Please do what HD suggested first and we'll take a look. You can't compare the perceived sound quality with that you remember when auditioning in the store/dealer because of so many other factors such as room acoustics, media source, players used, listening level etc. Even if the conditions were the same, though that wouldn't be possible, you still cannot compare because of humans very poor auditory memory in such scenario, expectation bias and Placebo effects.
If the V4's impedance and phase angle characteristics are similar to that of the V3, then it could be considered a demanding load but again, you need to figure it out first using the linked calculator.
Regardless, the talks of using an Anthem AVR with no amp is pure baseless speculation. Also, if the calculator indicated you need more power, you do have to replace your AVR with one that has pre-outs.