[Teclast X98 Air 3G] Frontier:
I think you are right; this file looks like the one that [MENTION=1066120]xcoom[/MENTION] mentions below.

Will extract this from both Android ROMs and compare.

Stay tuned.

Thanks, this file is missing from the X98 Air 3G Android install but the file that [MENTION=6048136]HDtracer[/MENTION] above mentions is pretty similar to this.

Edit: AudioConfigurableDomains.xml file is 100% the same between 4.4.2 and 4.4.4, the critical session could be this

<ConfigurableElements>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/STEREO/VOLUME/0/LEVEL"/>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/STEREO/VOLUME/1/LEVEL"/>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/MONO/VOLUME"/>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/ANALOG/3/BOOST_GAIN"/>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/ANALOG/2/BOOST_GAIN"/>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/STEREO/BOOST_GAIN"/>
</ConfigurableElements>
<Settings>
<Configuration Name="VoiceRecgnition.FrontMic">
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/STEREO/VOLUME/0/LEVEL">
<IntegerParameter Name="LEVEL">112</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/STEREO/VOLUME/1/LEVEL">
<IntegerParameter Name="LEVEL">112</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/ANALOG/3/BOOST_GAIN">
<IntegerParameter Name="BOOST_GAIN">5</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/STEREO/BOOST_GAIN">
<IntegerParameter Name="BOOST_GAIN">1 1</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/MONO/VOLUME">
<IntegerParameter Name="VOLUME">80 80</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/ANALOG/2/BOOST_GAIN">
<IntegerParameter Name="BOOST_GAIN">5</IntegerParameter>
</ConfigurableElement>
</Configuration>
<Configuration Name="FrontMic">
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/STEREO/VOLUME/0/LEVEL">
<IntegerParameter Name="LEVEL">127</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/STEREO/VOLUME/1/LEVEL">
<IntegerParameter Name="LEVEL">127</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/ANALOG/3/BOOST_GAIN">
<IntegerParameter Name="BOOST_GAIN">1</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/STEREO/BOOST_GAIN">
<IntegerParameter Name="BOOST_GAIN">1 1</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/MONO/VOLUME">
<IntegerParameter Name="VOLUME">80 80</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/ANALOG/2/BOOST_GAIN">
<IntegerParameter Name="BOOST_GAIN">5</IntegerParameter>
</ConfigurableElement>
</Configuration>
<Configuration Name="HeadsetMic">
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/STEREO/VOLUME/0/LEVEL">
<IntegerParameter Name="LEVEL">111</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/STEREO/VOLUME/1/LEVEL">
<IntegerParameter Name="LEVEL">111</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/ANALOG/2/BOOST_GAIN">
<IntegerParameter Name="BOOST_GAIN">5</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/STEREO/BOOST_GAIN">
<IntegerParameter Name="BOOST_GAIN">1 1</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/MONO/VOLUME">
<IntegerParameter Name="VOLUME">80 80</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/ANALOG/3/BOOST_GAIN">
<IntegerParameter Name="BOOST_GAIN">5</IntegerParameter>
</ConfigurableElement>
</Configuration>
<Configuration Name="InCall.FrontMic">
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/MONO/VOLUME">
<IntegerParameter Name="VOLUME">80 80</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/ANALOG/3/BOOST_GAIN">
<IntegerParameter Name="BOOST_GAIN">1</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/STEREO/VOLUME/0/LEVEL">
<IntegerParameter Name="LEVEL">112</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/STEREO/VOLUME/1/LEVEL">
<IntegerParameter Name="LEVEL">112</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/ANALOG/2/BOOST_GAIN">
<IntegerParameter Name="BOOST_GAIN">5</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/STEREO/BOOST_GAIN">
<IntegerParameter Name="BOOST_GAIN">1 1</IntegerParameter>
</ConfigurableElement>
</Configuration>
<Configuration Name="InCall.HeadsetMic">
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/MONO/VOLUME">
<IntegerParameter Name="VOLUME">100 100</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/ANALOG/2/BOOST_GAIN">
<IntegerParameter Name="BOOST_GAIN">2</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/STEREO/VOLUME/0/LEVEL">
<IntegerParameter Name="LEVEL">112</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/STEREO/VOLUME/1/LEVEL">
<IntegerParameter Name="LEVEL">112</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/ANALOG/3/BOOST_GAIN">
<IntegerParameter Name="BOOST_GAIN">5</IntegerParameter>
</ConfigurableElement>
<ConfigurableElement Path="/Audio/REALTEK/SOUND_CARD/INPUT/DIGITAL/STEREO/BOOST_GAIN">
<IntegerParameter Name="BOOST_GAIN">1 1</IntegerParameter>
</ConfigurableElement>
</Configuration>
</Settings>
</ConfigurableDomain>

Using from alsa_amixer -c 0 from a Terminal su session, the values are consistent (i.e the microphone gain /Audio/REALTEK/SOUND_CARD/INPUT/ANALOG/3/BOOST_GAIN is 5 on both ROMs) so the issue is not there (probably). I've played with these values, using the commands (on a su Terminal session):

alsa_amixer -c 0 set "IN2 Boost" 0
alsa_amixer -c 0 set "IN3 Boost" 0

and this made Google Now able to recognize SOME words (i.e traffic, weather) on some occasions but it's not enough.

There are also some values regarding volume that look way too high (112, 100 etc) but I am troubled that they are exactly the same on the 4.4.2 file where Google Now recognizes words.