When you’re using multiple music tracks in your slideshows, especially ones from different sources, chances are that certain tracks are noticeably louder than others. There are two things at play here: amplitude and dynamic range. Changing the track volume in ProShow Gold or ProShow Producer only addresses the amplitude. To address differences in perceived loudness, you’ll occasionally need to alter the dynamic range in a 3rd party program. Today I’ll give a few tips on how to do this.
When people talk about the volume of a track, they often are referring to the peak amplitude, or essentially the loudest point of a track. Most tracks on a well-mastered CD will have their peak amplitude somewhere close to 0 decibels (all quieter parts will have a negative decibel value). Increasing the volume of a well-mastered track will often push it over the limit in several places and introduce digital distortion (a.k.a. “clipping”). For this reason, it should be relatively uncommon that you ever set the track volume in ProShow to something above 100%. When in doubt, lower the volume of a “loud” track instead of raising the volumes of the comparatively quiet tracks.
Some songs start off quiet and end loud. Others have quiet and loud parts interspersed. And sometimes, a track is just loud the whole time. In a very basic way, these qualities describe the dynamic range of a song. What happens when one song ends loudly and you segue into a song that starts quietly? This is the type of thing that can cause a viewer to scramble for the remote control or volume dial.
Fortunately, you can alter the dynamic range of a track so that the highs and lows aren’t so extreme, and by extension, the transitions between tracks aren’t so extreme. Of course, it’s possible to overdo it (Top 40 radio stations come to mind) but dynamic range compression can be a very important tool when applied with care. I’ll show you how you can do this in the free audio editor Audacity:
- Download the Audacity installer here, then run through the installation process afterward.
- Run Audacity, then go to File > Open and select your track.
- Under the Effect menu at the top, choose Compressor. Check Compress based on Peaks at the bottom of the window. The rest of the settings should be fine at their defaults, but you can lower the Threshold and increase the Ratio for more extreme scenarios. Click OK.
- Go to File > Export, then save the edited track somewhere. Make sure to not overwrite the original track. This will save as a .WAV file by default which may be somewhat large, but this ensures that you don’t lose any additional fidelity when editing in Audacity.
If you’ve done this to each track prior to importing them into ProShow, there’s a good chance that you won’t have to touch the Track Volume option at all once they’re imported.
- Most audio editors will allow you to achieve the same goal, perhaps with even more options and precision. Just look for a Compression / Dynamics Processing feature, which will allow you to reduce the dynamics of the track.
- If you’d like to maintain the original dynamics of your tracks but make sure their peak volumes are all the same, you can use the Normalize feature in Audacity’s Effect menu (this is also found in most other audio editors) and specify a peak volume. Normalizing to 0 decibels (or 100%) should be fine.