How thick should a baffle board be?

[Pixel]

In order to put a check mark on my bucket list I am building an extension cabinet. It is made of 3/4" pine 18x16x9. I already put it together with glue and pocket hole screws and ran a router over the outside edges. I like how pine looks so it will be finished in poly and I have chrome hardware for it.

I am having trouble deciding whether to go with a 1/4" or 1/2" thick baffle. The speaker will be mounted off-center and the grill cloth stood off of the baffle. In general it seems most baffle boards are 1/2" and up. Is a thinner baffle board a bad idea? I rarely play loud.

Sorry I put this topic in the wrong place. It should be in cabinetry. I can't figure out how to delete or move it.

[xtian]

12" speaker? Then 1/2" minimimum for baffle.

[Mick Bailey]

I experimentally made a 1x12 cabinet with a 5/16" yellow pine baffle - actually I found it to be slightly less when I measured it. It had an acoustic ring to it and so the next cab (4x10" Jensens) was made with the same and it's exceptional. My own experience is the baffle contributes to the sound - like an acoustic guitar sound board. I would like to try one built with western red cedar to give even more of an acoustic contribution.

It all comes down to the type of music you play. For clean/jazz/blues and playing at home or in a studio I think thinner is better, but for rock a deader/thicker sound board maybe is the better choice and I'd use ply for that.

A thin sound board won't stand up to being chucked around, and if solid timber rather than ply, it needs to be semi-floating and not glued in, otherwise it will split due to expansion and contraction with humidity changes. A Tweed Deluxe has a baffle fixed just top and bottom. Timber expands considerably more at right angles to the grain direction, so it can move slightly width ways. At the same time you have to avoid unwanted rattles or resonance. I have just discovered some really interesting marine ply made from keruing and that has a lot of promise. It has a really good ring and is very hard, dense and is void-free. Exceptionally heavy, though. I may try that for a baffle at 6mm.

Also, I make cabinets with removable sections so they can be used open, semi-open or closed back. The sound and projection differences are considerable between the different permutations.

[tedmich]

I'd never do a speaker baffle in less than 1/2" although pine is pretty strong. Any bracing? If its open its a moot point as theres no bass in the case.

[Mick Bailey]

No bracing. Both cabs have three removable sections, so closed back is an option. I went with 5/16" after working on an original 50s 5E3, which was slightly over 5/16" in pine (looked to be original by the colour). Maybe it was nominally 3/8". The problem I see with thinner baffles in solid timber is their fragility, plus you need lightweight speakers. The Jensens in the 4x10" had small magnets so didn't place too much strain on the board. The 1x12" has an Eminence Cannabis Rex, so a heavier speaker.

[Pixel]

Thanks. I made a circle cutting jig for my jigsaw and just got the cutout made in a 1/2" plywood baffle. I like the removable section idea so I'm changing the back a bit so I could add another section later on.