Cabinet construction

[JoeGags]

Disregarding the actual metric thickness of Baltic Birch plywood and using the closest imperial measurement - is 5/8 a good choice for speaker cab construction? Rigid enough, but saving a little weight as opposed to 3/4? Any opinions? Thanks

-Gags

 

[EdFarmer]

The last I built cabinets (it has been a LONG time) I used 3/4 marine plywood for the front and 5x8 for the rest. I'm not sure that I was happy with the 5x8 but I was on a budget. Today, I would likely use 3/4 all around and invest in good quality carry handles or casters (depending on the size).

 

[xtian]

Fine for a 1x 12 cab, especially an open backed one. 4x12? Use 3/4”.

 

[Steppin' Wolfe]

What cab/amp? As xtian notes, different applications call for different options.

 

[DaveK]

FYI, 15mm (5/8") is the standard size Marshall has used since the '60s 4x12 cabs.
I think it's more than proven itself given the sheer number of Marshall cabs still kickin around the globe.

 

[Steppin' Wolfe]

FYI, 15mm (5/8") is the standard size Marshall has used since the '60s 4x12 cabs.
I think it's more than proven itself given the sheer number of Marshall cabs still kickin around the globe.

I did not know that, but I always sensed that Marshalls were not as heavily built as some other cabs. There are all sorts of reasons why one would or would not choose a certain material...type and size....for a cab.

 

[fingertip]

Vintage 'drip-edge' Princetons were seemingly built with very cheap materials and they sound great. I have a home-made 4x10 where I used open back 3/4" Birch and I have a THD 2x12 which is a lightweight ported cab. My homebuilt sounds better. Sounds amazing. But I have no way of explaining why.

 

[dirtyguitar]

Vintage 'drip-edge' Princetons were seemingly built with very cheap materials and they sound great. I have a home-made 4x10 where I used open back 3/4" Birch and I have a THD 2x12 which is a lightweight ported cab. My homebuilt sounds better. Sounds amazing. But I have no way of explaining why.

Because you like 410s better than 212s?

 

[Trebor Renkluaf]

Because you like 410s better than 212s?

That's what I was thinking as well. The THD 2x12 is a sweet sounding cabinet.

 

[fingertip]

Could be open back vs ported or maybe the age of the speakers or how the 10's voice better with the amp. I know little about the complicated science of aural engineering. I just blundered along and got lucky.

 

[Khromo]

You can use 1/2" if you brace it right!

This is how guys build pro sound cabs for very high volume, and while there is usually not much of a weight saving after all the bracing, a well braced cab built with 1/2" will resist vibration better than a cab built with 3/4" but no bracing.

You don't need the bracing on open backed cabs, except for maybe on the baffle, or for really large ones. Or for very loud volumes!

This is eventually going to be a pine open back combo cab, but it shows what is called a shelf brace (or a million other things!) and how it might be used in a sealed cab.

The general approach is to use 2-3" braces, glued on edge, about 2/3's of the way across the long dimension of the largest panels. In a sealed box, connecting opposite panels is preferred and ideally the braces connecting the three sets of opposing panels should connect as well.

It is best to install all this at a slightly cockeyed angle, to minimize standing waves. If, like the ******* who built that thing, you have a lot of time on your hands, you can radius all the edges. The hi-fi guys say it reduces "turbulence". Well, I don't know anything about turbulence, but it can bring down airplanes, so I don't want any of that stuff around me or my cab. Turbulence kills.

Sometimes you might use 5/8 or 3/4 for your baffle, but 1/2 will do, even for high volume in sealed boxes, if you brace it right.

Here are some more pictures of braces.

The cream 2 x 12 has a sealed back as well, and the brace is useful at keeping that big panel from vibrating at higher volumes.

Bracing. It's like brushing your teeth. At least that important.