Wired audio does not support absolute volume control. To ensure maximum output gain on the headphones, the wired audio default volume is set to 100%. After connecting with a wired cable, you need to manually adjust the volume to a comfortable level.
Bluetooth audio supports absolute volume control, allowing quicker volume adjustments, so its default volume is set around 50%. You can also adjust the volume using the headphones’ roller or the device’s volume buttons to find your preferred level.
This design is consistent across other brands of over-ear headphones and is not a defect. Please rest assured when using.