I e-mailed the Sonic people to get more info on their product and this is the brief return I got. >>Thank you for the inquiry. This cabinet is Thiele aligned and ported, made of 3/4" plywood and OSB, butt jointed, Eminence loaded. Anybody know anything about these. Also what the heck is OSB that he refes to in the e-mail? The cab I asked about is their 115TL cab with option of a 300 or 600watt driver.I also asked to what HZ the cab was tuned to, but I guess he didn't know?