Sorry, I missed that about the 180 in your signature.

I have not heard the QS8v4 so I cannot say. However, given what I have heard of the rest of the v4 line, I would not bet against the QS8v4.

I suspect your receiver. Not that it doesn't have enough power. Rather, its channel steering and rendering of details (accuracy) is not up to your standard.

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated