Thread: Noise Cancelling Foam

Ring Phillip from Acoustica in Sydney.

http://www.acoustica.com.au/

Thanks BT I will give him a try.

Send a PM to Soundman as well, he knows lots about this stuff and is Capalaba.

I got some from a foam supplier locally (Sunshine Coast) and it was filter foam, the same specification as Acoustic, but sold in smallish tiles, at about a third the price per square metre.

Also look into the gear they sell for lining engine bays, it sometimes has a lead foil backing and will be a better sound deadener.

Cheers,

P

Hi Sean
Good to see you back again. The lapsteels have been put on hold since I saw you and we went on holidays.
If you give Dunlop Pacific foams a call at Sunnybank , they will have that stuff. I would warn you, its not cheap stuff and you will have to get it by the 2400 x 1200 mm sheet . Also try Cliff Electronics in Newstead, they may be a bit cheaper. (down the Valley way) I know they have it because they deal with acoustic sound deadening foams and materials. Any reasonable density foam should do the job however, as long as you dont have a heating problem. If you want some , I have some about 6 inches and another sheet about 3 inches thick which you can slice up .You can have it cos its going to the dump. Nothing wrong with it, just been sitting in my shed for too long. Let me know if you want it . PM me.
Neil.

Hi Neil,

I have made a large square enclosure 1.2m wide 2m high so the sheets may be the way to go whats the size of the foam you have left over.

I have to go to the tip as well but this bloody weather is killing me everytime I get motivated it starts raining.

I am looking at starting a new build in Feb much larger then the bed I am using at the moment its going to cost some serious $$$ but all is fun.

Hope the trip was good we should get together for a cuppa and catch up anyway soon.

I will measure it up in the morning but just a guess, the thick 6" sheet which you could slice down to 3" is about 1/2 sheet and the other 3" sheet is probably 3/4 sheet.

Look up architectural standards for sound proofing. Double walls with no connection between the two walls helps. Thick sheetrock (wallboard) mounted on "resiliant Z channel also is great. The foam will help on some of the high frequency aspect, but you're trying to prevent transmission through walls. Also check for recording studio design ideas.

Universal motors are real screamers. I have a Techno CNC machine with a 480 volt three phase 5 hp spindle that is so quiet that you can carry on a conversation right next to the machine without raising your voice. I keep wishing someone would come out with routers with similar motors.

I've also suggested to my boss about getting some sound proofing for the CNC. The router itself is very quiet but the vacuum makes a hell of alot of noise. Tell me how you go with the foam and if it made any difference.

Very loosely speaking, acoustic foam is designed for controlling sound (audio frequencies) in a listening or recording environment NOT for soundproofing, this is a totally different ball game and rarely is there much common ground. Soundproofing is incorporated in a structure, the foam or other "treatments" are applied after the structure is completed.

To reduce sound to any significant degree you need mass and to decouple the inner "walls" from the outer "walls" as much as possible, additionally, a soundproof "space" needs to be virtually airtight as even the most insignificant weakness there will allow a disproportionate level of sound to escape. If I ever get to make the CNC router I have the gear for, I'll be building an enclosure...........this will be in the form of a box within a box with minimum contact between the two, possibly neoprene blocks. Materials are likely to be heavy MDF (mass), the void between will be packed with Rockwool which is close to the most dense insulation "batt" available. The only point where this design may be compromised is where power and dust extraction have to be incorporated.

I don't think foam is the best thing for sound proofing. Have a look at the master handbook of acoustics or similar for discussion on noise proofing of recording studios etc.

Once things are appropriately constructed, I would definately go with high density fiber glass over acoustic foam for both performance and cost reasons. When I was looking in australia I found the highest performing product availible was Bradford Glasswool Ultratel:

http://www.bradfordinsulation.com.au...%2010%2006.pdf

If you require higher adsoprtion at low frequencies then double up to 100 or 150mm.

The thing is though you can't make it airtight. The vacuum, which make all the noise, needs to have ventilation because it gets very hot.

Thinking outside the box for a moment, assuming the motor is the noisy component of the vacumm, Perhaps it would be cheaper to replace it with something quieter?

There is discussion in the aformentioned book about minimizing noise through ventilation ducts etc.

This supplier has many products, not sure about cost $$$$, but they sure cover the various soundproofing needs, including that for buildings/walls. If you go this route, perhaps update the forum on your findings.

Hi Sean,
my experience with soundproofing a dust extractor may be useful.
https://www.woodworkforums.com/f200/reducing-dust-extraction-sound-46103

After speaking to Acoustica, I was tempted with using commercially available soundproofing materials, but, in the end was put off by the price.

I designed the enclosure such that if the MDF material did not provide a reasonable result, I could later add sound reflecting and deadening materials.

I would suggest getting a soundpressure meter, I found it very useful for measuring the sound level in different positions in and out of the workshop.
Zelk