I was tlking to dj from audioque today and he said he's heard from a lot of people that the hd3 gets louder then the fully loaded btl and re mt, I was always curious of this question and everyones opinions are different but from the most he's heard the hd3 is what has had great reveiws I'm gonna be running hd3 15 on 4k in a 4.5 cubed box tuned to 40hz designed by dj so I can't wait to hear it
the HD3 on 10k would not get as loud as the BTL or MT.. those two subs are more efficient with larger amounts of power.. the HD3 is more efficient with lower amounts of power so of course it could get louder.. but then you have to factor in the install
I am sure Scott's customers would say the BTL's are louder; the same as my endusers claim about the HD3's. The truth of the matter is they both get loud as hell. Application and install would dictate for the most part. You can't go wrong with any of them.