My source was always Apple Music, mostly from Apple TV, in a few cases from my iPhone to eliminate the ATV as a source of the issue, and two times using USB from my Mac (again for debugging purposes).
I don't think it was an EQ problem that affected me. I think it was a bug in the room correction or spatial positioning software, and that the reason it sounded fine over USB was that one or both of these were bypassed in that situation. This based on the fact that the positioning function was disabled in the app in that configuration. But it's a guess.
I'll be talking to one of the techs from Syng tomorrow, and hope to be able to elaborate after that.
As for shipping: Be advised that these things are HEAVY. Seriously, like 42lb/19kg per unit. It's because the base of the stand is MASSIVE, probably to avoid them tipping over in a minor earthquake (designed in California, gotta love it).
EDIT: To be clear, according to their tech support they are aware of some issues with the room correction software, and an update that also includes EQ is in the works, to be released shortly.