No more worrying about nasty fiberglass particles!
There are issues...
What is the balance 40% material?
There are problems with natural fibers attracting fungus, mold, insects, moisture and so on, depending on your climate.
If that is the case, maybe the hollow polyester fibers used in stuffing pillows would be a better choice. Or the acrylic fiber used in fabric and blankets.
Comments from the members with actual experience if such, let us say, house hold materials, rather than industrial materials like glass wool will be most appreciated.
What is the balance 40% material?
There are problems with natural fibers attracting fungus, mold, insects, moisture and so on, depending on your climate.
If that is the case, maybe the hollow polyester fibers used in stuffing pillows would be a better choice. Or the acrylic fiber used in fabric and blankets.
Comments from the members with actual experience if such, let us say, house hold materials, rather than industrial materials like glass wool will be most appreciated.
I used a wool/cotton mixture in my sealed enclosures.
Those who have ported enclosures and live in warm, humid climates may be advised to use a purely synthetic absorbent material such as BAF wadding, although its performance is not as good as a natural material.
A natural material, like wool, is a more effective absorber because of the random orientation of its fibres.
Those who have ported enclosures and live in warm, humid climates may be advised to use a purely synthetic absorbent material such as BAF wadding, although its performance is not as good as a natural material.
A natural material, like wool, is a more effective absorber because of the random orientation of its fibres.
Should also be possible to seal the port with plastic on the inside. Like a plastic bag but slightly thicker. Thin enough to transmit sound but thick enough to not be easily damaged.
Wouldn't that prevent the required oscillation of the port air mass, OllBoll?
It's common for a mesh to be fitted like you say, as a means to deny access to insects and rodents.
It's common for a mesh to be fitted like you say, as a means to deny access to insects and rodents.
Only if it is fluffy enough. Dense material is not good. What material is the another 40%?
For bulk fill of sealed enclusures, yes, it's excellent. It has much more linear absorption vs frequency than anything else I tested years ago. It's commonly sold in large rolls as upholstery cotton.
Wool is by far the best performimg cabinet dampening material from a sound perspective. It just sounds better in most types of enclosures, specifically sealed boxes that aren't fully stuffed and ported boxes. You don't need as much for effective dampening which won't bulk up as much to hurt airflow to the port. If you do stuff the box completely with it, you will get more virtual increase in volume compared to other materials. Fiberglass and Rockwood aren't as linear across the entire frequency range, especially in the low end. Cotton isn't bad either but still not as good overall as wool.
The smell will add that extra bit of realism when you crank up your 60s music through your ported speakers lol.
And add extra oomph to That Smell by Lynyrd Skynyrd!
Ooooh that smell
Can't you smell that smell
Ooooh that smell
Can't you smell that smell
The problem(s) with wool are; a) it's bloody expensive, b) it is not readily available in forms useful for cabinet fill, and c) as loose fill, it settles unless suspended/held in place by threading it through netting or some similar arrangement.
I may still have the graph of absorption vs freq measurements of various materials I made years ago, will post if I can find it.
Pure wool loudspeaker felts are available which comprise of a jute central base upon which is woven / needle stitched one or two layers of pure wool yarn.
Then, there's the Wooly Shepherd! https://www.woollyshepherd.co.uk/loudspeaker-wool/
Then, there's the Wooly Shepherd! https://www.woollyshepherd.co.uk/loudspeaker-wool/
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True regarding the availability of useful formats of wool. It has to be bound in a certain thickness and density to work optimally. The loose stuff is harder to find. Other versions often are bound with a certain amount of other fiber to stabilize and make it more uniform, but that doesn't usually affect its properties enough to matter. I have used grille cloth to hold loose wool in place in high flow areas of the cab ie close to ports.
A big potential issue with fiberglass and rockwool is how easy it can get into the driver VC gap over time if the spl and vibration is significant enough to push and break away the fibers. I've reconed driver's that were used in sub cabinets damped with alot of FG and the VC windings were covered in it to the point it acted as an abrasive to the VC winding enamel and the inner VC former. It also embeds itself in the surround and spiders. Its just nasty stuff. It is cheap and relatively effective as a dampening material which is probably why people like to use it. I just would use it in a vented cab.
A big potential issue with fiberglass and rockwool is how easy it can get into the driver VC gap over time if the spl and vibration is significant enough to push and break away the fibers. I've reconed driver's that were used in sub cabinets damped with alot of FG and the VC windings were covered in it to the point it acted as an abrasive to the VC winding enamel and the inner VC former. It also embeds itself in the surround and spiders. Its just nasty stuff. It is cheap and relatively effective as a dampening material which is probably why people like to use it. I just would use it in a vented cab.
That's reclaimed cotton and synthetic fibres and would make good speaker absorbent material.
Wharfedale and others have used similar material in the past.
Wharfedale and others have used similar material in the past.
Agreed. There are fibreboard versions using the same material that are useful for vented enclosures, too.