That is a truly fea optimized motor. The diameter is larger than that of the 4hp, it can (if need be) have more Bl than a 4hp....no issue...
Course we could have taken the cheap/easy way out and yanked some 4hp slugs and slapped them together with no real attention to design or optimization of material use...and everybody would go "oooo ahhhhh, me want big woofer"
It'd be the same weight. What many people do not realize it is the diameter of the motor that matters more than the height. Just an old pro sound addage...that has gone to the way side from many manufacturers taking the 'more bigger more better' engineering standpoint //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif. This motor with full cooling is stronger than the previous motor with SPL tolerances, using the same coil. It will take time for people to grow and understand that this is a far superior motor than that of the old BTL. This one gives you exactly what is needed, not any more, therefore less added cost, and less of a hole in your wallet.
...at least it's different //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif way different. Everybody has a big honkin' 3 slug motor now. So we stepped out of the box and went back to what we know best //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif.