i sure learned a lot from what you just said and explanation about mics, i too have 2 sets of shure sm58($99.00 ea.) corded mics, and 2 set of audix also corded,(also $99.00 on sale ) i like the audix since it's kinda like a workhorse , i /singers dropped these mics i dont know how many times and it still works.but anyway i tend to dis-agree with what you said about 2 cordless mic using the same frequency, i have 2 identical audio technica digital cordless mics,( $199.00ea ) each with separate receivers, the first mics frequency was set by audio technica's tech people according to my zip code,( i sent it back due to what i thought was a bad mic and i was told to leave the bat. in it ) so when i bought the same type mic i set it to the same frequency, it will work if one is not in use, but if you use them at the same time it will either cut out or you'll get an intermittent sound ( i know this for a fact caused it happened to me on a big wedding annivesary while a duo was singing
) so i ended up calling tech. and explained to them what the problem was and that's what they told me," you can not have the same identical mics on the same frequency " so i set it to another freq. and now it works like a charm, and about the battery i was told to use the same kind of bat. all the time, i tend to take the bat. out , but not putting back the same pair together..and also i didnt know that you need to have a license to use a cordless mics..i know for a fact that you can only use a corded mic if you're on the stage, not off the stage due to safety reasons