We currently have 3 Audio Technica ATW-R3100BL systems. We are looking to purchase 3 more sets and have bene looking at Audio Technica ATW-3100BC. My question is should I get 3 more sets that use the same frequency's as the ones we currenty have? The range is 482-507MHZ. The new system we want to buy uses range from 541.500-560.375. Or should we go with systems that use 656.125 - 678.500? Thanks