Sony HT-ST9 Manuel D'instructions page 24

 [SBM] (Super Bit Mapping)
[On]: Smooths the gradation of video signals output from the HDMI
OUT (ARC) jack.
[Off]: Select this if video signals are distorted or color is unnatural.
[Audio Settings]
 [DSEE HX]
This function is only available when [Music] is selected as the sound
field.
[On]: Upscales the audio file to a High-Resolution Audio file and
reproduces the clear high-range sound which is often lost (page 10).
[Off]: Off
 [Audio DRC]
You can compress the dynamic range of the sound track.
[Auto]: Automatically compresses sound encoded in Dolby TrueHD.
[On]: The system reproduces the sound track with the kind of
dynamic range that the recording engineer intended.
[Off]: No compression of dynamic range.
 [Attenuation settings - Analog]
Distortion may occur when you listen to a device connected to the
ANALOG IN jacks. You can prevent distortion by attenuating the
input level on the system.
[On]: Attenuates the input level. The output level will decrease at this
setting.
[Off]: Normal input level.
 [Audio Output]
You can select the output method used for audio signal output.
[Speaker]: Outputs multi-channel sound from the system's speakers
only.
[Speaker + HDMI]: Outputs multi-channel sound from the system's
speakers and 2-channel linear PCM signals from the HDMI OUT (ARC)
jack.
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[HDMI]: Outputs sound from the HDMI OUT (ARC) jack only. Sound
format depends on the connected device.
Note
When [Control for HDMI] is set to [On] (page 25), [Audio Output] is set to
[Speaker + HDMI] automatically and this setting cannot be changed.
[Bluetooth Settings]
 [Bluetooth Mode]
You can enjoy content from a BLUETOOTH device by using this
system or listen to sound from this system by using BLUETOOTH
receiver such as headphones.
[Receiver]: This system is in receiver mode, which enables it to
receive and output audio from the BLUETOOTH device.
[Transmitter]: This system is in transmitter mode, which enables it to
send audio to the BLUETOOTH receiver. If you switch the input of the
system, [BT TX] appears on the front panel display.
[Off]: The BLUETOOTH function is turned off and you cannot select
the [Bluetooth Audio] input.
Note
BLUETOOTH
You can connect to a
function even if you have set [Bluetooth Mode] to [Off].
 [Device List]
Displays a list of paired and detected BLUETOOTH devices (SNK
device) when [Bluetooth Mode] is set to [Transmitter].
 [Bluetooth Standby]
You can set the [Bluetooth Standby] so that the system can be
turned on by a BLUETOOTH device even when the system is in
standby mode. This function is only available when you set
[Bluetooth Mode] to [Receiver] or [Transmitter].
[On]: The system turns on automatically when you establish a
BLUETOOTH connection from a paired BLUETOOTH device.
[Off]: Off
device by using the One-touch