Motus Audio drivers
The units used in the speakers seen here (a 6” midwoofer and 1” tweeter) would cost around $570/pair. Interested hobbyists could purchase a kit, including enclosures and crossovers, for under $1000/pair. The system I heard was made of a MacMini, the versatile Resonessence Labs Invicta DAC, and Ayre amplification. Music files were played using the Fidelia playback software. Cables were provided by Cardas. I noted a sweet, smooth sound.