SBC, the Sub-Band Codec, is the mandatory codec of the Bluetooth A2DP profile: every stereo audio device claiming A2DP is required to implement it, which makes the SBC codec the universal fallback. The specification's recommended settings run from 127 to 345 kb/s through a negotiated bitpool. Independent testing measured 308 ms of lag on an Android rig and 259.8 ms across five earbud models. Devices that share a better codec use it; SBC is what runs when they do not.
Figures on this page were checked September 2026. Every table row carries its source and access date.
Spec summary
SBC is the codec the A2DP specification itself mandates, which is why it runs on more devices than any proprietary alternative.
| Field | Value | Source / as of |
|---|---|---|
| Name | Sub-Band Codec; spec text: "low complexity subband codec (SBC)" | A2DP 1.3.2, Section 4.2.1, 2026-09-22 |
| Steward | Defined inside the Bluetooth specification; not a vendor product | A2DP 1.3.2, Section 4.3.1, 2026-09-22 |
| Status | Mandatory: encoder required in sources (SRC), decoder required in sinks (SNK) | A2DP 1.3.2, Section 4.2.1, 2026-09-22 |
| Required sampling rates | 44.1 and 48 kHz mandatory in sinks; 16 and 32 kHz optional | A2DP 1.3.2, Table 4.2, 2026-09-22 |
| Channel modes | Mono, dual channel, stereo, joint stereo | A2DP 1.3.2, Table 4.3, 2026-09-22 |
| Bitpool signaling range | 2 to 250, negotiated per link | A2DP 1.3.2, Section 4.3.2.6, 2026-09-22 |
| Third-party table row | 320 kbps, 16-bit, 48 kHz | SoundGuys comparison table, 2026-09-22 |
The mandate wording is worth reading closely: it is why an SBC decoder ships in every Bluetooth speaker, headphone and receiver that claims A2DP, regardless of what else the box advertises.
Bitpool and bitrate ladder
The bitpool is the knob. A source raises or lowers it to trade fidelity against robustness, and the specification notes the bit rate can change dynamically this way without suspending the stream.
| Setting | Sampling / mode | Bitpool | Frame length | Bit rate | Source / as of |
|---|---|---|---|---|---|
| Middle Quality | 44.1 kHz, mono | 19 | 46 bytes | 127 kb/s | A2DP Table 4.7, 2026-09-22 |
| Middle Quality | 44.1 kHz, joint stereo | 35 | 83 bytes | 229 kb/s | A2DP Table 4.7, 2026-09-22 |
| High Quality | 44.1 kHz, mono | 31 | 70 bytes | 193 kb/s | A2DP Table 4.7, 2026-09-22 |
| High Quality | 44.1 kHz, joint stereo | 53 | 119 bytes | 328 kb/s | A2DP Table 4.7, 2026-09-22 |
| High Quality | 48 kHz, joint stereo | 51 | 115 bytes | 345 kb/s | A2DP Table 4.7, 2026-09-22 |
Official footnote: block length 16, loudness allocation, 8 subbands. Sinks are required to support at least the High Quality bitpool; larger pools are optional.
Two independent figures outside the spec line up with the top of this ladder. Sony's LDAC page uses a 328 kbps stream at 44.1 kHz as its payload baseline, the same number the spec's High Quality joint-stereo example produces, and the SoundGuys table prints 320 kbps for SBC. The spec derives each rate from frame length, sampling frequency, subband count and block count with the formula in its Section 12.9. The cross-codec rate view is our bitrate bench.
Measured latency
| Metric | Measured | Source / as of |
|---|---|---|
| Android rig average | 308 ms across four Android phones | SoundGuys (Bluetooth receiver + instrumentation rig, not headphones), published 2021-03, accessed 2026-09-22 |
| Truly wireless earbud average | "259.8 ms. However, this is only obtained from five products, one of which is noticeably higher than the others." | RTINGS latency research, accessed 2026-09-22 |
| Baseline status | AAC is described as "expected to be, at the minimum, as low latency as SBC" | RTINGS latency research, accessed 2026-09-22 |
The two programs land in the same band by different routes, and both treat SBC as the reference point other codecs are measured against. At roughly 260-310 ms, SBC sits far from video-sync territory; the practical fixes live in our Bluetooth audio delay guide. The cross-codec view is our latency bench.
Device and OS support
| Platform / device | SBC support | Source / as of |
|---|---|---|
| Any A2DP-certified device | Required: the mandate applies to every device claiming the profile | A2DP 1.3.2, Section 4.2.1, 2026-09-22 |
| iPhone | Yes, alongside AAC; iPhones support no other Bluetooth audio codec | SoundGuys codec support article, 2026-09-22 |
| Android phones | Yes, as the mandatory baseline beneath optional codecs such as aptX and LDAC | A2DP mandate + codec profile pages on this site, 2026-09-22 |
| Aftermarket transmitters and receivers | Any unit claiming A2DP carries SBC; proprietary codecs are the add-on layer | A2DP 1.3.2, Section 4.2.1, 2026-09-22 |
Pairing behavior
SBC is what a link runs when negotiation ends without a shared optional codec. The specification's rule reads: "When both SRC and SNK support the same Optional codec, this codec may be used instead of Mandatory codec." Invert that and every mismatch lands on SBC: an iPhone source against an aptX-only receiver, or a Windows box without drivers against LDAC headphones. iPhones support AAC and SBC and nothing else, so every iPhone link runs one of those two. Per-model phone detail lives in our iPhone codec compatibility page.
FAQ
Sub-Band Codec. The A2DP specification calls it the low complexity subband codec and makes it the one codec required of every streaming device: an encoder in the source, a decoder in the sink. The name describes the design, which splits the audio band into sub-bands before coding.
On every Bluetooth audio link that fails to agree on a better codec. The A2DP rule is that an optional codec runs only when both ends support it, so any mismatch lands on SBC. iPhones pair AAC with SBC and nothing else.
The bitpool is negotiated per link within a signaling range of 2 to 250. The specification's recommended settings work out to 127-345 kb/s, the often-quoted 328 kb/s is the High Quality joint-stereo example at 44.1 kHz from the same official table, and a third-party codec table prints 320 kbps.
It adds the kind of lag a camera shows. The SoundGuys Android rig measured 308 ms on average, and RTINGS puts the truly wireless earbud average at 259.8 ms from just five products. For video, a low-latency chain is the fix; our Bluetooth audio delay guide covers the options.
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- Bluetooth SIG, Advanced Audio Distribution Profile 1.3.2 (A2DP): Section 4.2.1 "The A2DP mandates low complexity subband codec (SBC) to ensure the interoperability. The device shall implement a SBC encoder when the device is the SRC, and a SBC decoder when the device is the SNK."; Section 4.3.1 "SBC is mandatory to support in this profile."; Section 4.2.2 optional-codec rule; Table 4.2 sampling frequencies; Table 4.3 channel modes; Section 4.3.2.6 bitpool range 2-250; Table 4.7 recommended parameter sets (127-345 kb/s examples); Section 12.9 bit rate formula. bluetooth.com/specifications/specs/advanced-audio-distribution-profile-1-3-2/ (spec PDF doc_id 457083), accessed 2026-09-22
- Sony LDAC official site: comparison baseline of a 328 kbps SBC stream at 44.1 kHz (about 3x payload claim). sony.net/Products/LDAC/, accessed 2026-09-22
- SoundGuys, Bluetooth codec support for headphones: comparison table row (SBC 320kbps / 16-bit / 48kHz) and "iPhones only support the AAC and SBC Bluetooth codecs." soundguys.com/bluetooth-codec-support-headphones-61989/, accessed 2026-09-22
- SoundGuys, "Android's Bluetooth latency needs a serious overhaul": SBC 308 ms average across four Android phones; measured with a Bluetooth receiver and instrumentation, not headphones. soundguys.com/android-bluetooth-latency-22732/, accessed 2026-09-22
- RTINGS, "Test Bench 1.6: Latency R&D Article": "The average SBC latency of truly wireless earbuds is 259.8 ms. However, this is only obtained from five products, one of which is noticeably higher than the others."; AAC described as expected to be, at the minimum, as low latency as SBC. rtings.com/headphones/learn/research/latency, accessed 2026-09-22