I contacted ncix.com for RMA.
It can be defective and just vocals sound bad?
Edited by superfedya - Yesterday at 5:30 pm
Defective sets happen. It is most likely a diaphragm defect or or a defect in the Bluetooth circuit or the wiring, who knows?
I'm sure you'll be much happier with a replacement. Unless you are very unlucky and the replacement is also defective.