I just bought an RSM 190 with the BS48i-2 box and the MTX 190i box. The mic is connected to the MTX, the MTX is connected to the BS48 via 5 pin cable, and the 5 pin to stereo XLRs is connected to my mixer or preamp. The system works fine with the 9V battery in the BS48. If I turn on phantom power on my mixer or preamp, I get a squealing/screaching interference sound that drowns out the mic. Is there something special (cabling?) that I need to use phantom power with this mic? EDIT: problem solved. Didn't realize I needed to plug the 5 pin to stereo XLR directly into the MTX if I use phantom power. Once I did that, phantom power worked fine.