Baffle thickness

[teleblaster]

Does thickness effect sound. I know my gibson has a thin redwood baffle and it sounds great. the old fender tweeds looked as they were just cheep plywood.

[SatelliteAmps]

Yes. The baffle material and thickness both affect tone.

[teleblaster]

Whats the tone of crappy thin plywood?

[PRNDL]

The general idea is the entire cabinet vibrates. A tuned cabinet resonates.
The baffle board transfers speaker vibrations into the cabinet.

From this perspective, everything about the cabinet matters - the cavity (dimensions of width and depth as compared with wavelength), the density and thickness of the wood, and how well the vibrations are transferred.

Particle board has completely different tonal characteristics than plywood (and may chosen for its acoustic deadness when vibrations are not desirable).

As with an acoustic guitar, a thin baffle board vibrates a lot more than thicker wood.

Also consider the acoustic qualities of a fine violin.
The tone of a Stratovarious is based on the whole - aged wood, thickness in specific areas, bracing and support in other areas, lacquer, etc.

BTW - you might be really surprised to know the "cheap" quality of wood used in many awesome sounding vintage amps, although much could be said about that word. Vintage "cheap" wood may be quite hard or impossible to find today, especially so for plywood.

[mbratch]

Whats the tone of crappy thin plywood?That would depend upon the amp and the guitar. There's not a universal adjective one could apply.

Can you define what you mean by "crappy" and "thin"? How thin is it? Is it crappy just because it's thin, or is there something else that also makes it "crappy"?

[teleblaster]

1/4" plywood, Maybe redwood for my gibson GA20T amp. Thats what came with it. Long gone though. i have a replacement small box deluxe repro that fit but its 1/2" than what came with the amp. just wandering if the thinner baffle would make any difference. The amp is the size of a small box deluxe

[dtube]

I have a Dane-made Silvertone 1481, which is basically a tweed Champ circuit. These amps were not known for their stellar craftsmanship. The baffleboard is made out of the same stuff as pegboard and is about the same thickness. I've had to drill new speaker mounting screwholes a couple times (actually, a hot butter knife would probably go through that stuff). I put a crappy Utah ceramic out of Vibro Champ in it and bypassed the preamp cathode with 25uF and that amp absolutely rips with a set of humbuckers. The whole amp vibrates on low notes. Neil Young described the first time be plugged in that Deluxe by saying that it sounded like the room was going to explode. I'd describe this 1481 in similar terms. The thing sounds like its ready to blow up at any time. Whether or not that thin baffleboard contributes to that or not, I have no idea. But, it sure makes we wonder.
-Darren

[mbratch]

1/4" plywood, Maybe redwood for my gibson GA20T amp. Thats what came with it. Long gone though. i have a replacement small box deluxe repro that fit but its 1/2" than what came with the amp. just wandering if the thinner baffle would make any difference. The amp is the size of a small box deluxeFor reasons PRNDL described, the thickness and material of the plywood indeed makes a difference in the sound of the amp. But exactly what difference in tone it makes would have to be determined by experiment.

[phsyconoodler]

Fender originally used pine for their cabinets and thin plywood baffle boards.Not because he was on to any magic tone quest,but because it was the cheapest wood around at the time.But a guitar amp is not a streo,so as luck would have it,it was the right formula for killer guitar tones.
The Tweed Bassman is a great example of this.It has a 'floating' baffle board that is attached only at 4 corners.It becomes part of the sound by vibrating and breathing with the speakers and cabinet.
Thin is good for a Tweed amp and even the blackface amps seem to sound better with plywood baffles.As soon as Fender sold out to CBS they switched to particle and pressboard and the tone suffers.
A guitar combo amp is definitely like an acoustic guitar.It needs to vibrate to produce the tones we all love.Pine does it and so does thin plywood.
Guys who make cabinets out of thick solid hardwoods and thick,daddoed baffle boards miss out.They still sound good,but not AS good.

[chaz]

One thing I've noticed is that the modern baltic birch ply is stiffer for the same thickness compared to the old domestic plywoods due to its having more layers. I've been happy with the results substituting 1/2" baltic for old 3/4" ply applications up to about 40-50 watts. YMMV

[Swarty]

To further Psycho's comments, the floating, thin baffle of the tweed amps and '50s Gibsons is akin to the vibrating top of an accoustic guitar and plays a major role in that chewy, gooey midrangey honk. A thick, solid, non-floating baffle will not produce these tones although it will produce tighter, punchier bottom. So as with most of this stuff it is just a matter of what floats your boat. It would be pretty boring if we were all chasing the same tone.

[VaughnC]

To further Psycho's comments, the floating, thin baffle of the tweed amps and '50s Gibsons is akin to the vibrating top of an accoustic guitar and plays a major role in that chewy, gooey midrangey honk. A thick, solid, non-floating baffle will not produce these tones although it will produce tighter, punchier bottom. So as with most of this stuff it is just a matter of what floats your boat. It would be pretty boring if we were all chasing the same tone.
Yup, I agree with this assessment. I built my homebrew 12/10 combo out of 3/4" pine, baffle & all, and I hear the warmth of the pine but with a nice tight bottom too.
http://mysite.verizon.net/vaughn47/amps/BKrear.jpg

[Roundtone]

My experience is with pine enclosures and floating baffles. The last one I built had a 1/4" thick baffle (with a 1/4" lip for the grill cloth) attached at four corners. Both the top edge and the bottom edge of the baffle was completely unattached. It was a SE champ circuit with an 8ohm secondary output tranny (5000K primary) and a 12" 8ohm alnico. I was VERY satisfied with both the tone and the responsiveness with a 5" opening in the back. Bass was a little loose at higher volumes, but the mid distortion was too good to mess up. Without the back panels it sounded like a much bigger amp, but I liked the controlled sound with the panels. IMO as long as the baffle is heavy enough to support the dead weight of the speaker without bowing you should be fine. The Silvertones I have seen with the paperboard (or masonite) baffles deteriorate with exposure to humidity so they should be inspected for signs of collapse. Plywood will resonate to a much greater extent than masonite. 1/4" seems to work just fine with the lip so that the baffle mounting screws have a 1/2" of material to secure them. Weight reduction is the single greatest advantage to pine and thin baffles, again in my opinion.