I like tight clear base
1. Infinity Primus PS410 ($150)
2. Klipsch RPW-10 ($160)
Please dont refer others as these are the only 2 I can choose from right now.
I can't really say I have never heard any of them. I have never even heard of Mordaunt. Perhaps this link to the Velodyne site and their refurbished subs. The impact 12 looks pretty good and the impact 10 has a good review over at Audioholics, its an old review but it might give you an idea.
Audioholics review: http://www.audioholics.com/subwoofer-reviews/velodyne-impact-10-subwoofer-video