[Nexus 6 Themes and Apps] :
XTREMEMusic Revival / Remaster

So after a couple sleepless nights of listening for every nuance of each build.prop from the XTREMEMusic project (some of which have already been suggested by other users and myself) I offer my refined tweaks and some reflections here:

# Make sure below enabled / added if not present
dev.pm.dyn_samplingrate=1
tunnel.audio.encode=false
audio.offload.gapless.enabled=true
audio.offload.buffer.size.kb=256
audio.offload.video=true
audio.offload.pcm.16bit.enable=true
audio.offload.track.enabled=true
audio.offload.passthrough=false
audio.offload.multiple.enabled=false
audio.offload.pcm.24bit.enable=true
# This is a multiplier - 4 = 4x48000Hz = 192KHz
# M9 has this by default, v4.7 adds this to ViPER section.
# Use only one - I comment out duplicate default props so these take priority
af.resampler.quality=4
# These are default on M9 - add if not present
htc.audio.global.state=0
htc.audio.global.profile=0
htc.audio.q6.topology=0
htc.audio.global.speaker=1
#
## ViPERAudio ##
#
audio.deep_buffer.media=false
lpa.decode=false
tunnel.decode=false
tunnel.audiovideo.decode=false
lpa.releaselock=false
lpa.use-stagefright=false
persist.sys.media.use-awesome=1
# This is a multiplier - 4x48000Hz = 192KHz rate
persist.af.resampler.quality=4
# Separate from default resampling, use both
persist.dev.pm.dyn_samplingrate=1
# ALSA props for ViPERAudio 4.7
ro.sound.alsa=snd_pcm
AUDIODRIVER=alsa
ro.sound.driver=alsa
clock.allow_streaming_errors=false
# Changed this to "best" as XM project had it
default.pcm.rate_converter=samplerate_best

#
# XTREMEMusic Experimental Props #
#
audio.offload.track.enabled=true
# 16bit offload and track are required for DSEE
audio.offload.pcm.32bit.enable=true
# 32 and 64bit might have no effect but no issues
audio.offload.pcm.64bit.enable=true
# ALSA Mixer (Experimental - no issues yet)
alsa.mixer.playback.master=Speaker
alsa.mixer.capture.master=Mic
alsa.mixer.playback.earpiece=Earpiece
alsa.mixer.capture.earpiece=Mic
alsa.mixer.playback.headset=Headset
alsa.mixer.capture.headset=Mic
alsa.mixer.playback.speaker=Speaker
alsa.mixer.capture.speaker=Mic
alsa.mixer.playback.bt.sco=BTHeadset
alsa.mixer.capture.bt.sco=BTHeadset

# HTC/Beats/Boomsound/Dolby associated props
ro.config.hw_dolby=true
ro.config.hw_dts=true
htc.audio.swalt.enable=1
# Can go as high as 14512 - this is a smooth value
htc.audio.swalt.mingain=1920
persist.htc.audio.pcm.samplerate=192000
persist.htc.audio.pcm.channels=2
persist.audio.vr.enable=false
htc.audio.lpa.a2dp=0
htc.audio.alc.enable=1
persist.audio.SupportHTCHWAEC=1
# These may have no effect but create no issues
support_harman=true
support_boomsound_effect=true

# Sony Edition associated props
# This seems totally necessary for some of Sony's effects - adding it was an audible change
mpq.audio.decode=true
sony.support.effect=0x1FF
ro.semc.sound_effects_enabled=true
ro.semc.xloud.supported=true
persist.service.xloud.enable=1
com.sonyericsson.xloud_enabled=true
ro.semc.enhance.supported=true
persist.service.enhance.enable=1
ro.semc.clearaudio.supported=true
persist.service.clearaudio.enable=1
ro.somc.clearphase.supported=true
persist.service.clearphase.enable=1
com.sonymobile.clearphase_enabled=true
ro.somc.cp.default_setting=true
ro.somc.xloud.default_setting=true
ro.somc.sforce.supported=true
persist.service.sforce.enable=1
com.sonymobile.sforce_enabled=true
ro.somc.sfs.default_setting=true
ro.somc.dseehx.supported=true
ro.semc.dseehx.enable=1
persist.service.dseehx.enable=1
# Confirmed "semc"/"somc" are as on Xperia Z5P

# S Audio mod suggested props (from Xperia Z5P)
# SONY effect
# Allocate bit for each effect.
# If necessary, define effect list with logical sum.
# EFFECT_DN 0x0001 (Dynamic Normalizer)
# EFFECT_SF 0x0002 (S-Force)
# EFFECT_CPHP 0x0004 (ClearPhase Headphone)
# EFFECT_CA 0x0008 (ClearAudio)
# EFFECT_VPT 0x0010 (VPT)
# EFFECT_CPSP 0x0020 (ClearPhase Speaker)
# EFFECT_XLOUD 0x0040 (xLOUD)
# EFFECT_CAPLUS 0x0080 (ClearAudio+)
# EFFECT_SPBUNDLE 0x0100 (Speaker Bundle)
# EFFECT_ALC 0x0200 (ALC)

# Effect used by Speaker Bundle.
# EFFECT_SF | EFFECT_CPSP | EFFECT_SPBUNDLE = 0x122
sony.effect.custom.sp_bundle=0x122

# Effect used by ClearAudio+ headset
# EFFECT_CA | EFFECT_VPT | EFFECT_CAPLUS | EFFECT_ALC = 0x298
sony.effect.custom.caplus_hs=0x298

# Effect used by ClearAudio+ speaker
# EFFECT_CA | EFFECT_VPT | EFFECT_CPSP | EFFECT_CAPLUS | EFFECT_ALC = 0x2B8
sony.effect.custom.caplus_sp=0x2B8

# Noise reduction tweaks (Beta phase - seems working)
# These reduce in call noise by using dual mics
# Remove these if unsure if you have dual mics
htc.audio.enable_dmic=1
persist.audio.handset.mic=digital
# Legacy tweaks - these reduce noise noticeably
htc.audio.alt.enable=0
htc.audio.hac.enable=0

Do with this knowledge what you will. I offer no insight or support beyond that this setup is working flawlessly on my HTC One M9 with the ViPERAudio 4.6 Dark Sony Beats Edition (Permissive) I posted recently and the Lover of Sound Profiles I shared.

---------- Post added at 01:41 AM ---------- Previous post was at 01:35 AM ----------

Hey [MENTION=4445176]guitardedhero[/MENTION] just noticed this post after I made mine about the XM revival. As soon as you have a ViPERAudio Sony Beats 4.7 up I'll upload my Dark Permissive version and update that post to reflect the correct and working ALSA props.

--EDIT: I have revised and updated the build.prop section for v4.7 - users may want to copy the entire section starting with ViPERAudio and carefully paste over that section in build.prop. I also strongly recommend combing through default build.prop settings to make sure there are no conflicts or duplicates - this was totally necessary for me to achieve the glorious setup I have running as I type this.

I've also updated this post's attachments with ViPER|Audio™ 4.7 Dark Sony Beats Edition (Permissive) for users with Permissive Selinux only.