Ethernet or wifi streaming and white noise on Mac

[IanG-UK]

Good point Alex.

Maybe terminology has lapsed and we need to classify these noises as (a) continuous disturbance; (b) drop outs; or © crackles.Or something better.

As far as I can discern, crackles/drop outs are network related whereas continuous disturbances are clock related. But others here may be able to categorise/establish cause/identify solutions better than I can.

Ian, I think describing white noise as "continuous disturbance" is being too politcally correct.
White noise == very loud (although that depends on the current volume) steady (not throbbing ) hissing coming from both speakers (mainly the tweeters and mid range drivers). Occasionally, it starts with music barely audible against the relatively quiet hissing background, but soon switches to full blown loud hissing, with no music discernible whatsoever.

To those attempting to stream over WiFi (vs Ethernet) in any part of the music chain, this, in my opinion, is a hopeless undertaking, if you go beyond the CD format, unless you live in a secluded mansion. Even many network streamers (e.g. Moon MiND) specify in their documentation that you have to be fully wired, to stream above the 16/44.1 resolution. But then those streamers, accept the compressed files over DLNA, whereas AIR sends uncompressed packets to Devialet, further increasing the network traffic.
Incidentally, I was never able to use WiFi even for 16/44. I purchased an AirPort Extreme, and trouble shot the WiFi network, to make sure I was streaming on an empty channel. All to no avail. It would play fine one day, and give me hiccups the next one. Only later did I realize that my neighbor's wireless phone was responsible for those interruptions.
Going fully wired (to my dedicated AirPort Extreme router) solved all problems for me, except for the occasional white noise, which issue, it appears, is getting better and better with the recent iterations of AIR (beta-1 and beta-4).

We may be talking about different noise Alex.

I get very similar experience whether ethernet or wifi. Maybe the noise comes slightly quicker with wifi but I have not timed this. The timing is too random. 

The noise I get is definitely not crackles or drop outs. It is continuous, starting quietly, and becoming more prominent. It is not necessarily a volume thing - more that the noise swamps the music, as though the music almost disappears. The Devialet AIR software engineer has heard it and seen the OS experience on my MacBook as the interference happens. He is absolutely clear that it is a clocking issue - so for me to describe it as a generic white noise is probably inaccurate. But I cannot think of how to describe it otherwise!