Perspex (acrylic) open baffle

[sfdoddsy]

I remember seeing a few mentions here of open baffle speakers with clear perspex baffles, but couldn't find details in a search.

I'm doing a set of bedroom speakers using spare drivers from my Linkwitz-style dipole adventures, and for aesthetic reasons (ie girlfriend) am planning on using perspex. The speakers will be two ways using the 27TDFC and the W22, crossing to a sub at 90Hz or so. Basically the top half of an Orion. Since I will be listening in a very low bed, they will be 75x30.

I'll use a Minidsp for xover and EQ

The most elegant (and cheapest) baffle is a simple folded one. Like an 'L' but with a slight rear tilt. No sides, no bracing.

The place building them for me says the maximum thickness they can fold well is 10mm. I know perspex is much stiffer than MDF, and to be honest it doesn't matter if the speakers aren't the last word in sound quality compared to my mains, but does anyone have experience with perspex of this thickness?

It's only costing a couple of hundred for the baffles, and I can always brace them later, but I'm curious anyway.

[weltersys]

Assuming 75x30 is centimeters and not inches, 10mm should be plenty stiff.

I have only bent up to about 6mm, but would consider that adequate for 75x30 centimeters, 10mm plenty.

That said, an "L" in 10mm will still act like a spring, and as the speaker cone moves back and forth, so will the baffle, not good, HiFi fans.

Given the material you have chosen, a "U" shape (speaker on the bottom of the "U" would eliminate that problem, and also reduce edge diffraction in the forward direction.

[IslandPink]

For background you might look at these :

http://forum.bd-design.nl/index.php?id=16794

Built by a good friend of mine, James Doddington .
These were built from 20mm perspex, I think they were bonded/fused on the joins , which look very clean as I remember .
Bear in mind the 20mm perspex material-cost alone for these was about £900 UK about 10-15 years ago, according to James ! ( 10mm should be much cheaper ) .

These are fantastic-sounding speakers, by the way .

MJ

[mondogenerator]

the only problem being that IIRC perspex is NOT stiffer than either MDF OR decent ply, so im not sure what the point would be, unless for a purely aesthetic design......acrylic has quite a good MoE, but its still plastic rather than elastic. Lexan polycarbonate.., or (dare i say it) OPAQUE nylon 66..that may (read definately) be a different story altogether.

[vadi]

Maybe you would like get yourself 3D-printed a baffle. I'd hang the drivers on strings to remove vibrations.


Duck by i.materialise, on Flickr

They offer a transparent material, though it is the most expensive unfortunately.