I thought that acrylic was the same as plexiglass.....

Go contact Bobby Gately - he's the king of plexi boxes. You can find his email address over at sounddomain.com - just search his name in a the forums.....he may have a web site as well - try - www.bobbygatelyaudio.com - I'm not sure if that is right.

He can recommend the proper thickness and material for your project as well as how to attach all of your panels.