@Turk - I'm aware of that phenomena. If you made a plot of "virtual cabinet volume" against "weight/mass of stuffing", I'm not sure that would be a straight line that goes to infinity. I would think there'd be a limit to how big you can make a cabinet appear to the driver, say, Vvirtual/Vactual = 1.2, after which adding more stuffing starts to reduce the apparent cabinet size.
Maybe that is where you're using a trash compactor to push the stuffing into the box; I dunno. Maybe it is linear in the range of what human hands can do force wise.
I read years ago where someone stated he stuffs lightly and only to the point where the echo of his speaking voice (down the TL) was attenuated. Maybe works for a reflex or sealed enclosure as well - although those rear wall reflections might demand more treatment than that.
Maybe that is where you're using a trash compactor to push the stuffing into the box; I dunno. Maybe it is linear in the range of what human hands can do force wise.
I read years ago where someone stated he stuffs lightly and only to the point where the echo of his speaking voice (down the TL) was attenuated. Maybe works for a reflex or sealed enclosure as well - although those rear wall reflections might demand more treatment than that.
From what i read that is pretty close to the limit, you might be ale to strecth it to 1.3x.
dave
~20% increase is also what I remember reading years back.
I used this quite a bit with car woofers, back when woofers wanted large boxes. It did make a difference in practice with subwoofers (unmeasured), and was worth the extra couple bucks in materials when box size was smaller than desirable.
Joe, stuffing density for polyester is on the order of 1 lb/ft3 to move the process more towards isothermal operation and increase the "apparent volume". Density for other fibers will vary somewhat depending on thermal properties, but should be in the same general ballpark.
I used this quite a bit with car woofers, back when woofers wanted large boxes. It did make a difference in practice with subwoofers (unmeasured), and was worth the extra couple bucks in materials when box size was smaller than desirable.
Joe, stuffing density for polyester is on the order of 1 lb/ft3 to move the process more towards isothermal operation and increase the "apparent volume". Density for other fibers will vary somewhat depending on thermal properties, but should be in the same general ballpark.
Batting is much easier to tease out into the chaotic mess that works best.
The above is acoutastuff — a bit harder to properly tease then standard polyfill.
Bat is a sheet used for making quilts/coats etc, fill is used for pillows and such.
dave
so, should batting be used teased out or should I just layer it on the walls and glue it in place?
Measuring is even better. Stuffing is used to suppress standing waves inside the enclosure, and these will show up in measurements when present. Stuffing is sufficient when no standing wave resonances can be observed.
True felt rug underlayer. Quite pricey for your house (ahem, ahem) but is a very smart move to improve the sound in all rooms (in addition to your loudspeaker rooms) and used for wall-to-wall carpeting (alas, out of style). I hoarded it for years.
Although very expensive, if you look in the catalog of acoustic materials supply houses, you will find all kinds of materials that are delightful to contemplate. Sometimes it makes sense to use these - like to quiet-down an air-handler furnace.
This thread is verging on craziness. A Sabine is a Sabine and that (along with the details of freq, cost, space, moths, etc) that's the whole story.
Some discussion of classic Bozak speakers elsewhere now. Bozak filled his cabs with stuffing. I took the backs off my Bozaks (north of 140 Hz XO) and the sound was fabulous.
Funny, in some threads people are salivating over dipole sound. But here people can't image a box without a back as serving as a dipole.
B.
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i would think that a secondary consequence of overstuffing a box whether sealed our vented would be to increase the operating temp of the driver,no?
If a BR cabinet, line the walls, if sealed or TL you can just lay it in and fill the cabinet. I would tease it out, but it may be unnecessary.
dave
The grossest ones will show up in a measure. The little ones are easily missed.
dave
Sorry forgot to upload the pictures
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