To some degree, I would have to admit that there is some drop-off with the 150 sitting off-axis but this can really only be determined by putting a "pink noise" signal through it and measuring that signal in that frequency range with an SPL meter. Realistically, when measuring in the same manner, there isn't a horizontal center channel speaker out there, regardless of price, that doesn't have some drop-off to one degree or another when moving off-axis, that is just the nature of the beast and the compromise of the center channel design. Believe me, I have tried and measured several brands. The only one that didn't have this issue was the now discontinued expensive Omnipolar channel designs from Mirage. Their particular tweeter design and positioning in the cabinet provided a pretty consistent signal as much as 80-90% off-axis, quite unique.
Prior to the introduction of the VP180, I was looking for a large center channel and tried one from Elemental Designs, the large A-6T6 5 driver behemoth from that company. Unfortunately, it had, by far the worst, off-axis performance of any that I have used, 2 and half to 3 db drop-off in level moving as little as 10-15% to the left or right of the sweet spot. Of course, it was returned almost immediately.
