GOM Player 
GOM Encoder
Output Device
Sound card may work in two modes: DirectSound and WaveOut. If it is some problems when using filter
(for example if SPDIF does not work) it is possible that mode switch may help.
Normalizer
Used to get the same volume level.
Equalizer
Allows you to fine tune your audio playback by increasing or decreasing the volume within specific frequency ranges. In addition, you can use an equalizer preset.
Gain Control
Adjusts loudspeaker volume. It makes the quiet sounds louder and the loud sounds quieter. No more blasting one minute, too quiet the next.
AC3 Channel Setting
* For 5.1CH sound, you need a soundcard which supports 5.1CH; a speaker which supports 5.1CH; and you have to change GOM Player’s configuration as 5.1CH – go to the Preferences.
About the channel
1 CH: Has only 1 speaker
2 CH: Has Left and Right speakers – the most common speaker system
3 CH: Has Left, Right and Rear speakers
4 CH: Rear Left/Right and Front Left/Right speakers
5.1 CH(6-Piece): Has Central/Bass, Rear Left/Right, Front Left/Right speakers
* DSP Plugin (Voice Amplification Program)
When watching a video and the background sounds are loud but you cannot hear voices, the DSP Plugin will fix this situation.
You just have to select the folder that the DSP Plugin is located.
※ Voice Filter - Remove
Use Remove option, you may see a screen with background sound - without voice.
※ Voice Filter - Emphasize
Use Emphasize option, you can increase the voice of people (useful when background is louder than people’s voice).
※ Reverberation
Even though the sound stops, the reflections can continue. In this area, you can set a level, frequency, delay of Reverberation.
※ Extra-Stereo
Use Extra-Stereo, 3D sound makes you more similar to the real world.