There are at least a dozen drivers that will work well in this box. However, if what you're interested in is primarily gross SPL and maximum low frequency extension it is probably not what you're looking for. Tuba 24 delivers horn performance to 32 Hz in a compact package, and is more efficient than other cabinets of equal size and more, but it is not the loudest and lowest box out there. It is the loudest and lowest 8 cu.ft. box out there that I'm aware of.