|A Typical Speaker Baffle|
Thin plywood tends to be louder and have better low end than pine of the same thickness. 3/4 inch birch has more projection and gives you more of the speaker sound and less of the cabinet itself. Closed-back cabinets will be tighter and have a slight edge with birch baffles.
The thickness of the baffle has a great deal to do with the sound. For instance, most tweed amps from the 50’s used either ¼ inch or 5/16 inch pine, which sounds open and loose. Amps made in the 60’s generally have a thicker baffle and have a tighter, cleaner sound as a result.
A floating baffle is attached at 2 points either top and bottom or side and side. The 1959 Fender Bassman is a good example of a top and bottom floating baffle while the Super Reverb is a good example of a side to side floating baffle. The Bandmaster 2×12″ speaker cabinet does not have a floating baffle. It is attached on all 4 sides to be very rigid and tight. A thinner baffle works best for a floating baffle because it vibrates more and those vibrations blend with those of the speakers.
|Center Stabilizer Piece|
If you ever open up a closed-back cabinet, you’ll notice that there’s a piece of wood in the center of the cabinet that connects the baffle to the back panel (seen on the left). That’s designed to allow the baffle and back panel resonate in phase, and without it you’d have a lot of phase cancellation, and a cabinet with a lot of frequency response peaks and dips as a result."