1. CMF Headphone Pro doesn't support USB audio for music playback.
2. When using the 3.5mm aux-in audio cable, volume can't be adjusted using the headphones’ roller and can only be controlled via the connected device’s volume buttons. This is often the case with over-ear headphones and does not indicate a problem with CMF Headphone Pro.
Please note that if a non-standard aux-in cable (such as a 4-pole one) is used, there may be no sound output. We recommend using the official aux-in cable.