The hiss is normal and ought be identical from both tweeters. It is one indication that the tweeters are working. It may not be a good idea to advance the volume beyond normal listening levels to perform the test.
Noise coming from tweeter when amp get turned on
I have a Revel F52s, Ayre V-5xe (amp), C-7xe (CD player) and K-5xe (pre-amp). When I turn on the amp without player any music and I put my head near the tweeter of each speaker I can hear a hash/white noise sound (no sound coming from the other speakers). It actually has done this with all my other previous equipment. It is starting to bother me, is this normal, if not what can I do to remedy it?