Question

What if I'm plugging in a lapel mic's receiver box to one XLR input of an AudioBox and a condenser mic to the other input with 48v turned on? Is that still safe or will it damage the wireless receiver system for the lavalier mic?

Answer 1

It depends on the receiver. Some of them are fine with it, others aren’t. I imagine that cheaper one’s could lose an output stage if you do that. Should be in the manual or you can email the manufacturer. 

I don’t recall off the top of my head if the ubiquitous Shure, Samson, or Sennheiser protects against this. All Lectrosonics receivers in the last 15 years or so, for example, are A-OK with this. 

http://www.lectrosonics.com/Support/component/com_fsf/Itemid,714/tag,Wireless,%2048,%20phantom%20power,%20damage,%20receiver/view,faq/

Answer 2

For others who are reading, you should be able to go line out (using a 1/4" instrument cable) from the wireless receiver instead of XLR into the audiobox to bypass the 48v.