Optimal settings for Bluetooth using LDAC in Android Oreo

[Moonflight]

I've got sweet Bluetooth IEM headphones (H2 from RBH) that support the new Sony "LDAC" Bluetooth codec that's available in Android Oreo (well, it's "somewhat" available -- my Samsung Galaxy S9 has LDAC available but only in Developer Options, which is fine and just needs to be reset upon a device restart).

I'm using Spotify's highest-quality downloads on my phone.

The questions is which of the following settings for Bluetooth are optimal with LDAC:

Bluetooth AVRCP version:

- 1.4 (Default)

- 1.5

- 1.6

Sample rate:

- 44.1

- 48

- 96

Bits per sample:

- 16

- 24

- 32

(Not to taint the discussion, but the head of the tech support dept for the maker of the headphones suggested I go with the highest available settings for Sample rate and for Bits per sample, 96/32, but he also seemed to be humbly suggesting he wasn't positive about that; and FWIW in my initial experimenting I don't know that anything above 44.1/24 or perhaps 48/24 is helpful and it seems the highest available settings may even be a bit distorted -- though I'm about as from an audiophile as it gets and my ear is not at all "trained.")

Thanks!

[Joe]

Hi. My understanding is that Spotify music is encoded with a frequency of 44.1KHz and 16 bits so using these values will avoid upscaling. The AVRCP version is only relevant when connecting to another media player and has no bearing on sound quality.

[Moonflight]

Thanks for this comment.

When I first asked the head of tech support at the maker of the Bluetooth headset about this, he wrote this back to me:

"I would set it to 32 bit, 96kHz. That is what the Google pixel 2 I have used with the H2 defaults to. The H2 appears to support the 32 bit just fine from what I have observed, though I haven't been able to verify that level of resolution is maintained through the entire audio path. The AKM DAC supports it but the Qualcomm 8675 digital output may not."

Then, when I informed him that the Spotify (and Tidal) downloads are 16/44.1 and I ran your comment past him (and said your advice seemed to make sense to me and even seemed to match my very untrained ears), he wrote this to me:

"Understood. I thought Tidal and Spotify were streaming in higher resolution. I still wonder how that applies to BT LDAC given it is still a lossy codec. Also, remember the AKM DAC is upsampling everything anyway to 32bit 384KHz.  Let your ears be your guide.  If what you hear is better at a lower resolution, so be it.  Let me know if you think that is the case."

I replied that I trusted "his" ears more than my own (and commented that I've spent way too much time trying to discern what's optimal in light of the fact that what I hear "varies" given my novice ears anyway), and said I trust "techs" like him and the forum.

Does the input from him mean anything in terms of what you'd suggest setting it to?

Thanks again!