Maj, yes, as you see, the Tube Trap outfit which Chris supplied a link to offers finished products effective at the very low frequencies which are generally the most difficult problem in a typically furnished room at home. As you also see, however, a complete set can run several thousand dollars.
It should be pointed out that one example of a "mechanically resonant" absorber is already present in many listening rooms: a relatively flexible wall surface. Typical drywall construction is sufficiently flexible(in comparison with plaster, etc., walls)that it absorbs significant sound energy at very low frequencies with the result that the room is less "boomy". Though not especially efficient, the large amount of surface area involved allows for an audibly significant effect.
The comment that electronic equalization may be more practical(including the financial aspect)at these very low frequencies still stands, and the use of a built-in equalizer such as Audyssey MultEQ, or a separate unit such as Fred and Dean, among others, have used, can be helpful. The fact is that all our listening rooms(not just Mark Johnson's)suck.
