You have absolutely NO clue about speaker construction, I'm assuming. Tolex has no "dampening" affect on the "tone" coming from the speakers. Geez, where do you guys come UP with this stuff? Here's the deal with speakers. Generally what you do NOT want is for the speaker *cabinets* to be contributing any resonant frequencies of their own in terms of wood vibration. Those resonant frequencies can be random, unpredictable and fairly uncontrollable. Take a look inside a Marshall 4x12 sometime and you'll see a hunk of 4x4 (or whatever the hell that is) running between the speaker baffle and the back. That's there to help KEEP the back (which is a huge drumhead, in effect) from vibrating with a frequency that will screw with the sound of the guitar. You'll find speakers of every kind adding dampening material, including fiberglass, foam and more, to the interiors of speaker cabinets to prevent standing waves. You'll find speaker box designers adding baffles and boards to single large panels or even breaking those panels up, all in an effort to prevent "drumming" of those panels. NOBODY here has ever picked up a book on speaker design?