[m&d]

? when calculating the rt60, which frequency range is most critical. 250-500?


2. Is a goal to get a maximal absorption coeficient below ear level in the 250-500Hz range. If that is the case, why not use 2-3 inch thick insulshield instead of 1 inch thick.


as always appreciate the great information on this forum.


FYI

My research has led me to a product called OEM board, I think knauf board is the same thing but other companies make OEM board aswell. the 1" abs coef are similar to insulshield coated black. It is priced at $0.66/sqft. It can be found at a chain called all-interior supply.

 

[proufo]

Most materials and coverings are spec'ed from 125 to 4KHz.


I'd guess this is the minimum range that should be considered in a home theater/listening room. Perhaps RT60s for lower frequencies can and should be measured and controlled too.