OK. So I swore I'd never use a wireless but our current situation warrants the use of one. So, research says the X Wire is the greatest but you can't find one anywhere. Some of the more expensive Shure units like the U14S only have a frequency response down to 50HZ. I'm not sure how that would fair with a 5 string tuned to low A. I realize that any wireless might alter my tone but I gotta have low end. There is also the Sennheiser 1092 Digital. I'm told by the Director of Product Development for Sennheiser that this is the model that uses the X Wire technology. But, it's just been discontinued. I asked him why if the technology is the best. His answer was, "Don't ask, it's a long story." So, anybody out there that has experience with a pro quality unit that is reliable, available and able to reproduce the low end of a 5 string bass? I need to move on this as soon as possible. I appreciate the response.