The audio quality and the authenticity of real engines found in a soundset has more importance than some people may think at first because it can make the difference between a good and a must-have aircraft add-on.
Usable for the respective aircraft, you can purchase at simMarket :
- Engine Sound Creations – Airbus A340 CFM56-5C soundset FSX or FS2004
- Synchro-Soft 737NG V2 Soundset FSX or FS2004