tonistry.

Connections & formats

Bluetooth

Also called Bluetooth audio, BT

Bluetooth is the short-range radio link that wireless headphones, earbuds and speakers use to receive audio from a phone or computer. The audio is compressed on the way by a codec, so Bluetooth is convenient rather than lossless.

05001,0001,500kbpsSBC328AAC256aptX352aptX Adaptive280–420aptX HD576LDAC330 / 660 / 990aptX Lossless~1,100FLAC (CD)~700–1,000CD PCM1,411
Commonly quoted Bluetooth codec bitrates (at 44.1 or 48 kHz) against CD audio: SBC up to 328 kbps, AAC about 256, aptX 352, aptX Adaptive about 280 to 420, aptX HD 576 and LDAC up to 990. Only aptX Lossless, at about 1,100 kbps, can carry CD-quality audio intact when the link holds; uncompressed CD PCM is 1,411 kbps.

Bandwidth is the limit. The basic SBC codec, AAC, aptX and LDAC all squeeze the audio to fit, with LDAC at its highest setting and aptX Lossless, where both devices support it, coming closest to CD quality. Both devices must support a codec for it to be used, and phones fall back to SBC or AAC otherwise. The LE Audio standard adds the LC3 codec and is slowly arriving.

Latency of 100 to 300 milliseconds is normal, which is fine for music and noticeable for games. Range is about ten meters indoors. Many DACs, receivers and active speakers include a Bluetooth input so a phone can play into a wired system; the quality then depends on the codec, the phone’s encoder and the DAC in the receiving device.

Where you’ll see this on tonistry.

  • Bluetooth is one of the connection types members pick when they draw a signal chain.

Related terms