I render my AE project using Media Encoder, but when I check the output, its audio level clearly changes and go up at some parts and down on other parts! and its not consistent at all.
The thing is that sound doesn't have any problem. I check sound in Audition and its good, I even check the sound in AE and it doesn't have any problem on RAM preview.
Have you export the audio only from audition & does it have the problem then ?
Does the audio have a compressor on it? You could use one to keep the levels consistent.
Are you sending from AE to encoder with the sound file ? Try using premier as a middle man. Bring the AE sequence & Audition project into premier and export from there. Could be that AE is ignoring your mix because it’s AE. Alternatively you could export direct from AE the vision and the audio only from audition and stick the two together in premier.
If the source material is in stereo, but you are rendering any part of the chain in mono, it could be a stereo phasing issue. Maybe some sections of the audio track are in phase and others out of phase? Make sure everything is in stereo, and that the left channels are panned left, the right channels are panned right throughout.
If you mix out-of-phase stereo audio down to mono, it will cancel itself out, resulting in lower output, or sometimes no output.