Audio Renderer (audio device)
The Audio Renderer represents an audio device used to output audio from the computer to Speakers or an external Sound System. Each physical Audio Device (Sound Card or Integrated Audio) may have two or more Audio Renderers listed (output to speakers, headphones, S/PDIF, etc). By default, the Audio Renderer is set to "Default DirectSound Device", the primary audio renderer used by windows.

Under certain conditions (usually older, non-compatible audio devices) you may need to select a "WaveOut" based audio renderer to resolve audio glitches.

Please note,
Changing the audio volume level with a WaveOut device, changes the system volume level (DirectSound devices have no impact on the system volume level).

Audio Device Filter Manager
The Audio Device Filter Manager is an advanced feature used to view and modify an audio device's system priority (merit). There is very little reason to modify an audio device's priority as Zoom Player's Audio renderer selection overrides the system priority, use with care!

Preferred Stream Selection
Zoom Player can automatically activate Audio stream tracks in media files based on specified language identifiers such as "Language Country ID", Language name masks (partial language name supported) or a specific stream index number.

At first, Zoom Player attempts to match the Country ID (not all streams list a Country ID identifier). Failing that, Zoom Player tries to make a text match with a language name (not all streams list the language's name). Lastly, Zoom Player can set a specific stream index number. For example, if the media contains two audio streams, setting a Stream Number index of "0" enables the first audio track and a Stream Number index of "2" enables the third audio track.

Multiple language text matches can be specified by separating each language entry with the ";" character.
For example, by specifying "jap;eng", a "Japanese" language track is enabled when detected. When no "Japanese" language is detected, Zoom Player searches next for an "English" language track to enable.

Enable Internal DSP Filter (Equalizer / Audio Stream Switching / Audio Synchronization)
When enabled, Zoom Player uses its internal Audio DSP component (filter) to support such functions as Audio Equalizer, PreAmp (digital audio amplification) and Audio stream switching in media files. On very rare conditions, the DSP component may cause audio problems and can be disabled here.

Enable Equalizer / PreAmp (requires Internal DSP filter enabled)
This setting enables/disables the Zoom Player internal PreAmp/Equalizer features. The same action as the "ON" button on the Equalizer user interface.

Set Equalizer Range to +/- 20db (default is 12db)
By default, Zoom Player's Equalizer range (frequency range) is 12db, by enabling this setting, the range is extended to 20db, allowing for stronger amplification ranges while sacrificing a bit of user-interface sensitivity (less pixels representing a wider range).

Link volume up/down functions to PreAmp volume when increasing volume past 100%
This feature is specific to the "Volume Up" ("+" or "=" keys) and "Volume Down" ("-" key) functions. When enabled, increasing the audio volume level past 100% increases the Equalizer PreAmp levels (digital, lossy volume adjustment). Decreasing the volume levels first decrease the PreAmp value to its default level and only then the volume level is reduced, providing a wider volume range on demand (very useful when playing media with extremely low volume range).

Audio re-synchronization step accuracy (ms)
This field specifies the re-synchronize audio function's step size and accuracy in milliseconds.

Initial audio re-synchronization offset value when opening new media (ms)
In cases where audio is always out of synch by a fixed value (due to hardware constraints such as physical distance from speakers for example), this field specifies the default audio re-synchronization value set when opening a media file.