Yes V4
I began my Axiom life at the transition to V4 2013/2014 I think.
Now have all 9 channels V4.

With the sealed Bass is tight responsive quick. The DSP and design never let out any chuffing distortion. Even playing DJ Magic Mike{Make the car go boom} or any old school Bass music When they actually put a warning will damage speakers extreme Bass on the labels.

The reviews are tricky since most are older, outdated V2/V3 etc.