.EFV File

.efv is Ensoniq VFX-SD File

Key Features: .EFV File Extension

Sound format used by the Ensoniq VFX-SD digital workstation synthesizer

Associate the EFV file extension with the correct application. On :
Windows: Right click on any EFV file and then click "Open with" > "Choose another app". Now select another program and check the box "Always use this app to open *.EFV files". Mac: Right click (or Ctrl-click) the EFV file, then click "Open with" > "Other...". Then choose another program and check the "Always Open With" box. Linux: Right click on the file, and select "Open with" and choose another program. iPhone: Tap the file. If you do not see an app to open the file, then tap Share "Share" and choose an app. Alternatively, save the file. Then open the Files app Files app. There long-press on the file, then release your finger. You will see a black menu bar. Then tap "Share" and select an app. Android: Tap the Settings icon on your smartphone, then tap on the Apps section. There tap the Options icon in the top right-hand corner of the screen to change the default apps.
Update your software that should actually open .EFV is Ensoniq VFX-SD File. Because only the current version supports the latest EFV file format. Search, therefore, e.g. on the N/A manufacturer website after an available .EFV is Ensoniq VFX-SD File update.
To make sure that your EFV file is not corrupted or virus-infected, get the file again and scan it with antivirus software.