What is your favorite material for loudspeakers?

I checked my old notes on birch plywood. One of the highest grades I have found is from a Finnish company called UPM. The standard UPM birch products come in 5x5 feet and 4x8 for product bonded with exterior grade glues. Price seems to be about $130 per sheet, but the importer (Plywood & Door) has a minimum of several sheets per order.
Max thickness for standard product is 1 and 1/8 inch with 22 plies per sheet.
I spoke to Rod at Plywood and Door
866. 738. 7265

Quido

Wow. That is so much more than mdf. The Finnish stuff I understand is the best. I would love to hear what some of the more expensive speakers would sound like if they were made from this stuff. That would be a project wouldn't it. Take a vanderstein and remake it in plywood. I am just a terrible woodworker so no chance here.

The prices I mentioned are unit prices. . . I believe prices may go significantly down for quantity orders.

Nanotubes. Haven't heard them yet though.
http://pubs.acs.org/doi/full/10.1021/nl802750z

Fascinating article. Complete text at:
http://pubs.acs.org/doi/full/10.1021/nl802750z
Not material for speaker enclosure. . . actually looks like completely new technology for speaker design/construction. . . possibly eventual future alternative to current electrostatic bipolar designs. Technical details are beyond me. The article may deserve its own thread. G.