[Xperia Z Q&A, Help & Troubleshooting] s107ken:
miracast audio transfer affected by r_submix settings in audio_policy.conf, so refer to other devices settings.

Miracast Officially Supported Devices

Nexus 4 - https://android.googlesource.com/device/lge/mako/+/android-4.4.2_r1/audio_policy.conf

r_submix {
outputs {
submix {
sampling_rates 48000
channel_masks AUDIO_CHANNEL_OUT_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_OUT_REMOTE_SUBMIX
}
}
inputs {
submix {
sampling_rates 48000
channel_masks AUDIO_CHANNEL_IN_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_IN_REMOTE_SUBMIX
}
}
}

Nexus 5 - https://android.googlesource.com/device/lge/hammerhead/+/android-4.4.2_r1/audio_policy.conf

r_submix {
outputs {
submix {
sampling_rates 48000
channel_masks AUDIO_CHANNEL_OUT_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_OUT_REMOTE_SUBMIX
}
}
inputs {
submix {
sampling_rates 48000
channel_masks AUDIO_CHANNEL_IN_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_IN_REMOTE_SUBMIX
}
}
}

Nexus 7 2013 - https://android.googlesource.com/device/asus/flo/+/android-4.4.2_r1/audio_policy.conf

}
r_submix {
outputs {
submix {
sampling_rates 48000
channel_masks AUDIO_CHANNEL_OUT_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_OUT_REMOTE_SUBMIX
}
}
inputs {
submix {
sampling_rates 48000
channel_masks AUDIO_CHANNEL_IN_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_IN_REMOTE_SUBMIX
}
}
}

Nexus 10 - https://android.googlesource.com/device/samsung/manta/+/android-4.4.2_r1/audio_policy.conf

r_submix {
outputs {
submix {
sampling_rates 48000
channel_masks AUDIO_CHANNEL_OUT_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_OUT_REMOTE_SUBMIX
}
}
inputs {
submix {
sampling_rates 48000
channel_masks AUDIO_CHANNEL_IN_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_IN_REMOTE_SUBMIX
}
}
}

Miracast un-Officially Supported Devices

Galaxy Nexus - local repository

see http://xdaforums.com/showthread.php?t=2540694

r_submix {
outputs {
submix {
sampling_rates 48000
channel_masks AUDIO_CHANNEL_OUT_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_OUT_REMOTE_SUBMIX
}
}
inputs {
submix {
sampling_rates 48000
channel_masks AUDIO_CHANNEL_IN_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_IN_REMOTE_SUBMIX
}
}
}

Nexus 7 2012 - https://android.googlesource.com/device/asus/grouper/+/android-4.4.2_r1/audio_policy.conf

see http://xdaforums.com/showthread.php?t=2515833

r_submix {
outputs {
submix {
sampling_rates 48000
channel_masks AUDIO_CHANNEL_OUT_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_OUT_REMOTE_SUBMIX
}
}
inputs {
submix {
sampling_rates 48000
channel_masks AUDIO_CHANNEL_IN_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_IN_REMOTE_SUBMIX
}
}
}

All devices uses same settings.

Xperia

r_submix {
outputs {
submix {
sampling_rates 44100|48000
channel_masks AUDIO_CHANNEL_OUT_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_OUT_REMOTE_SUBMIX
}
}
inputs {
submix {
sampling_rates 44100|48000
channel_masks AUDIO_CHANNEL_IN_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_IN_REMOTE_SUBMIX
}
}
}

44100 deleted is proper :confused:

r_submix {
outputs {
submix {
sampling_rates 48000
channel_masks AUDIO_CHANNEL_OUT_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_OUT_REMOTE_SUBMIX
}
}
inputs {
submix {
sampling_rates 48000
channel_masks AUDIO_CHANNEL_IN_STEREO
formats AUDIO_FORMAT_PCM_16_BIT
devices AUDIO_DEVICE_IN_REMOTE_SUBMIX
}
}
}