Hi pk388355, Is your model ZB601KL and firmware version WW-17.2017.2004.424? Do you mean the volume is low? Could you tell us whether this appears on wired earphone/bluetooth headphones/phone's speaker?
What app/app version are you using? Please show us a screenshot of the volume level. Do you have a music link you can provide as an example? Could you describe in more details about the sound problem?