One problem with in-ear bodypack receivers is that the small size of the receiver makes it difficult to include any form of diversity reception, the technology which is critical in preventing dropouts. Sennheiser's clever solution to this problem is called adaptive diversity in which the actual cable of the earphone itself serves as a second antenna. Another important feature is what Sennheiser refers to as "Focus Mode". In this dual-mono configuration, the left and right inputs from the console to the transmitter are summed to mono, For example, I could send my AUX 1 which is my mix of vocals only into transmitter input 1. Then into transmitter input 2, I could send AUX 2 from my mixing console, that being a mix of the whole band. Now, each individual bodypack receiver can be adjusted with either "more vocals" or "more music" using the balance control on the bodypack. The resulting mix goes equally to both ears. Focus Mode could also be used to send two distinct mixes to different users. Monitor Mix 1, coming from my mixer's AUX1 goes into the L transmitter input. Monitor Mix 2, coming from, say, AUX2 goes into the R transmitter input. Users who want Mix 1 pan hard Left; users who want Mix 2 pan hard Right. (There is about 3dB of bleed audible in either case.)