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oritrontoday at 5:13 PM1 replyview on HN

Low latency in Bluetooth audio comes down to codecs and the best are proprietary.

If you want to really cut down latency and need wireless with hardware like this, you could use a second ESP32 and send your own bitstream between them.


Replies

timothyb89today at 6:20 PM

I've been experimenting with more-or-less this on the existing ESP32-S3 (well, to a smartphone/PC rather than a 2nd ESP32).

Practical bandwidth limits are in the ~72kb/s range with Bluetooth and a custom wire protocol, and Opus voice-mode encoding can't run in realtime beyond complexity 3; music encoding can't run at all. Maybe there's a more compute-friendly audio codec I'm not aware of, but as far as I know these chips just aren't quite powerful enough for high-quality music encoding, unfortunately. I'm hoping the S31 might be a bit better fit here (decent CPU boost + better SIMD).

Latency is still a bit rough with BT overhead. There might be some new options with LE audio on the S31 but I haven't found a way to get below ~80ms with the existing ESP32-S3 stack.

tl;dr, high quality voice is doable today with okay latency, music probably less so, maybe the S31 will be better