Thread: acoustic treatment tiles

Does this stuff do much in the way of attenuation? They look like they're designed to absorb sound waves inside the room, which just stops them from bouncing around, but do they stop much from escaping outside the room?

Any idea when they are going to do put up some acoustic data for the bass traps? I'm interested in this stuff for my home theatre, depending on the price.

"but do they stop much from escaping outside the room?"

That's taken care of in the installation phase.
Line a mousetrap with the acoustic foam and put it just outside the door.
repeat this outside windows etc.

Well yes, but.

there are three factors to secondary noise controll (controll after the noise is made). absorption, transmission and diffusion.

It is a given that if a "thing" absorbs sound it also must to a similar extent not transmit sound but they are seperate factors.

The archetectrual acoustical consultants are very very transmission oriented and tend not to see absortion & diffusion as valuable tools in noise control.

however if you seal up a non transmissive reflective box except for a single hole all the sound energy will come out that hole.!!!

You will very rarely get the best or easiest result in workshop noise controll concentrating on transmission alone.

working on reducing the transmission of the workshop walls is very worthwile normal insulation bats are a good cheap way to do that.

these tiles are best used in the workshop to absorb mid to high frequency sound close to source and to stop sound bouncing round & resonating before it finds it way into your ears or out the door.

I have had an absorbent panel behind my dropsaw far ages now (predates this stuff) and it significantly takes the edge of cutting aluminium both at close range and from a distance

I have some left over from an installation that I plan to put up on a wall close to my main bench area where I use routers & air drills.

much of the anoying content of sounds from the workshop is the resonant component as it rattles round inside our tin sheds before it gets out

I will refrain from raving at length but if you reduce, absorb & disperse sound as close to source as posible it travels less and your transmission barriers are more effective. As well as reducing the noise level inside the workshop.

they are primarily intended for the small studio & home theatre markets and they are doing well they are running out the door as fast as paul can restock them.

As far as the acoustic tests on the bass traps. The tests done on the tiles themselves are all kosha & certified in a propper chamber with the right gear & thats expensive.
The corner traps are also harder to test "properly" because their performance is subject to the properties of the walls ect.

There have been unofficial tests done but paul wont publish the for obvious reasons.

Most of the "bass traps" (i dont like the term) are sold into home theatre applications, localy they have been packing the customer off with a couple to try & they just dont come back.

I don't recon they are a bass trap in the true sence of the term but they are a corner absorber that is effective at bass frequecies and they do solve certain bass problems and they are primarily use for that purpose and they are good at it.

As far as acoustic data in a home theatre unless you are going to do full scale measurement & analisis data is of very little use anyway.

post getting too long Ill shut up now

cheers

just looked at your pic dylan jbl monitors MMM seroius, waht are the subs & the amps?

The 6 JBL monitors are 4430's driven by Rotel RB-1090 380 WPC stereo amps. The front subs have an 18" 2245H(?) in each driven by a Crown CE-2000 400 WPC. The side subs are dual 15" Adire Tempest's driven by a Crown Xs-900 600 WPC.

I have a custom MTM centre channel based on the 4430's drivers to install above the TV but I'm still working out how to support it. It's about 1300x600x800 and made from 32mm MDF. Heavy!

Soundman,What size of absorbtion material have you found sufficient for inside the workshop? Your comments certainly make sense.

I assume for the purpose of stoping things bouncing arround inside.
The answer is "a significant amount"!!?
that might not seem helpfull but think about it, if you want to change the properties of the room you have to treat a reasonable proportion.

it also depends onn what your problem is
behind my drop saw I have a treatment panel about 1400mm x 3000mm
The thinking was that any sound radiated toward the back of the saw at a reasonable angle will hit absorbent surface.
very little will travel below bench height.
what travels straight up will be caught by the roof insulation
so I estimate that I am purposely absorbing between 30 & 40% of radiated sound from the drop saw. at the same time eliminating the primary reflective surface.
There are other measures in place but you get a bit of an idea.
Another example
I recently treated a meeting room with the mentioned tiles.
the room was about 5m x 3 m with a cieling sloped from about 2.5 to about 4 metres all hard painted surfaces.
if you opend the door & stuck your head inside it sounded like your head was in a 44gal drum. the reverb time wasn't particularly loneg due to the small size but it was very live. It was an unpleasant & noisy place to have a meeting. using a powertool in there would have been nasty.
we put about 3m x2m on the tall wall and tapered section 3m wide douwn the ajoining wall. in all probably about 25% of the surface area of the room.
now the room still has a little ambience but sound disipates very quickly, its not uncomfortably dead but it is quite nice.
A "significant portion" treated
generaly it is best to place your absorption in the upper half of the room becaust the lower half is occupied with furniture & stuff and if you are working on a bench most of the sound will radiate above the surface.
hope thats of help.

Thanks Soundman, I get the idea.