I was surfing around recently, and I stopped by "Stringbass.com". Not much to write home about there, but I stumbled across a "pickup comparison chart" of dubious pedigree (I say dubious because it lists the Barbera pickup as one of the worst sounding) which had a reference I had never heard of - Biesel. By the context of the reference, it appears to be a mic which can be combined with other pickups. I am interested in this idea, since I use a Realist and would like to add some clarity to it. According to this chart, the Biesel (whatever it is) is very feedback resistant and sounds great. What is it, and where can you find them?