Video with movie clips in it has low volume on Youtube

[Moviegeek237]

I edited my recorded video clips together with short clips from movies in Videopad (I converted these movie clips from DVDs to MP4 with a video converter. )

The uploaded video on Youtube had less than half the volume with these clips in it than without them (I tested it with a version without the movie clips and the volume of my recordings on Youtube is OK.) So there must be a problem with the sound of these movie clips. At first I tried to amplify the complete volume of the video but there was a loud whooshing background noise and the volume of the uploaded video was still low.

I even tried to reduce the volume of these movie clips with Wavepad (the sound editor-mixer of Videopad) because I heard in a tutorial that Youtube reduces the volume of the whole video if parts of it are too loud. The result was just the same or even worse:  the overall volume of the uploaded video on Youtube with the movie clips in it was still very low (I tested it several times) and the sound of the movie clips with reduced volume were strangely distorted.

I understand of course that the sound of a movie clip with dialogue and music/background noise is way more complex than the sound of my own recordings with my microphone but there has to be a way to solve this problem. What shall I do?