The ticking sound is the protection kicking in. The root cause of that is unknown.

The hiss is normal. It's a combination of noise in your environment and noise induced by the circuits within the ADA. To know how much of that noise is ADA-induced, you'd have to connect each ADA input to a noise-free ground with a short, shielded cable.

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated