01-20-2023, 11:49 PM
Does anyone know how UAPP in a Pixel 7 Pro handles 88.2 kHz or 44.1 kHz audio files while streaming to a BlueTooth 5.0 device via LDAC? I just want to know the UAPP/Pixel 7 Pro combo handles/manipulates the audio before it's transmitted to my bluetooth device (AudioTechnica M50xbt2). Specifically, if the combo is able to stream at 44.1 kHz (integer multiple of 88.2 kHz) or does it upsample to 48 kHz?
According to the specs, the frequency Range of the AudioTechnica M50xbt2 are:
20 to 40,000 Hz (when LDAC 96 kHz sampling, 990 kbps)
20 to 20,000 Hz (when 44.1 kHz sampling).
The M50xbt2 uses an AK4331 audio DAC.
I've found out via Bluetooth Tweaker that the M50xbt2 (AK4331 DAC) supports the following codecs and sample rates:
[CODEC#1 supported by device]
CODEC Type: SBC, Sampling Frequency: 16/32/44.1/48kHz, Channel Mode: Mono/Dual Channel/Stereo/Joint Stereo, Block Length: 4/8/12/16, Subbands: 4/8, Allocation Method: SNR/Loudness, Min/Max Bitpool: 2/53
[CODEC#2 supported by device]
CODEC Type: MPEG-2, 4 AAC, Object Type: MPEG-2 AAC LC/[MPEG-4 AAC LC]/, Sampling Frequency: 44.1/48/kHz, Channels: 1/2, VBR: supported, Bit rate: 0
[CODEC#3 supported by device]
CODEC Type: LDAC, Sampling Frequency: 44.1/48/88.2/96 kHz, Channel Mode: Mono/Stereo/Dual
FYI it appears that Windows 11 only supports the following via Bluetooth:
CODEC Type: MPEG-2, 4 AAC, Object Type: MPEG-2 AAC LC, Sampling Frequency: 48kHz, Channels: 2, VBR: supported, Bit rate: 256,000.
So it appears that under my Windows 11 scenario (Intel AX200 WiFi), any audio file sampled at 44.1 kHz (or multiple) will get resampled to 48 kHz before it's streamed over to my headphones (via MPEG-2).
As I said, just want to know what's going on with 44.1 kHz type files in a Pixel 7 Pro/UAPP combo via LDAC.
According to the specs, the frequency Range of the AudioTechnica M50xbt2 are:
20 to 40,000 Hz (when LDAC 96 kHz sampling, 990 kbps)
20 to 20,000 Hz (when 44.1 kHz sampling).
The M50xbt2 uses an AK4331 audio DAC.
I've found out via Bluetooth Tweaker that the M50xbt2 (AK4331 DAC) supports the following codecs and sample rates:
[CODEC#1 supported by device]
CODEC Type: SBC, Sampling Frequency: 16/32/44.1/48kHz, Channel Mode: Mono/Dual Channel/Stereo/Joint Stereo, Block Length: 4/8/12/16, Subbands: 4/8, Allocation Method: SNR/Loudness, Min/Max Bitpool: 2/53
[CODEC#2 supported by device]
CODEC Type: MPEG-2, 4 AAC, Object Type: MPEG-2 AAC LC/[MPEG-4 AAC LC]/, Sampling Frequency: 44.1/48/kHz, Channels: 1/2, VBR: supported, Bit rate: 0
[CODEC#3 supported by device]
CODEC Type: LDAC, Sampling Frequency: 44.1/48/88.2/96 kHz, Channel Mode: Mono/Stereo/Dual
FYI it appears that Windows 11 only supports the following via Bluetooth:
CODEC Type: MPEG-2, 4 AAC, Object Type: MPEG-2 AAC LC, Sampling Frequency: 48kHz, Channels: 2, VBR: supported, Bit rate: 256,000.
So it appears that under my Windows 11 scenario (Intel AX200 WiFi), any audio file sampled at 44.1 kHz (or multiple) will get resampled to 48 kHz before it's streamed over to my headphones (via MPEG-2).
As I said, just want to know what's going on with 44.1 kHz type files in a Pixel 7 Pro/UAPP combo via LDAC.