Office partitions as sound panels

Good suggestion. Thicker is better.

Limited to high frequencies in all liklihood but dependent on the specific panel, of course.

Those 1" Auralex panels are effective for high-frequencies and will have an audible consequence. However, much thicker panels are needed to extend the absorption into the midrange or lower. An excess of thin panels can make a room sound dead without doing anything to tame modes and resonances.

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.

"Really good speaker placement" is undeniably
essential but it cannot fix the acoustical problems of a room
with unfortunate dimensions and inappropriate surfaces (lack
of absorption/diffusion). You just make the best of a bad
situation.