Subwoofer choice, Sub to pair with Sonus Faber

Thanks for everyone's feedback. My "slow bass" issue may lay in the room setup as well as the old entry level Velodyne. I am going to treat the room and investigate the EQ options before laying out any additional monies on a sub. This way I can be sure that everything is in an optimum state and I will have a better idea of how much a new sub setup will help.

I don't know what the ML Decent sub goes for used but new it is a bit out of my price range. The TBI stuff looks interesting but the TL design, as intriguing as it is, scares me a bit for music. Don't TL designs have phasing issues? I suppose I should listen to one first before thinking it won't serve the purpose at hand. How about the Sunfire subwoofers? Is their sound more geared up for home theater or do they do music well?

I have installed two 2x4' 6" thick bass traps in the rear corners of the room along with two GIK 242 Elite panels in the front. I have also repositioned the sub between the front speakers.

The combination of these changes, evaluated one at a time for effectiveness, have improved the quality of the bass substantially. The bass response is much smoother and sounds much less "one note" than it did before. The definition of the bass is much improved. However the old sub still sounds "boxy" to me and I think the passive radiator design is just not suited to what I want to hear.

The bad thing is wife has demanded that the sub be out of sight so I will probably have to procure a smaller sub and try to hide it behind one of my future main speakers. The good news is that she has also demanded I move away from monitors on stands to floor standing speakers. Since I am only a two channel guy the sub will only be used for home theater. I am not quite as critical of my HT applications as I am of my musical presentation. I should be able to try one of the small TL designs or sunfires as a result.