I got one of the new 6666 Pro radios a while back and have been checking it out. One of the things I have noticed, is that the microphone has a big hollow sound. The big front grille on the mic looks great, but it is not functional. The stock electret element is in a tiny hole right below the grille. And the grille is not blocked off like on the other Anytone mics which leads to the hollow sound. The stock electret element is good for DX, but doesn't have a full sound. The solution is to use elements from a telephone handset or from a speaker phone. The telephone elements are tailored to voice because the telephone people want you to sound like you. Radio people should want that too.