The File Extension .SDX is used for the file type called Sample MIDI Dump Exchange File. (See References 1) Sample MIDI Dump Exchange files are categorized into the audio files. (See References 1)
Applications that open the .SDX files are Apple QuickTime Player and Awave Studio. (See References 1)
The purpose of .SDX file is to transfer the sound from one device to another. The devices should be MIDI-enabled. (See References 2)
MIDI is the short name for Musical Instrument Digital Interface.
If your computer can not open the SDX file, you might not have installed the required program, or you may have registry errors in your Windows operating system. (See References 3)
There are other files that use the SDX extension. These files are CaptiveWorks Satellite Channel Database, Sample Sound File, and Smart Diary Suite temporary file. (See References 3)