LC3 vs SBC vs aptX vs LDAC : Key Differences

Introduction : Initially SBC was developed to provide baseline quality in wireless audio in bluetooth classic devices. Later LC3 codec was added in bluetooth LE standard version. Beyond SBC and LC3, several proprietary codecs like aptX (Qualcomm) and LDAC (Sony) dominate the premium audio space. Each codec balances trade offs between audio quality, latency, bandwidth efficiency and compatibility. A comparison of LC3, SBC, aptX and LDAC shows how each fits into the Bluetooth audio ecosystem.

SBC

• It is the baseline audio codec for Bluetooth Classic (A2DP profile) and is mandatory for all Bluetooth audio devices. It uses subband coding to compress audio streams into manageable bitrates, typically between 192 to 345 kbps, providing adequate quality for everyday listening.

• Its strength is universality and low complexity, ensuring compatibility across all devices, though it offers only moderate audio quality compared to modern codecs.

LC3

• It is the new default codec introduced with Bluetooth LE Audio (v5.2), designed to replace SBC.
• It delivers superior sound quality at lower bitrates, with support for 16 to 345 kbps per channel and sampling rates up to 48 kHz.
• LC3 is highly efficient, robust against packet loss and supports low latency modes, enabling longer battery life and improved reliability.
• It also powers new LE Audio features such as Auracast broadcast audio and multi-stream audio, making it central to the future of wireless audio.

aptX

• It was developed by Qualcomm, is a proprietary Bluetooth audio codec widely used in wireless headphones and earbuds.
• It provides better audio quality and lower latency than SBC by using adaptive differential pulse code modulation (ADPCM) techniques.
• Variants like aptX HD (higher resolution, up to 24-bit/48 kHz) and aptX Low Latency (reduced lag for gaming and video) extend its capabilities.
• However, device compatibility depends on Qualcomm hardware support, limiting its universality.

LDAC

• It was developed by Sony. It is a high resolution Bluetooth audio codec that supports bitrates of 330 kbps, 660 kbps, and 990 kbps, with sampling rates up to 96 kHz and 24-bit depth.
• It enables near hi-res audio quality over Bluetooth, making it popular among audiophiles. However, LDAC requires a strong, stable connection at higher bitrates and consumes more power, making it less efficient compared to LC3 or aptX. - Its adoption is broad on Android (due to Google’s integration) but limited in non-Sony ecosystems.

Key differences

Conclusion: SBC remains the universal baseline, aptX and LDAC push high fidelity audio for premium markets, while LC3 emerges as the efficient new standard for LE Audio. Together, these codecs reflect the diversity of Bluetooth audio; supporting everything from entry level earbuds to audiophile grade wireless headsets.