My 3.6's are used in a system that can be configured in different ways. I have an Integra DHC 9.9 pre amp processor, when I want surround sound with my music, but I can go strictly two channel with a 1994 vintage Threshold T2 preamp. The Thiels are driven by either a Threshold SA/4e pure class A power amp, or a pair of Emotiva XPA1 monoblocs. All connections between the preamps and power amps are done with balanced XLR cables.
I have used a pair of Velodyne F1500 r subwoofers with the Thiels since they were new as well. I use a 40hz crossover point for them, as well as for the 3.6's. My sources are either a Logitech Touch streamer for my digital server collection of lossless CD rips, an Oracle Turntable with Magnepan Unitrac 1 arm and a Shure V15-V mr cartridge, or an Oppo disc player.
I have over a thousand CD's ripped to my server, and I have a little bit of everything in there as far as type of music. My favorite music is acoustic/vocal contempory folk . I like songs with lyrics that have some meaning, and maybe deliver some sort of message.