GM-416-8B MLTL Corner Cabinet

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Originally Posted by Phil-G

have you considered laminating a panel?

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Took the words right out of my mouth. :D All this angle design is good experience, but folks, remember when I noted that with [ML]TLs the primary acoustic pressure was along its axis? This reduces the need for massive walls per se as long as its braced.


Now what is the most rigid, efficient shape? A cylinder. Combine the two and with some bracing along its axis, the wall can be as little as an 1/8" thick if you use a section out of sheet metal, bending wood, an appropriately large diameter cardboard concrete forming/structural tube such as 'Sonotube' or just laminating cardboard sheet over a form.


Anyway, there's myriad ways to do this and don't require fancy tools, etc., so let your imagination/needs decide how you want to do this; leaving bracing as the 'final frontier' ;) and while all this [multiple] angle stuff would seem to be needed if octogon/whatever multiple flat panel construction is desired, the reality is that the easy/lazy/cheap way now that powerful, cheap, thick, adhesives to fill large voids are available in caulk tubes, using dowels or similar of the appropriate diameter for the intended app [closet rod for large cabs is my choice] are the 'no-brainer' way to brace, tie together any angle cylindrical, stepped, slatted, cubic/whatever construction.


GM

And just in case you want to build a true round-back speaker with bending plywood. We used to build round drywall shower enclosures like this after laying 1/4" gypsum board on dampened concrete overnight.

http://www.hostboard.com/forums/hbmc...2016/11/11.jpg

mighty fast on the raw there pardner

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Originally Posted by VolvoHeretic

And just in case you want to build a true round-back speaker with bending plywood. We used to build round drywall shower enclosures like this after laying 1/4" gypsum board on dampened concrete overnight.

http://www.hostboard.com/forums/hbmc...2016/11/11.jpg

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Thats pretty sweet lookin!:cool:

Thanks, I forgot the running horizontal dimensions. :) The gross volume includes the radial 2"x.75" verticals.

http://www.hostboard.com/forums/hbmc...2016/11/15.jpg

Quote:

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Originally Posted by VolvoHeretic

And just in case you want to build a true round-back speaker with bending plywood. We used to build round drywall shower enclosures like this after laying 1/4" gypsum board on dampened concrete overnight.

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Yep, lots of options.

At this point though and [hopefully] all things considered, narrowing up the baffle a bit to extend the curve around enough to have no parallel walls is worth the slight increase in baffle step frequency. Ideally want the curve to be > 12 deg included referenced to the baffle assuming it doesn't shorten the baffle to < 34.5" i.d.. If not, then what is the max included angle?

TIA,

GM

Aren't the circular braces /frame easier to do. The ply would bend easier wouldn't it. This is what I found in my build of the A7 horn.

'Horses for courses' ;) Again, for a high aspect ratio cab we want to use bracing that minimally impedes TL pipe action to maintain high acoustic efficiency whereas curved bracing on the backside of a horn flare 'demands' curved bracing at barest minimum.

GM

Yes indeed. I'd forgotten about that. In a recent build, I remembered you mention this and followed suit.

It wasn't a TL though, but I maintained vertical braces anyway.

I was thinking only of the ply curve I guess.

Full round-back.

http://www.hostboard.com/forums/hbmc...2016/11/16.jpg