Anyone got any figures of these materials average weights? Im gonna build a 87 liter (3,07 ft^3) 2x12 and will most likely go for pine since it´s cheaper and lighter. I will also try a 12mm plywood and insted use a lot of bracing. What do you think this will weigh if the drivers weigh 13 kg together? BTW Im going for a vertical alignment of the speakers.