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How to apply special effects to a playing sound

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This control supports the following kinds of special effects:


Custom DSP effects


Vocal remover


DC Offset removal

VST effects

DirectX Media Object effects


EAX effects



Custom DSP effects


The purpose of custom DSP effects is to give the developer the possibility to apply custom DSP algorithms to the sound under playback. Check the How to manage custom DSP effects tutorial for further details.





You can apply or remove a filter (low pass, high pass, band pass or stop band) through the FilterApply and FilterReset methods.



Vocal remover


You can apply or remove the vocal remover filter through the FilterVocalRemoverApply and FilterVocalRemoverReset methods.





You can apply or remove normalization to a playing sound through the NormalizationEnable method.



DC Offset removal


You can enable or disable DC Offset removal to a playing sound through the DcOffsetRemovalEnable method.



VST effects


Steinberg''s Virtual Studio Technology (VST) is an interface for integrating software audio synthesizer and effect plugins with audio editors and hard-disk recording systems. VST and similar technologies use Digital Signal Processing (DSP) to simulate traditional recording studio hardware with software. Thousands of plugins exist and VST is supported by a large number of audio applications. Check the How to manage VST effects tutorial for further details.



DirectX Media Object effects


DirectX Media Objects (also known as DMO) are components that can be inserted in a media stream to manipulate the data in some way. In audio, DMOs are generally used to create special effects.

The use of DMO requires DirectX version 8 or higher: you can check if your system has the required DirectX version installed using the IsDirectX8Avail method.


The following standard effects are installed with the operating system:






Environmental reverberation (I3DL2)



Parametric equalizer

Waves reverberation (music reverb based on the Waves MaxxVerb technology, licensed to Microsoft)


These effects can be used with any sound format supported by our control and come with their own default settings: you can retrieve the current settings using the GetDirectXEffectParams and you can change them using the SetDirectXEffectParams . Once the effect parameters have been setup, you can apply/remove an effect using the SetDirectXEffect method; in case you should need to apply more effects at the same time, and you should need to apply them in a specific order, you could add them to the chain of effects with a certain priority through the SetDirectXEffectEx method.


Note that more than one DMO effect can be applied on a playing sound.





Sound equalization is obtained through the DMO effect "Parametric equalizer". Check the How to create and use an Equalizer tutorial for further details.



EAX effects


EAX environmental effects can be applied to a given output device (sound card) in order to enhance your music listening experience: not all of the commercial sound cards implement EAX and not all of the sound cards implementing EAX reach the same quality you can have with Creative sound cards. You can check if an output device supports EAX through a call to the IsEAXAvailableOnOutputDevice method.


EAX parameters (volume, decay and damping) applied to a given output device can be obtained through the GetEAXEffect method and changed through the SetEAXEffect and SetEAXEffectPresets methods. Differently from DMO effects, which are applied directly to an existing player, EAX parameters are applied to a given output device: this means that EAX settings will automatically affect all of the players associated to an EAX compatible output device.


At runtime it's easy to know if a given player is associated to an EAX compatible output device through the IsEAXAvailable method and obtain/modify the EAX wet/dry mix ratio for that specific player through the GetEAXEffectWetDryMix and SetEAXEffectWetDryMix methods.


It's important to note that EAX effects can be applied only to sounds loaded through the LoadSoundForEAX method: this method will load a given song in Mono and will not allow further Tempo, Playback rate and Pitch changes.


EAX supported effects are the following:


None (removes the current EAX effect, if any)


Padded cell



Living room

Stone room


Concert hall




Carpeted hallway


Stone corridor







Parking lot

Sewer pipe






It's important to note that EAX effects are mutually exclusive: you cannot have more than one EAX effect applied on an output device.



Samples of use of the mentioned special effects in Visual Basic 6 and Visual C++ 6 can be found inside the following samples installed with the product's setup package:

- SpecialEffects

- VstEffects

- CustomDSP

- CustomDSPWithUI

- TestEqualizer

- TestVideoPlayer