Felt and Wire Cloth

[rogoll]

I've attached two pictures, one is felt made by the Duck insulation and tape company used for pipe insulation (in place of the standard fiberglass pipe wrap), and the other picture is one of 1/2" plastic wire cloth.

The felt is 3" wide by 50 ft., with a depth of either 1/11" or 3/8". The web site says 3/8" (which looks accurate), while the packaging says 1/11" (which I think is a typo). Do you think this material would work well to surround a tweeter? On many of the smaller tweeters you'd be able to cut out a hole in the center and place this around the periphery.

Can one of the more knowledgable members elaborate on the possible benefits and/or detriments of this?

Concerning the wire cloth, I purchased this to facilitate placing batting material (stuffing) in the top 19" of a 39" tall ML-TL as recommended by Paul K. I plan to stretch it across the interior and gluing/stapling it in place. Another thought I had, and just wanted to get a "thumbs-up" on, was to cover the interior end of the port/tube with this material and use a zip-tie to hold it in place (and probably glue that in place...basically the zip-tie would hold the wire cloth in place while glue dries and ultimately holds the wire cloth and the zip-tie in place). Does anyone see any potential problems with this?

Thanks in advance for your feedback.
Leonard

[rone]

Obstructing the port is generally not a good idea. Airflow past the webbing could generate chuffing noises. That said, just try it out before gluing it on.

Is that pipe insulation actually felt, or is it foam? Anyway, I think tweeter rings are usually more of a bandaid for a bad design.

[dlr]

The felt is 3" wide by 50 ft., with a depth of either 1/11" or 3/8". The web site says 3/8" (which looks accurate), while the packaging says 1/11" (which I think is a typo). Do you think this material would work well to surround a tweeter? On many of the smaller tweeters you'd be able to cut out a hole in the center and place this around the periphery.

I wouldn't consider it at all. If it's an alternative to fiberglass it will be some kind of synthetic that will likely not be effective at all for diffraction control. And be assured that diffraction control that is proven to improve both the on-axis and off-axis response is no band-aid and has nothing to do with poor design. When used appropriately by one who implements it well, it's simply one additional step towards optimal response. One may prefer to accept the lesser response without it, often due to the aesthetics, since the visual appeal frequently wins out over acoustic response. It's simply another tradeoff made in design. I prefer to try to maximize all aspects of design when I can.

I also would not use it in the interior unless you can show that it is an effective stuffing. Highly doubtful, IMO.

dlr

[mzisserson]

I wouldn't consider it at all. If it's an alternative to fiberglass it will be some kind of synthetic that will likely not be effective at all for diffraction control. And be assured that diffraction control that is proven to improve both the on-axis and off-axis response is no band-aid and has nothing to do with poor design. When used appropriately by one who implements it well, it's simply one additional step towards optimal response. One may prefer to accept the lesser response without it, often due to the aesthetics, since the visual appeal frequently wins out over acoustic response. It's simply another tradeoff made in design. I prefer to try to maximize all aspects of design when I can.

I also would not use it in the interior unless you can show that it is an effective stuffing. Highly doubtful, IMO.

dlr

Dave's research on felt and its impacts are really not to be ignored or taken lightly. I have experimented with several configurations and have found it is extremely effective at controlling the baffle step.

Unfortunately, it does not look pretty. On the Beasties I am building, I am having recesses milled into the baffle for felt, in which I plan to measure the results. That is... If the BO on the mics ever come in!

[rogoll]

Obstructing the port is generally not a good idea. Is that pipe insulation actually felt, or is it foam? Anyway, I think tweeter rings are usually more of a bandaid for a bad design.

It's felt (cloth-like fibers). The wire cloth I have is actually a smaller diameter (like about 22 or 24 gauge) plastic, 1/2-inch squares, than the picture shown. Would that cause enough restriction to create chuffing or other distortion?

[rogoll]

Dave's research on felt and its impacts are really not to be ignored or taken lightly. I have experimented with several configurations and have found it is extremely effective at controlling the baffle step.

Unfortunately, it does not look pretty. On the Beasties I am building, I am having recesses milled into the baffle for felt, in which I plan to measure the results. That is... If the BO on the mics ever come in!

Yeah, I remember you talking about that, along with some pictures. I am looking forward to hearing about your results!

[Deward Hastings]

Do you think this material would work well to surround a tweeter?

It is unlikely that it is either thick enough or absorbant enough to be of much use. But it probably wouldn't hurt anything, either. Either fiberglass or rock wool "rigid" insulation, hand "shredded" to appropriate shape, would work far better. But it's ugly, and you'd want to keep it under a grill cloth.

"Felt" is a pretty generic term . . . covering a wide range of fiberous materials in a wide range of densities with an even wider range of properties . . . "fleece" vests are felt, Stetson hats are felt, paper is felt, and so also is fiberglass or rock wool insulation. Very different properties.

It shouldn't take more than a few strands of wire or monofilament to retain insulation it a box . . . I've seen it done with cheesecloth, too. Use as open a weave as will support the insulation . . .

[Paul K.]

Regarding the wire cloth, I'd not recommend using it because of the potential restriction it could create. For acting as a "stop" for the stuffing, a window pane brace appropriately located does that very well, and you'll need bracing anyway. I don't understand why you want to wrap it around the internal end of the mass-loading port.
Paul

I've attached two pictures, one is felt made by the Duck insulation and tape company used for pipe insulation (in place of the standard fiberglass pipe wrap), and the other picture is one of 1/2" plastic wire cloth.

The felt is 3" wide by 50 ft., with a depth of either 1/11" or 3/8". The web site says 3/8" (which looks accurate), while the packaging says 1/11" (which I think is a typo). Do you think this material would work well to surround a tweeter? On many of the smaller tweeters you'd be able to cut out a hole in the center and place this around the periphery.

Can one of the more knowledgable members elaborate on the possible benefits and/or detriments of this?

Concerning the wire cloth, I purchased this to facilitate placing batting material (stuffing) in the top 19" of a 39" tall ML-TL as recommended by Paul K. I plan to stretch it across the interior and gluing/stapling it in place. Another thought I had, and just wanted to get a "thumbs-up" on, was to cover the interior end of the port/tube with this material and use a zip-tie to hold it in place (and probably glue that in place...basically the zip-tie would hold the wire cloth in place while glue dries and ultimately holds the wire cloth and the zip-tie in place). Does anyone see any potential problems with this?

Thanks in advance for your feedback.
Leonard

[rogoll]

Regarding the wire cloth, I'd not recommend using it because of the potential restriction it could create. For acting as a "stop" for the stuffing, a window pane brace appropriately located does that very well, and you'll need bracing anyway. I don't understand why you want to wrap it around the internal end of the mass-loading port.
Paul

Just to keep critters out. I've seen mice take up residence in computer equipment before, I guess because it's warmer (?). I just don't want anything crawling around inside my speakers. But come to think of it, I've seen then chew through some pretty tough barriers, so I don't guess the plastic "wire" cloth would be much of a hinderance if they wanted in.

[dlr]

Just to keep critters out. I've seen mice take up residence in computer equipment before, I guess because it's warmer (?). I just don't want anything crawling around inside my speakers. But come to think of it, I've seen then chew through some pretty tough barriers, so I don't guess the plastic "wire" cloth would be much of a hinderance if they wanted in.

Use metal wire mesh, small weave. That shouldn't be enough to cause any acoustic issues and nothing will chew through it.

dlr

[djg]

I have a couple of passive subs/ speaker stands at work. They have slot ports at the bottom, perfect for mice to enter. I put 1/4" wire mesh over the ports. Actually slightly bent and spring loaded a bit into the ports. Works for me.

[mzisserson]

Yeah, I remember you talking about that, along with some pictures. I am looking forward to hearing about your results!

All in due time.