What materials are suitable for stuffing a subwoofer enclosure? I ideally need something which is readily available in high street shops in the UK - not Acousta-stuf or its ilk.
Parts Express mentions fiberglass (is this used as loft insulation?) as an alternative on its Acousta-stuf page. Is cotton wool suitable? Anything else?
Thanks in advance.
Parts Express mentions fiberglass (is this used as loft insulation?) as an alternative on its Acousta-stuf page. Is cotton wool suitable? Anything else?
Thanks in advance.
I can´t see a disadvantage of cotton wool, but i would never use fiberglass. Glass fibers moved by a woofer for faster flying into my lungs to cause some cancer is not really what i need.
My first choice is wool http://www.doscha.nl/
My first choice is wool http://www.doscha.nl/
Dont use fibreglass(rockwool) its a mess, and it keeps on being a mess, use the padding you can buy in textile shops, fluff it up a bit and fill approx 1/4 to 1/3 of the enclosure.
I have made a few experiments with the "audio" filling (got some from the dynaudio factory when i was working for them), it makes no difference what so ever. If any difference is detected, i can guarantee you its psyco acoustics doing their thing. (besides the dinner you can take your wife out for, for the money you saved that is) 😉
Magura🙂
I have made a few experiments with the "audio" filling (got some from the dynaudio factory when i was working for them), it makes no difference what so ever. If any difference is detected, i can guarantee you its psyco acoustics doing their thing. (besides the dinner you can take your wife out for, for the money you saved that is) 😉
Magura🙂
Thanks, guys! Also, how do you recommend affixing the stuffing to the inside of the enclosure? Simple glue? Nails/tacks/staples? The enclosure is sealed if that makes a difference.
You dont fix stuffing, you just fluff it up till its laying still in one position and isnt in the way of ports and so forth.
Magura🙂
Magura🙂
Really? I'd have thought that the vibrations and air movement would eventually make all the stuffing sink to the bottom - in the case of a downfiring driver, surely this would be a bad thing. My sub isn't downfiring, but still... you sure I shouldn't fix it somehow?
Sealed or ported??
Is this a sealed or ported sub? Ported subs have no real need of stuffing at all & it can in fact be a serious detriment to the performance if over done or if blocking ports. At most for a ported sub you would just staple a piece to the back wall (opposite the driver) & one side or top wall keeping far clear of any port. If the sub crossover is low enough & steep enough even that is a waste of good stuffing material.
If it's a sealed sub it depends on your goal. If you just want to damp any higher freq reflections that survive the crossover then you can just staple some pallets to the walls are fold some around in there against the walls & it should stay pretty much in place supporting itself. If your goal is to significantly increase the effective volume of the box you need to pack it full till it's all snug & supporting itself.
Is this a sealed or ported sub? Ported subs have no real need of stuffing at all & it can in fact be a serious detriment to the performance if over done or if blocking ports. At most for a ported sub you would just staple a piece to the back wall (opposite the driver) & one side or top wall keeping far clear of any port. If the sub crossover is low enough & steep enough even that is a waste of good stuffing material.
If it's a sealed sub it depends on your goal. If you just want to damp any higher freq reflections that survive the crossover then you can just staple some pallets to the walls are fold some around in there against the walls & it should stay pretty much in place supporting itself. If your goal is to significantly increase the effective volume of the box you need to pack it full till it's all snug & supporting itself.
For sealed I'd used polyester fiber or cotton wool (not fiberglass or mineral wool, those really stink because they leave a nasty dust away. It itches like hell, and it's supposed to be cancerigen).
Line up the enclosure walls with some thin cotton batting (stapled) to control the midrange reflections in the box and back out through the cone (don't bother if this is a (sub)woofer eg <240Hz or so).
Then fill the enclosure LOOSELY with poly or wool. Loosely means that you can pass your hand through it easily. No need to fix it.
Too much stuffing would get you a 'too damped' sound and you don't want that. (that's what happened to me last week )
If you use T-Nuts to mount the woofer or the screws permit doing so by not damaging the mdf/wood when you mess with them you might take the woofer out for a couple of times and try to 'tune' the sound by taking out/putting in stuffing. You'd be surprised how much difference less/more stuffing does in a sealed box.
Line up the enclosure walls with some thin cotton batting (stapled) to control the midrange reflections in the box and back out through the cone (don't bother if this is a (sub)woofer eg <240Hz or so).
Then fill the enclosure LOOSELY with poly or wool. Loosely means that you can pass your hand through it easily. No need to fix it.
Too much stuffing would get you a 'too damped' sound and you don't want that. (that's what happened to me last week )
If you use T-Nuts to mount the woofer or the screws permit doing so by not damaging the mdf/wood when you mess with them you might take the woofer out for a couple of times and try to 'tune' the sound by taking out/putting in stuffing. You'd be surprised how much difference less/more stuffing does in a sealed box.
There is no evidence I know of that Fiberglass causes cancer and anyone who says it does is a fear-monger. It causes local discomfort to the skin, and I would certainly not suggest you should breathe it or put it in a situation where friable fiberglass can be expelled from the enclosure by air currents, but it is still the best acoustic wool product made, more effective than pillow stuffing and cheaper. Miraflex is one brand of "itchless" fiberglass.
Asbestos fibers cause cancer, due to their size and shape they are easily aspirated and are not broken down or expelled from the body. Asbestos-exposed people are at risk for a rare, serious cancer called mesothelioma.
Asbestos fibers cause cancer, due to their size and shape they are easily aspirated and are not broken down or expelled from the body. Asbestos-exposed people are at risk for a rare, serious cancer called mesothelioma.
Dynaudio is stuffing all their boxes with polyester...most of their boxes are vented!!
Magura🙂
Edit:
And they leave the stuffing loose inside the box, no fixing what so ever.
Magura🙂
Edit:
And they leave the stuffing loose inside the box, no fixing what so ever.
two points:
1) YOU know.
2) And that may be state of science in the US.
Over here some kinds of fibreglass are known to cause cancer, and EVERY not water solutable particle that lenght is < 5um, diameter < 3um and relation L : D > 3:1 is meant to be cancerogen most likely.
asbest is causing not only one kind of cancer. Reason of the high cancerogenity of asbest is the ratio L : D is getting higher with time, because the fibre does not break but split. It does not get shorter but thinner. The number of this ratio is in correlation to risk of cancer.
I think the scare about these "cancer-causing" materials is a bit extreme. My house still has asbestos siding on it, and I'm not keeling over dead or developing any respiratory syndrome, quite on the contrary I am very healthy. I don't believe the siding will cause any bit of a problem at all as is, but the real problem is when the asbestos is stirred up into the air- when the siding is removed is when the care should be taken.
Asbestos brakes in automobiles used to be common...
I know asbestos is NOT good to be breathing into your lungs, but I think it is a bigger scare than needs be.
Asbestos brakes in automobiles used to be common...
I know asbestos is NOT good to be breathing into your lungs, but I think it is a bigger scare than needs be.
The sub is sealed - and my aim here is to make the box appear bigger than it is.
So I gather that I should fluff up some cotton wool (or whatever) and add it into the box until the volume is filled - but not to overstuff the box. Just seems that some of the stuffing fibres may eventually get tangled up with the driver mechanics - possibly even getting into the venting which the Titanic mkIII seems to have a lot of (the Ventus cooling they go on about). This must be a bad thing. Is this a worthy concern or does it just not happen?
Thanks
So I gather that I should fluff up some cotton wool (or whatever) and add it into the box until the volume is filled - but not to overstuff the box. Just seems that some of the stuffing fibres may eventually get tangled up with the driver mechanics - possibly even getting into the venting which the Titanic mkIII seems to have a lot of (the Ventus cooling they go on about). This must be a bad thing. Is this a worthy concern or does it just not happen?
Thanks
Magura said:
Hi Magura,
I hope you mean fiberglass OR rockwool
Fiberglass is made from silica
Rockwool is made from basalt (usually) or other volcanic stone
As far as I know, there are no problems using rockwool. Have you heard otherwise? It would be good to know.
Thanks,
Cal
The Acousta-stuf works well I have used it on a bunch of speakers. I would however stay away from foam.
The last speaker I built I switch to foam materal which caused an a loss of bass. The box became over damped or to resistive so I went back to the Acousta-stuf which improved things.
The last speaker I built I switch to foam materal which caused an a loss of bass. The box became over damped or to resistive so I went back to the Acousta-stuf which improved things.
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