30mm thick BAF is ~£7.80/m2
50mm thick BAF is ~£15.25/m2
100mm insulation is ~£8.56/m2
So I’m drawn to the loft insulation as it is around three 3-4 cheaper by volume compared to BAF. Will it have the same/similar effect though?
50mm thick BAF is ~£15.25/m2
100mm insulation is ~£8.56/m2
So I’m drawn to the loft insulation as it is around three 3-4 cheaper by volume compared to BAF. Will it have the same/similar effect though?
I've checked out this "recycled plastic loft insulation".
To make it, plastic bottles made from polyethylene terephthalate (PET) are ground up into flakes, heated, and then extruded into polyester fibre.
I can see it having the same effect as any synthetic fibre as far as its sound damping properties are concerned.
To make it, plastic bottles made from polyethylene terephthalate (PET) are ground up into flakes, heated, and then extruded into polyester fibre.
I can see it having the same effect as any synthetic fibre as far as its sound damping properties are concerned.
I would be carefull ... about fire hazard .. and toxic smoke .. plastic may burn and make a very toxic smoke
Long-fibre wool and fibreglass loft insulation are probably the joint best for acoustic absorption (and therefore stuffing). Fibreglass is nasty stuff, of course (but fireproof).
The synthetics are pretty worthless in my experience - though any fibre as stuffing is going to have the effect of increasing effective box size.
The synthetics are pretty worthless in my experience - though any fibre as stuffing is going to have the effect of increasing effective box size.
No more or less so than polyester loudspeaker wadding which is made from the same plastic (polyethylene terephthalate, or PET) as your "recycled plastic loft insulation". And I don't hear anyone expressing ignition concerns regarding the use of polyster wadding in a loudspeaker enclosure!
Here are some burning points that I've gleaned from the internet (I seem to be at a loose end today!).
Fibreglass: will not burn
Wool: 570 °C
Cotton: 210 °C
Polyester: a synthetic polymer that melts rather than burns at 250 °C; autoignition temperature 450 °C.
BAF: a semi-synthetic polymer: 420 °C
Now, how hot can a crossover resistor get I wonder? I read that a not uncommon operating temperature is around 100 °C.
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Thanks Galu, I’m glad you were at a loose end today! I’ve opened a few pairs of speakers and found them to either be absolutely stuffed full of yellow mattress foam type stuff, or there’s a small square of polyester wadding - but maybe I’m just opening cheap speakers..
The foam is good for damping the higher frequencies.
Damping can be more of an art than a science, and sometimes less is more!
The 'Click Test' can help determine when the enclosure is properly damped (illustration courtesy of GM and planet10).
Damping can be more of an art than a science, and sometimes less is more!
The 'Click Test' can help determine when the enclosure is properly damped (illustration courtesy of GM and planet10).
BAF is bonded in form of blankets and the bonding gives a reduction in absorption when exposed to top or bottom sides , so we used that stuff by using the edges as the main entry for sound from driver.
The PET based fibre is also in form of blanket but has a better absorption , its bonding is better done, at least for the products sold here in the netherlands by " de akoestiekwinkel".
Difficult to cut though.
The PET based fibre is also in form of blanket but has a better absorption , its bonding is better done, at least for the products sold here in the netherlands by " de akoestiekwinkel".
Difficult to cut though.
This is all really useful thank you!
Regarding fire safety, the plastic insulation says on the back “conforms to flame retardant standard BS 5803 part 4 sections 2 & 3”
Regarding fire safety, the plastic insulation says on the back “conforms to flame retardant standard BS 5803 part 4 sections 2 & 3”