Classic Bluetooth (A2DP) is the universal default and the source of most lip‑sync pain: compressed stereo over SBC or AAC, with an encode–transmit–buffer–decode pipeline that routinely runs 150–250 ms, and no real multichannel or high‑res story.
Bluetooth LE Audio (LC3) is the genuine step forward, built on the Isochronous Channels added in the Bluetooth 5.2 feature set. It cuts latency to the 20–30 ms range, carries a defined presentation‑delay timestamp so multiple sinks render in step, and adds multi‑stream and broadcast (Auracast). For earbuds, headphones and simple multi‑speaker setups it closes most of the old gap. Its ceiling is bandwidth and range.
Buffered Wi‑Fi streaming (Sonos, AirPlay, Chromecast) is the inverse profile: enormous bandwidth, excellent fidelity, rock‑solid multi‑room sync and whole‑home range — but a deliberate buffer that adds hundreds of milliseconds. Superb for music; wrong for anything tied to a picture, unless the video source itself is doing the streaming and can hold the picture back.
Real‑time (tweaked) Wi‑Fi — the WiSA‑class approach — is a Wi‑Fi‑band radio run in a proprietary low‑latency mode: scheduled airtime instead of best‑effort contention, tight cross‑device time sync, a lean real‑time transport and uncompressed multichannel PCM. Latency in the single‑digit milliseconds, speakers locked to each other and to the screen. It is the only one of the four that satisfies the full real‑time, high‑fidelity, room‑scale requirement at once.
The bandwidth gap is easy to quantify. Uncompressed stereo is about 1.4 Mbps at CD quality and 4.6 Mbps at 24‑bit/96 kHz; a 5.1 mix at 24/96 is roughly 14 Mbps and 7.1 around 18 Mbps. Bluetooth LE carries about 2 Mbps on its radio, and even an efficient codec like LC3 sits far below that, so high‑resolution multichannel is a Wi‑Fi job by arithmetic alone. Which is the same point from the other side: once you are on Wi‑Fi, bandwidth stops being the constraint and timing becomes the whole job.