Acoustic wall panels - air gap or thicker panel?...
I have some 50mm thick fibreglass panels to go on my walls.
I have been told that fitting these with a 50mm air gap behind will increase their performance. That I understand.
However, when I asked whether simply fitting a 100mm thick panel - without an air gap - would give me even better performance, I was told "no". The figures from the manufacturer say otherwise though... EQ Acoustics
What are your thoughts - 50mm with air gap, or 100mm without?...
I guess if you need lots of absorption at 500Hz, you would be best to use 50mm OC703 and a 50mm air gap, compared to the other options on this graph I made?
I see what you are referring to now. Reality is that the upper range bumps and the gradual slope at the high end, implying .9 @ 1 kHz does not occur. Also for frequencies above low order room modes, random incidence is appropriate.
Lest you take the above as rather terse, the work you did in putting together that graph is great!
Thanks for the info Andre, I still have a lot to learn!
You are welcome!
Up to what frequency (approx) are the traps effective then? How can you tell, can it be calculated or is it a rule of thumb?
For high frequency absorption, look at absorption tests. Bob Golcs has a fantastic list of them.
It looks like the thicker panels with more air gap are more effective at all frequencies then, with no down sides apart from the size/cost. Is that right?
Thicker panels are better at low end. As panels get thicker, the best materials are lighter, with ~12" and thicker being best with regular insulation, dirt cheap compared to 703 etc. The downside is the size.
Welcome to the world of acoustics, where aspirin is drug of choice for learning!
All across the country. Look under HVAC suppliers and insulation in the phone book. 703 is a generic term in the studio acoustics field for 48 kg/ft³ fiberglass and 64 kg/m³ mineral wool. Many companies make and sell such products.
I found some Knauf Insulation Rigid Plenum Liner with ECOSE® Technology in 1" and 2". It has a PCF of 3.0 on the website (but the salesman told me it was 1.5, I think maybe he is mistaken). Is it a good product for insulation?
The AFB is acsoutically equivalent to 703. Call the 800 numbers that Owens-Corning, Roxul and otheres have on their websites and ask for the dealers in your area witht he rpoducts you are interested in.