Tom Reid wrote on Thu, 09 March 2006 20:49 |
The 718 and 728 use 18mm 13-ply birch plywood. The rest of the line is 15mm 11-ply birch plywood.
|
Yes, and they talk about a bit about bracing:
"SRX700 is constructed of top quality birch plywood and coated in JBL's rugged DuraFlex™ finish. Extensive use of internal braces and bulkheads makes the enclosures extremely rigid. This reduces acoustic losses caused by panel resonance. "There is no bracing in the 712M - I wouldn't think any is necessary as the cabinet is a compact 13.75 in x 21.5 in x 10.25 in.
The real key to their light-weight are the neodymium motors, both on the 2262HPL differntial-drive woofers and the 2431H CD (3-inch). The aluminum baskets on the 2262HPL are very stout, but incredibly light, as is the motor. The baskets give great access if they were to ever need a recone, but that is pretty unlikely. Not sure I wanna try and align that triple VC anyway...
Here's a composite pic of the 2262HPL, and the EQ settings saved in my Protea RD compared to those of an EV wedge.