This is all heavily dependent on the install and build. All 4 drivers are very capable and can out preform most competitors. But the 4 you mentioned are in a little different market segments and design goals. The Havoc and Xcon are your all our super sub types, the Q is an excellent SQ driver, and the BL is a stout daily ground pounder. So you need to focus in on exactly what you are going for with out thinking about being loud ( as all 4 can get very loud in the proper install ) or thinking about sounding good as again all 4 can, but heavily dependent on the install.