Being new to ring radiators, I don't know if this is normal or not. I have two pairs of radiators (2402H and 2405). all four of them emit a hiss. It isn't offensive and it doesn't increase with gain. I've tried them on different amps with a DBX234 crossover and connected them to the HF crossover on an L100. In all cases all radiators hiss. One is just returned from a JBL authorized repair shop having had a new diapragm installed.

I've noticed they hiss more when connected directly to a Phase Linear 400 that is tri-amped. They hiss less when connected to the HF on my L100.

Is this just the way life is with ring radiators or do I have something else going on?

Don