Acoustic cloth

Please note these boxes as they come are not waterproof. I cast a seal with silicone - I am sure a conventional bath sealant would work as well as the mould making rubber I used.

I used the smallest box from Really Useful Products http://www.reallyusefulproducts.co.uk/uk/html/onlineshop/rub/b00_07litre.php in recycled black and a normal hot glue gun to attach the cloth. The trick is to ensure you get a really good bead of glue adhering to the plastic, then place the cloth over it and use the tip of the hot gun to push it into the glue. Not the best method and a bit tricky but it worked. I tried other adhesives (cyanoacrylate) but it didn't adhere well. I haven't tried some other plastic cements.

Hi David Martin,

I would appreciate if you let us know what's the box's brand and which glue did you used to fix the acoustic membrane? Thank you!

Best,

Noelia

That would do nicely!

Like this? http://www.pauzuolis-rc.com/rc-shop/building-materials/mylar-film/mylar-film-3-mk It would be easy for me to swap out the acoustic cloth for the mylar on my boxes.

s by moving it to and fro, not magically passing through it)Absolutely not a crisp packet - but also not very readily available. This stuff is thinner and lighter than clingfilm and is used for the diaphragms of ultrasonic capacitance microphones that work to over 200kHz. Small mass means that the sound waves have to do less work to move it (and sound transmission across a diaphragm is done by moving the diaphragm to and fro not by magically passing through it) and therefore sound attenuation is minimal. Clingfilm is an alternative but is about 12micron and therefore more massive. Anythin in the form of a grid or mesh tends to attenuate high frequencies and cause dips and peaks in the frequency response, and directionality at lower frequencies.