The reason class AB amps have to be big and heavy, because one that draws 600 Watts from the wall will be dissipating over 300 of it as heat. Where as a 600 Watt class D, can turn 90% of that draw into sound, and only have a fraction of the heat to deal with.
I'm just speaking in general terms, having never seen nor heard any version of Axiom's subs.
I am pretty sure that I received one of the digitals. It was much lighter than the original that crapped out. I was initially concerned that it was not as good but realized I was forced into an subjective area not being able to A/B the two. I have since moved on and am happy with the amp and that it is still operational.
