It should have been a marked improvement. I'm too lazy to look back, but did you:
Rerun auto eq etc.
Move the speaker out from wall if possible.
Check channel level compared to vp150
Of note is the speaker is a 4 ohm nominal load vs 8 for the 150. Not quite sure if you are using an auto eq, and a setting like all channel flat, if so you are likely throwing out amp headroom and squahing current output. I would try direct mode vs eq and see if there is a difference. As Mark sais, something sounds borked.
