Two possibilities - first, and most straightforward - your old sub may be more efficient than the new one, which means it will play louder. The other possibility is that the placement you're using is not ideal.
Try a different spot in the room. Just because the Velodyne worked in one spot doesn't mean another brand will work as well in the same spot.
One trick to find the perfect placement for your subwoofer is to put the sub in your listening position, and play music with a walking bass line. Now get down on your hands and knees and crawl around the room - into corners, along the walls, everywhere - until you find the spot where the bass sounds the best (or in your case, where the bass is the strongest). That's the spot where you should put the sub.
Try a different spot in the room. Just because the Velodyne worked in one spot doesn't mean another brand will work as well in the same spot.
One trick to find the perfect placement for your subwoofer is to put the sub in your listening position, and play music with a walking bass line. Now get down on your hands and knees and crawl around the room - into corners, along the walls, everywhere - until you find the spot where the bass sounds the best (or in your case, where the bass is the strongest). That's the spot where you should put the sub.