Take a look at "TBI Audio Systems" subs. I have a pair of the magellin VI's and believe me they are fast and would work well with your Sonus Faber Concerto's. I use mine with Sonist Concerto 2's and cannot tell where the subs come in to play, it just sounds like my main speakers have added bass. They have an outboard amp crossover that you can hook up one or two subs to, although when two are hooked up it is still mono, that is why I bought two of their amps so I could run stereo bass.I run an extra pair of speaker cables from my main amp to the subs high level input so that the flavor of my main amp comes through the sub amps. Check them out! They do come up for sale on the gon every once in a while.Good Luck with your search.
Subwoofer choice, Sub to pair with Sonus Faber
I have a pair of Sonus Faber Concertos in my bonus room that I will be relocating to my loft so that I can do some more serious listening with them. Currently I have a very old Velodyne 10" non-servo subwoofer running with these speakers. The Velodyne is way to slow to do these 2-way speakers justice. I am considering either building a sealed sub around a Morel driver or purchasing something that is ready built. What subwoofer would you recommend to pair with the Sonus's ? I'm trying to keep this as affordable as possible while doing the Sonus's justice.