I tried it on two events. First one was a wedding, with just 10M between the transmitter and the receiver. I tried several channels but none of them solved the problem. There were some interruptions (looks it was the wind as it was an outdoor event)
Second one, there were around 15m between the speaker with the receiver and transmitter (receiver was upstairs, and transmitter on the first floor), each time people went up by the stairs, the signal was lost and there had some interruptions. Also tried several channels for the frequency, and none of them solved the problem.
The fact that there are quite big don't allow to plug them side to side on a DDJ Pioneer controller for exemple. I need to use cables to plug them.
Don’t know what happened but for me, there are bluetooth transmitters that you can buy on Chinese websites for 20€ that are doing a better job.
You’ll get an email from me soon regarding this as I can’t use it in a professional way for sure.