This is in response to a recent thread where @Wally mentioned comparing a cabinet before & after I tweeded it. Well, this wasn't that, but as close as I could do and still stay recent/relevant to that thread and conversation. I've played the last Harvard I built through the same 16x18 tweed cabinet & 1258 speaker since I got it finished. #2 pine, baltic birch baffle & panel, tweed & shellac. I used a Deluxe Reverb 6.6k OT on it and it's about as clean as you can get I think for an amp like this, but it still would break up after 8-9 on the dial. Biased right at 60% with JJ's. I had a little while to play today and ran the Harvard through a Jensen C10Q RI that is in the poplar cabinet I just built with the rear-mount baffle cleats. I think it's 15x19", poplar finished with boiled linseed oil and polyurethane clear coats. Same baffle ply. I wouldn't think of the C10Q being an inherently cleaner speaker than a Legend 1258, but it was today. I finally turned the volume & tone up to 12 on the Harvard, and it wasn't low-level Blackface clean, but for a tweed amp on 12, it was clean! Tiniest bit of breakup with a hard attack or a string bend, but I couldn't believe it. The volume difference was apparent, but I had to work to get any real dirt out of it. Obviously, nothing changed in the circuit. So, that leaves the cabinet & speaker. My theory is along the lines as what you read about floating baffles, but again, ventures out a little. Most common explanations say that the baffle starts vibrating and has its own resonance and adds to the sound. But, I wonder if the end result is that the speaker is attached to the baffle - with the grill & tweed between the baffle and cabinet - and the vibrations from the loose baffle to speaker frame compound with that emanating from the cone to make for a dirtier sound. I don't know - standing waves, phase issues, simply more vibrations "trick" the cone to resemble a higher output, whatever. On the other hand, wood screws through the rear cleats that join wood-to-wood for a tight mechanical fit might keep things more "balanced". The baffle doesn't have the loose play and room to create its own waves between it and the cleats, and the sound waves are more single-sourced from the speaker. A machine screw & nut through an oversized hole with tweed between the screw head & cabinet, and tweed & grill cloth between the cabinet and baffle is never going to pull up as tight as a rear mount with wood screws. Or machine screws & tnuts, but either way, the wood-to-wood match up will always be a tighter fit than a Tweed cab. Now, I have no way to back up any of this, just thoughts and reasoning. Any input & conversation is welcomed.