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Is there no setup for unidirectional Bluetooth to improve bandwidth?
I believe AptX is the best quality codec but I don't think that means it's unidirectional.

In practice I think you'd still want a little bit of bandwidth going the other way in order to be able to skip tracks/pause/etc.

This seems worse than aptX Voice, which has a 32 kHz sampling rate, and which many devices already support.
Apples codec is for the hands free profile (synchronous mode). Are you saying aptX works with that?
AptX Voice does, yes. But Apple doesn't like paying Qualcomm licensing money.
If that means not losing support of the device 5 minutes after I bought it because Qualcomm and Apple can’t come to an agreement I rather have lower quality during calls.
> These have a fixed data rate of 64 kbit/s (bidirectional). You can see that, at that bitrate, even a sophisticated codec, like AAC, will be limited in quality.

It needs a little more explaining. It is 64kbps while keeping it extremely low latency that makes it difficult. AAC-ELD has a coding delay down to 7.5 ms at a sampling rate of 48 kHz.

Considering they have to paid for AAC-ELD and EVS, I wonder why they didn't choose EVS over AAC-ELD, or Opus.

I think audio codec is mostly a solved problem for music, the next frontier is how do we get sub 5ms latency to sound exceptionally good with 64kbps only.

Can confirm, AirPods Pro deliver 24k audio to the mac now.

(A cheapest external lavalier microphone still sounds so much better than that.)