Wood choice for cabinet

[BryanC]

I have been looking at making my own cab, a fEarful 15/6.

It seems that the wood of choice is Birch, however it seems to be totally unavalible in South Africa.

What wood qualities are desired. Is it just that certain woods are light weight but still dimensionally stable?

About the only plywood avalible is SA Pine which, compared to Origan Pine, grows much to quickly in a much warmer enviroment and is offten harvested in summer and is therefore low quality.

Some TBers have used MDF. What are the advantages/disadvantages.

Is there anyone doing cut-kits that can supply to South Africa or would the shipping / quarinteening make it an unatractive option?

Thanks for any advice
BryanC

[AlexanderB]

Plywood is primarily used in pro audio for its mechanical properties rather than the audibel ones. It takes a lot of (ab-)use without falling apart. How plywood "sounds"? Well, I have never seen a commercial HiFi or studio speaker of plywood... Metal, MDF, composits, concrete, particle board etc. etc, yes, plywood no.
MDF is not as robust but is easier to work on, is consistent and "sounds better" (colors sound less).
Particle board is heavy, fragile, hard to work on and does not make a good foundation for paint, as its glue sometimes "bleeds" through.

[mid_life_crisis]

The major advantages to MDF are consistency in dimension and acoustic properties. It is generally flat and stays that way when cut unless you get it wet, unlike some woods that have a perfect shape until you cut them and suddenly have a twist or bow.
As far as the plywood is concerned, the major reason for using birch (actually baltic birch in the states) is that it is the most affordable plywood made for cabinet work, which means no void spaces and one perfect side suitable for staining. So long as the plywood you choose has those same properties, it really shouldn't matter. You're probably going to cover it, so don't buy some absurdly expensive plywood, but don't buy the junk that is intended for flooring either. Make sure it is void free cabinet grade. If you are weight obsessed, you can compare the weight per sheet as well.

[mid_life_crisis]

Originally Posted by AlexanderB

/snip/
How plywood "sounds"? Well, I have never seen a commercial HiFi or studio speaker of plywood... Metal, MDF, composits, concrete, particle board etc. etc, yes, plywood no.
/snip/.

You've never seen an exotic wood speaker cabinet? When you look carefully, they are actually veneers, which is a fancy way of saying exotic wood plywood.
I know, when most people think veneer, they picture one layer of nice wood over something cheaper, but they also make plywood from multiple layers of high end veneer sheets.
I've seen solid cherry speaker cabinets and other expensive woods, each time actually made of plywood, done that way for dimensional stability. It's been a long time, so don't ask me the brand, I've long since forgetten.

[jlepre]

Isn't MDF on the HEAVY side?

[BryanC]

Originally Posted by jlepre

Isn't MDF on the HEAVY side?

If MDF is heavy, would pine ply or marine ply be a better choice?

B

[hover]

Use the highest-grade ply you can afford / get access to. You're going to brace and cleat the cab anyway, as you want to deaden the box, so as long as it is stable structurally and dimensionally, it's a moot point. You don't want to "hear" the cab.

There has to be some ply alternative to pine ply. But if not, use that. As long as it doesn't delaminate in use, and is stable, rock it.

[billfitzmaurice]

Originally Posted by mid_life_crisis

The major advantages to MDF are consistency in dimension and acoustic properties.

The only advantages to MDF is that it's inexpensive and its smooth surface takes wood veneer well. Hi-fi speakers tend to be veneered, manufacturers rightfully prefer to use the least expensive material possible that does the job well, and neither portability nor strength is an issue. So for hi-fi MDF is a good choice.
Where plywood is concerned what's more important than what you use is how you use it. 1/2" 5 ply softwood plywood is perfectly OK if the cabinet design is optimized to use it. Commercial cabs tend to use 3/4" Baltic Birch because the labor cost of building with it is far less than with other materials, so while it's one of the more expensive materials per square foot it's one of the least expensive materials in terms of total build cost.

[rpsands]

I wouldn't use any plywood with less than a B side unless you're planning to carpet it / tolex it, myself. But I've used 1/2" arauco ply and 3/8" BC pine, etc, no problems. They require lots of bracing, but so does any cabinet.

Short story: Just use the best 1/2" Pine you can get. It's fine.

[Nightbass]

Another factor is whether you plan to gig with the cab or not. If it is going to be a studio/bedroom cab, and MDF is easily available in SA, then MDF is a viable option.