Bluetooth Classic
Bluetooth Classic is how most Bluetooth audio devices connect, including communications profiles (HSP/HFP) and streaming (SBC, AAC, aptX). The source (your phone, tablet, or computer) and the receiver (your headphones or speaker) share what codecs they support and pick a common one to use.
- A codec must be supported by both devices. The chosen codec is not always the highest available option.
- Communications profiles take priority – incoming calls and notifications interrupt streaming audio while the profiles switch. This can cause brief interruptions and a reduction in audio quality, as the same bandwidth is shared between streaming and communication.
Bluetooth LE Audio
Most Bluetooth LE Audio uses the LC3 codec (Low Complexity Communication Codec), introduced in Bluetooth 5.2. LC3 is separate from Bluetooth Classic and not directly compatible with it.
- LC3 is more efficient than SBC and supports one-to-one streaming, broadcast audio (Auracast), and hearing aid applications.
- Having LC3 on a device does not guarantee all modes are supported.
- Two-way voice over LE Audio is not yet standard in consumer headphones.
- Auracast (broadcast audio) is only supported on some LC3 devices.
- Latency depends on the use case and implementation.
How codec negotiation works
The source says which codecs it supports; the receiving device identifies the best common option. The exact choice varies by device and software. Bit depth and sample rate come from the codec and device capabilities, not a fixed setting.
Bluetooth volume
Volume is usually controlled by remote commands on the headphones using AVRCP. Loudness depends on both devices.
- Some sources have a Bluetooth volume setting separate from the main device volume.
- Streaming apps often have their own volume settings that apply before the main volume.
- Devices with Absolute Volume settings restrict some volume control options.
- Without Absolute Volume, the headphone volume may be independent from the player – AVRCP does not change the player volume, but the headphones can be adjusted separately.
Tips for a better experience
- Keep devices close and reduce interference from other wireless devices or networks.
- Update firmware and software when available.
- If using streaming paths like AirPlay or Chromecast, note that quality can vary with content and network conditions.