Paskal,
Sub F3 30hz
plate amp is mounted externally so as to maximize the internal volume, hence smaller looking box for more aesthetic looks. Volume about 70litre with bracing. Panels are sandwich
never did like the idea of having plate amp together as its juz bad for electronics..too much resonance
Unless the plate amp has a separate chamber in d box . But then it would take up a lot of space, hence very big box

The most dangerous to the speaers are
* when the amp starts to clip (reach its peak) forming square wave instead of the norm sine wave..hence drivers overheated n voice coil burnt.

Sharing my 12" + 15" sub system

5.2.4 even better option than 7.1.2