ActiveX OCX to control the system mixer, with multi-soundcard support The OCX can control all the detected lines of a soundcard , and with support to multiples soundcard installed It will detect the following lines: Master Volume Wave Midi Microphone Line CD Analog Auxiliary Telephone Undefined Digital PC Speaker After the detection it will make it possible to retrieve and set these lines of the soundcard with only a few functions In order to set the Master Volume the following api will be used: RSPMixer1.SetMasterVolume DeviceID, Left, Right In this case the DeviceID is the identifier of the installed soundcard , Left is the value to the left channel ranging from 0 to 10 , Right is the value to the right channel After the call the system mixer will have the value modified In oder to retrieve the Master Volume the following api will be used: Ret = RSPMixer1.GetMasterVolume(DeviceID, Left, Right) In this case DeviceID is the identifier of the installed soundcard , Left is the variable that will receive the left channel value , Right is the variable that will receive the right channel value In order to get the mute state for the Master Volume the following api will be used: Ret = RSPMixer1.GetMasterMute(DeviceID, Value) In this case DeviceID is the identifier of the installed soundcard , Value is the variable that will receive the mute state of the Master Volume , it can be 0 or 1 , 0 to mute off , and 1 to mute on In order to set the mute state for the Master Volume the following api will be used: RSPMixer1.SetMasterMute DeviceID, Value In this case DeviceID is the identifier of the installed soundcard , Value is the new value to the mute state , 0 to mute off , and 1 to mute on