How do I set audio analysis (or other effect ) on master audio output ?

Unfortunately there is no "master channel" that you can add effects to and you cannot add multiple tags to audio.

Ok thanks for your answer. 🙂

I hope that one day Construct will support multiples audio tag and let apply fx on master output 🙏

As do I. You can create a tag management system using arrays that will achieve some of the things you want from multiple tags. If you want to look into that there are a few threads on these forums that have some good info.

Thanks for the tips, I'll give it a try !