In the context of CNX Software’s topics, SBC usually stands for “Single Board Computer”, but SBC also stands for “SubBand Codec“, a standard and mandatory Bluetooth codec which is supported by all headphones, portable speakers, car head units, and basically everything that plays audio over Bluetooth.

SBC is known as a basic and low-quality Bluetooth codec, so people will often recommend using other codecs such as aptX, AAC or LDAC wherever possible, but ValdikSS has submitted a patch for Android which improves Bluetooth SBC codec audio quality on most existing devices, allegedly making it as good as the high quality aptX HD codec.

ValdikSS explains this basically works by increasing the bitrate:

My patchset bypass Android Bluetooth stack limitations and increase bitrate from stock 328 kbps to 452 or 551 kbps, depending on device speed capabilities. It’s already merged into LineageOS 15.1 and 16.0, Resurrection Remix and crDroid alternative Android firmwares.

You’ll get the full detailed technical explanation in “Bluetooth stack modifications to improve audio quality on headphones without AAC, aptX, or LDAC codecs” post which also links to another interesting post providing in-depth information about profiles, codecs, and devices used by Bluetooth audio applications. You’ll also learn that the great differences claimed between codecs are mostly a myth and that Bluetooth 5 support does not bring anything to audio transmission.

ValdikSS patchsets are for Android 8.1 and Android 9.0, but he also told CNX Software those audio quality modifications could be also used on Windows with Toshiba Bluetooth stack, and on Linux with a patch for PulseAudio.

If you’re not quite ready to test it on your phone, you can compare SBC dual channel audio quality against the traditional SBC joint-audio and aptX right in your web browser.