10 Replies Latest reply on Jul 6, 2008 4:40 AM by (Andreas_E)

    Noise with multiple sounds

      When playing multiple sounds at the same time through ram preview, everything is fine. However, if I export such a composition, the sound will be all noisy and messed up.

      Example of how it sounds inside after effects:
      http://web.telia.com/~u87309837/Comp%201b.wav

      And after exporting:
      http://web.telia.com/~u87309837/Comp%201.rar



      I'm running After Effects 6.5.
      Any ideas?

      I tried putting the sounds in Premiere (1.5) and exporting, and that was just fine. Unfortunatly, I also want to use time remapping, and premiere doesn't have that feature.

      Thanks
        • 1. Re: Noise with multiple sounds
          Ko Maruyama User Group Manager
          What sample rate are you exporting it at?
          • 2. Re: Noise with multiple sounds
            Level 1
            I've tried all there are. Same issue. This one i think is 32KHz or 44KHz.
            • 3. Re: Noise with multiple sounds
              Level 1
              With three overlapping sounds, how high are you hitting on total volume? There's a cumulative effect when stacking up audio. Have you tried pulling the volume equally on all three?
              • 4. Re: Noise with multiple sounds
                Level 1
                Yes that will work. However, I want the sound to be that high. It seems, as I said, to work in premiere. Why wont it work in after effects? Now i have to change the volume of the music, for example, to avoid this. Is it really supposed to be this way?
                • 5. Re: Noise with multiple sounds
                  Level 1
                  Do you not have any audio software to mix down in? After Effects isn't too flexible with audio. Are you going to take the remapped shot back into Premiere? You could bring the volume back up there. I'm not sure what your workflow is, so it's hard to give any advice.

                  -s
                  • 6. Re: Noise with multiple sounds
                    Level 1
                    Basically I just want to be able to use time remap or equivalent on audio. I dont know any other software that can do it. After Effects would've been a good choice if it wouldnt mess it up when exporting, since I will be editing video aswell (that will be synced to audio). If you know some other, let me know. :)
                    • 7. Re: Noise with multiple sounds
                      Andrew Yoole MVP & Adobe Community Professional
                      Are the file mp3? AE 6.5 cannot use mp3 files properly - convert to an uncompressed format (aiff, wav) before import.

                      Watch the audio pallet during preview - is the audio clipping (hitting red)? If so, reduce the levels of each layer until it does not clip.

                      Try using the Render Queue (Make Movie) rather than Export.

                      Audacity is a Windows-based freeware audio editing application that has time stretching ability.
                      • 8. Re: Noise with multiple sounds
                        Level 1
                        So why not turn it down in AE and turn it back up in Premiere? Not ideal but should work fine. Or why not time remap the three files separately and then stack them in Premiere?
                        • 9. Re: Noise with multiple sounds
                          Mylenium Most Valuable Participant
                          >However, I want the sound to be that high. It seems, as I said, to work
                          >in premiere. Why wont it work in after effects? Now i have to change
                          >the volume of the music, for example, to avoid this. Is it really
                          >supposed to be this way?

                          Please read up on audio processing. The perceived loudness of an audio mix has in large parts nothing to do with the actual level of the separate files. Insisting on them being full volume will never get correct results, even less in a program like AE that only does linear mixing and resampling and does not figure in some of the logarithmic specifics of sound, does not provide functions for interpolating missing samples nor compensates for pitch and shift, which is what happens when you time-remap.

                          It would also be interesting to know how you generated the files in the first place - they may already contain clipped samples and other garbage that skews the results.

                          The whole matter is further complicated by embedded audio in video files needing to follow certain rules about reference levels - just like the video may need broadcast-safe colors, the audio needs a reference level which can be anything from -18 dB to +3dB. If it is not obbeyed, the audio will get clipped.

                          Therefore the files need to be normalized in the context of the final mix volume, which apparently is what AE does not, but Premiere and dedicated audio programs do. So unless you are willing to do the math all yourself and manually adjust the levels in AE so they perfectly level out after the mixdown, it sounds more logical in a program that is tailored to do that much better.

                          Obviously this will require some work and you will not be able to do much with your old versions of your programs. As a minor, you should give the free Audacity a spin which allows some time-stretching trickery. Beyond that you will certainly require a commercial sequencing program such as Cubase, Audition or whatever that allow you to load in video and sound for synchronous treatment. As a minor, if you really are stuck with your minimalistic combo of AE and Premiere, use Audacity to double the sampling rate of your source files to 96kHz At least it does some audio antialiasing and the resampled files should behave a tiny bit better when remapping them in AE.

                          Mylenium
                          • 10. Re: Noise with multiple sounds
                            Level 1
                            @Andrew Yoole
                            No they're wave.
                            Wow I didnt know about make movie and render queue. When I used it the sound didn't come along though. I couldn't find any settings to change if it would be exported or not.

                            @Steven Mullins
                            It would of course work, but the question is if it's the ideal way of doing it. I'm going to use this technique alot in the movie I'm going to make, so a quick workflow with good results is needed. :)

                            @Mylenium
                            I didn't realize it was this complex.

                            I'm going to check out Audacity now.