Hardwood audio rack

Maple is the best hardwood for audio racks. It is VERY dense and non-resonant. Rock maple is better, but very hard to work. Zothecus makes their rack frames out of maple so you might want to take a look at their stuff for ideas.

Wood technology is a science like any other. If interested, R. Bruce Hoadley is generally recognised as the expert and his books are quite readable. Briefly, wood density is a function of specific gravity, the density relative to water, and if you consult a chart you will find that densities overlap between so-called hardwoods and softwoods, i.e., southern yellow pine is more dense than walnut. Hard and soft really pertain to grain structure, not density. A complicating factor is that wood exhibits different growth characteristics during the growth season which causes early growth, sapwood to be less dense than late growth, heartwood. Pine heartwood is up to 3 times more dense than it's sapwood. maple is considered "hard" because there is little difference between early and late densities which is why it exhibits little "grain". Perhaps that is why it is judged to "sound" better. There is no species called "rock maple", that is a marketing term for any hard maple used in the construction of items like mitre boxes. All maples work quite well with carbide tipped tools and cut cleanly with little shearing or fuzzing.
Perhaps one might try holding a tuning fork to various woods and somehow measuring the resonance they store or reflect. In any event, from the cabinetmakers viewpoint, wood should be chosen for it's beauty and suitability for joinery in a given application and the tweaking left to pods, cones and wires. JMHO.

Correct, Maple is the way to go!

Thanks for the info. I agree about the beauty business. My woodman has some truly wonderful stuff. I'm thinking of going with something called tigerwood, as he has a spare half plank.

And how would a 3/4" inch solid oak rack, on an oak strip floor stack up against using maple etc for rack material? Best, Jeff