Well the HSU will more than likely outperform that little subwoofer. The small the subwoofer you get for the same price, the less performance you are likely to get. The STF-2 isn't very small, then again it isn't huge either. I think that the HSU will have more output, go deeper, and will be more accurate for music. I don't have any personal experience with the Velodyne, but in my experience small subwoofers like this don't stack up to larger subwoofers costing the same or less. The STF-2 is a very good subwoofer, and I plan on getting another one when my budget allows for it.