I've just finished building my first sub and after doing some sound measurements I have decided to make some corner bass traps. This is because I have a very uneven room response (see graph). For example, I have a big -22db dip at around 28hz or 40hz, depending upon listening position and/or sub placement.
I have examined this informative list of insulation material coefficients at:
http://www.bobgolds.com/AbsorptionCoefficients.htm.
However, could people suggest the most suitable material that can be purchased in Australia?
At this stage it appears to be:
Brand: CRS Bradford - Rockwool
Product: Glasswool Anticon Roofing Blanket - R2.5 Thermofoil
Specs: 95mm thick & 0.72 at 125hz
Can anyone suggest a better alternative(s)?
I have also ordered a Behringer Feedback Destroyer.
I also would like some advice on bass trap placement. As the diagram shows, the room is a T shaped garage. It is also a laundry area. The room is made of concrete block. My car is positioned left. I have partitioned part of the garage off with a very light flat cotton curtain as shown. The corners are marked with the proposed trap positions with the exception of the bottom left corner which I may also put a half leangth trap above the laundry sink. Unfilled box shapes denote shelving areas (which could be rearranged). Sub far right, listening position in pink. Yes, there is a garage door behind the car.
I'd love to hear feedback/suggestions as to a different or better layout...
In addition to my above question re suitable insulation material, my biggest questions are:
a) should I place a trap as shown in the top left corner (is it worth it)?
b) how much does the car and light weight curtain change the room from a T into an L?
c) will the traps and/or BFD fix/improve my response?
d) are traps using triangle chunks filling the entire corner better than 4inch sheets fitted diagonally across the corner?
Cheers