Audioengine A5+
1 pair, 150 W
Question about Audioengine A5+
They don't have Wi-Fi, do they? Funny, why are they pictured on the "Chromecast built in" website? https://www.google.com/chromecast/built-in/audio/ Aren't they?
That is correct, the Audioengine A5+ (unfortunately) do not have Chromecast support. You would have to connect the separate Chromecast with AUX. But I can still only recommend the boxes
The answer to the second question can be found by scrolling almost to the bottom of the linked page: Chromecast.
These boxes do not have built-in W-LAN