Well, Joe's says he's paying for the Premium service, and you said that was 320kbps. So it ought to be good. Is he not getting what he's paying for - and how would he test that, assuming it's Window - or is the quality being lost on the way to, or in, this Bose thing?

But in his OP he mentions 'interference' and it being less with Amazon. What does 'interference' mean? Is there actual interference to, say, the wifi, which could affect this 'double streaming', and which he hears on Spotify because that's what he mainly plays?

Another thought: it could be his Windows box doesn't have enough processing power to decode and re-encode two 320kbps streams, and loses some data. ISTR he didn't think much of it. But why only Spotify? Perhaps because Amazon's stream is lower quality?

Joe: you'll need to experiment with different combinations of equipment and services to get to the bottom of this!