Who makes the best wood, mdf?

HDF has a much much greater density then MDF. This has it's benefits, but they're all nullified by the extreme increase in weight. I say use MDF with a coating of resin/hardner

http://www.plumcreek.com/products/mdf.cfm is one MDF manufacturer who claims that there definitely IS a difference in qualities of MDF on the market.Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

I just read through that site: It seems that it's just a marketing gimmick to make their product appear better then others. The only thing I can really think of tha twould affect the quality of MDF is the type of wood sawdust that is used. Because as we know different types of wood have different densities and thus different sonic speeds and resonance frequencies. The glue may be a factor, although smaller then wood type, as it determines the elasticity of the panel. Too much elasticity and the panel will vibrate and cause a lose in low frequency output. Too little elasticity will cause the cabinent to sound "hollow" with quite a bit of internal reverberation.