Be a little careful on Velodynes if you need a low crossover point. For some unexplainable reason, when they updated their software about a year ago or so, they changed the lowest low-pass point from 15 hz to 40 hz. Makes them unusable if you have speakers that go much below 40hz. This is true for the DD series, not sure of others.
The worst part is that they continue to advertize the 15 hz figure. Really misleading.