I want to point out that (1) 3" is not sufficient for a bass trap, depending on the construction/materials, (I use 6" OC705 and tuned traps) and (2) the plastic foam used by Auralex is less efficient than is packed mineral wool (fiberglas, OC 703, OC 705, etc.) and, therefore, needs to be even thicker for low mids.
One reason for so many rooms to be overdamped is that the user is installing more and more wideband panels in an effort to deal with sub-Schroeder frequencies and, in the process, is overdamping the mids and highs. Note that some suppliers, e.g., RealTraps, offers the option of a reflective "skin" on their traps to avoid this problem.
One reason for so many rooms to be overdamped is that the user is installing more and more wideband panels in an effort to deal with sub-Schroeder frequencies and, in the process, is overdamping the mids and highs. Note that some suppliers, e.g., RealTraps, offers the option of a reflective "skin" on their traps to avoid this problem.