Edifier Stax Spirit S3

Bluetooth Stax? – It's the S3 [€399] from Stax parent company Edifier. It was created in collaboration with Audeze so isn't an e-stat but an 89 x 70mm planar-magnetic 329g wireless headphone with apt-X Adaptive, its own app for DSP tuning, 20Hz-40kHz bandwidth and up to 80 hours of battery power.