Andy Evans wrote:

I'm about to embark on a speaker build, and I thought I'd check in to
see what useful things other speaker builders on this ng have found
out. I've built several before, but I thought to do something a
little different. Design will be a 2-way (or MTM) box. The first
decision I've made is to use thick alu U shape extrusions front and
back.

Do you mean a 'rectangular' U-shape, like box section with one face removed?
How wide are the faces that come back, and how thick is the extrusion?


The sides will be bolted to the extrusion, and the top + bottom
screwed down, so the whole thing can be taken apart quite easily.

How would you seal the joins?


... I
could use drive units front and back and join them with a metal pipe
to stop resonances. ...

Do you mean like a compression post between the front and back panels? Would
a solid bar be better than a pipe?


As for materials for the sides and top, I could go with twin walls
and sand in between.

How about moulded panels, using some sort of resin with sand (or other
filler/mass) mixed through to make a paste?


I could get some of that interesting wood
laminate I saw at the HiFi show - very thick, from alternate layers
of thin ply, and adhesive in a kind of thin plastic tile with
labyrinthine folds.

Can't visualise where the folds come into it.


The alu U section I have is 6" wide and very chunky. Units would
therefore be restricted in size - I have some B110s to use, may also
look at Morel 142. Size would be 15" high, not decided on depth.
Width would be the 6" plate plus the thickness of the walls, which
I'd expect to be not less than 2" each side. Comments? Andy

You could go for golden ratio sizes (internally): 6" wide, 10" deep, 16"
high. Supposed to give a good spread of distances between panels, such that
standing waves are spread out (ie, better than a cube). That would give a
volume of 15 litres, less cone, magnet and internal bracing.


--
Wally
www.artbywally.com
www.wally.myby.co.uk