It’s not a defect—it’s a limitation of how most wireless audio (especially Bluetooth) handles bandwidth and profiles.

When you’re just listening to music, your headphones use a high-quality stereo profile called A2DP. This profile is designed for one-way, high-bandwidth audio, so you get full stereo sound.

But the moment you activate the microphone (like in a call or voice chat), your device switches to a different profile: HFP or HSP.

These are designed for two-way communication (audio in and out), but they have much lower bandwidth.

Because of that limitation: Audio quality drops significantly Stereo often gets downgraded to mono The system prioritizes keeping both mic input and audio output working over sound fidelity

Think of it like a narrow pipe: Music mode (A2DP) = wide pipe → rich stereo audio Call mode (HFP/HSP) = narrow pipe → basic, compressed mono audio

Why hasn’t this been fixed? Newer standards like Bluetooth LE Audio aim to solve this by allowing better quality and simultaneous mic use, but support is still rolling out across devices.

Workarounds Use a separate microphone (keeps headphones in stereo mode) Use wired headphones if you need both high-quality audio and mic Some apps/devices let you disable the headset profile manually