It's good that your mics are low impedance; I'm assuming they're balanced too, and have three pin XLR connectors on the mics and on the mic cables.
High impedance mics are generally "all purpose" communication types, or fairly inexpensive hobby mics, and have cables no longer than 5-10 feet. The connectors and cables generally have two conductors, terminating in a 1/4" plug. These mics are susceptable to RFI and EMI noise because of their low signal strength and because they aren't balanced, which is why they have short cables.
Low impedance mics, on the other hand, generally have a higher output, and are balanced, so they can genrally use long cables without frequency response degradation, RFI or EMI issues.
Low impedance, balanced mics are a good thing.
