Hmm.... never noticed that the VP180 was 'hidden' I thought I was looking at the l80 in open air, so much for my powers of observation. I am with Alan as well, try the 180 on top of that housing right side up and upside down and see how it sounds. I wonder if the Sub could be affecting the sound somehow, if the 2 are not isolated from each other.

Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70