It would be very close. I’d use a ball end mill. There is a balance between how many passes you make and the ridges left between passes in terms of machining speed and work to finish.
I have my small speakers to finish and a few other little jobs then I will make one of the horns, so probably in a week or two.
You’ll need a lot more than one for that space though…
I think, one Yuichi horn will take just over a sheet of ply, using the cnc machine isn’t always that efficient material wise. 10 layers for the top and bottom sections (5 layers each), plus the sides which I haven’t worked out.
I haven’t worked out what is needed for the Altecs as I haven’t finished modelling the braces etc. I would imagine 2-3 sheets per box.
MMmmm unless I make the horn in the Altec out of stacked layers. It would be heavy.
Today I has been mostly making armboards for TD124’s
Quite pleased with them. Will be sending to Stu and Mark to try them out. 
They look superb
Great work
I should have given you the platters you could’ve tried yourself …
I’m really liking the look of the stacked ply.
In case the cats try to escape?
Bury 'em alive. 
No likelihood of it trying to twist? I recall having a chat with someone at TAD at a show where they were launching some speakers with similarly constructed cabs. They’d had terrible trouble with the floorstanding models in particular.
So you can’t hear the tortured mewing.
Progress is my usual glacial pace, might be useable by the bake off, depends how the week goes.
No twisting, it’s fairly locked in place by the front and rear panels which were used when it was glued up.
Main issue was caused by not using tabs to secure the layers. The U shaped pieces have moved around when being cut out so there was quite a bit of variance between them. Nothing a sander won’t solve.
Should have dowelled them. 
While cutting them out, yup, some were 1-2mm wider at the ends.
Tonight’s fun on the CNC
Armboards for the Thorens TD124 in different colours.
Also two SME adaptor plates, one for Hadcock, the other for Rega arms.
Looks a bit big to steal
