Hi BadDog,
If you have the M60's set to small in the receiver they will only be playing down to the crossover point selected (the crossover does not act as a brick wall though).
The only way to get the full bass potential from the M60's is to set them to large in the receiver so they play full range. I just want to make sure you have tried this or have the speakers set up this way.
I am not familiar with the velodyne sub you have but the SVS will make a big difference for home theater. In the case when using the subs you can set the M60's to small with a 60hz or 80hz crossover.
