Wood selection for combo cabs

ezietsman

So the time for building cabinets is here. I now need to buy wood for two different cabinets and because I have no experience in this I'm asking.

One cabinet is to be built from 12mm birch ply. The other from 19mm pine. Can the gurus give me some idea what to look for when I select the wood?

rikus

ez wrote: So the time for building cabinets is here. I now need to buy wood for two different cabinets and because I have no experience in this I'm asking.

One cabinet is to be built from 12mm birch ply. The other from 19mm pine. Can the gurus give me some idea what to look for when I select the wood?

Not a guru, but for the ply you're looking for "void free" birch ply, meaning that the ply sheets don't have any holes/gaps within the "sandwich".

For the pine, just try and get as few knots as possible.

From my limited experience the way which you build the cab (i.e. box joints, finger joints, biscuit joints etc) have a bigger impact on the rigidity of the cab when working with those thicknesses.

The actual piece of wood makes a bigger difference for the speaker baffle. A good quality piece of ply will be both rigid and lightweight enough for a nice resonant "floating baffle" used in a 5e3 cab.

ezietsman

Thanks Rikus. It looks like I can easily enough get BB grade birch ply for the Marshall Cabinet and it looks like I need that same 12mm thickness for the 5E3 baffle too. I think one piece of 1.2m x 2.4m is enough for both but I haven't measured it out yet. Am I right in assuming that solid pine boards are actually made from a couple of pieces of solid pine, glued together along the edges like so:


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rikus

ez wrote: Thanks Rikus. It looks like I can easily enough get BB grade birch ply for the Marshall Cabinet and it looks like I need that same 12mm thickness for the 5E3 baffle too. I think one piece of 1.2m x 2.4m is enough for both but I haven't measured it out yet. Am I right in assuming that solid pine boards are actually made from a couple of pieces of solid pine, glued together along the edges like so:
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Depends on the width... I've seen so fairly wide one piece boards...

Attila

Rickus you seem to be in the know....

just how important is the 12 mm thickness baffle ?

why I ask is that I am building a combo (open back of course) with +- 20 mm Red Elm hard wood.

do you think I need to plane the baffle down to round 12 mm ?

Attila

rikus

Depends on what you are building, but if you are building a fender style cab with a "floating baffle" (i.e. a baffle only attached to the cab by 4 screws in the corners) the baffle plays a very important role. The whole baffle becomes part of the speaker when doing it this way transferring vibrations and acting as a sound board and if you make the baffle too thick the experts claim it kills the sounds...

Why use the elm for the baffle? Are you going to cover the baffle in grill cloth? If yes, then I'd suggest you make the baffle out of a small piece of plywood (which you can probably get on the cheap from offcuts bits at the shop, depending on size) and no one will see.

Attila

Yaa I have read a bit about floating vs non-floating, not sure that I am sold either way, with a open back the non existence of "sound box" or suspended pressure seems to me waters down the soundboard argument...... I stand to be corrected

I bought a bundle of Red Elm cheaper than pine, and as its a more a "studio" D-style amp..... I think showing off the wood will be quite tasteful, might put a Wicker cane type weave on the baffle ... but that I will dream on ... once its all assembled

lapdawg

I read so much about different materials & how they affect sound. There are so many things that people repeat, I suspect that they might not always be based on personal experience. e.g. "must be void free Baltic Birch ply". What would a small void do to sound? What do other plys sound like? How many people honestly know?
It may well sound different, but how much? There are many things in cab construction other than the material that influence the sound.

I like BB ply because its quality wood, durable, tough, easy to cut. "Void free" probably means better logs were pealed to make the ply. When i do a reproduction, I like to stay close to original spec though. It just means that you rule out chance of problems & different effects, as well as keeping the tradition. I do want to cover my next 5E3 in tweed-grain carbon fiber though...