@FernandoBadler @johnebaker @AAProds @Marc-Goder

Hi.

There is a marked difference in the way audio files are generally handled in a video editing application than a dedicated audio editor. A video editor has to load the audio and video data in 'chunks' to keep both audio and video in sync with each other. That often means that a sound wave gets chopped where the volume voltage is not zero. Where the voice coil of a speaker or headphone would naturally come to rest. You can hear that at the end of a clip that still has some sound running in it. The lower the frequency of a waveform is, the less amount of times it crosses the zero voltage line. If you have two channels on the same file with differing time differences the chances of both channels at once having the same zero point in the timeline at once diminish. This is less likely, the higher the frequency as a 40Hz wave has a travel distance of twenty eight feet per second compared to say a 5kHz has a travel distance of just under ten inches per second, so more chances of crossover points in the waveform the amount of higher frequencies that are present at the time.

Of course a digital waveform is a representation of all the frequencies present at once so you rarely get to see something representing a pure waveform.

Mixing two or more audio files together where there is a sudden drop or increase in the voltage results in a click at that point as the speaker coil rapidly responds to the difference producing a punch of air displacement. This is more likely to occur where there are more low frequencies present than high ones but can still often happen at a mix of higher frequencies. This explains the click we sometimes get to hear at the beginning or end of a clip. Even most silence has some background noise to it.

Below I have increased the view of a 40 to 50Hz waveform over a very short period of time.

You can just make out the digital steps in the waveform.

You can see the lack of edit points available. While there may be quite a few per 1/60s, the chance of the file being cut there is slim. A good audio editor will only cut on matching zero voltage points of a stereo file which will be very close to the point you select but hardly ever the exact point you select. At normal zoom levels you can't see the difference in length of the file. It's down to milliseconds. Most editors will not zoom to the levels I have above. It may have been easier to see if I had used a 16 bit file rather than a 32 bit file. Lets look at how far in I actually zoomed.

Towards the end of each play-through, you can see the lower frequencies dominate and the amount of possible edit points move further apart.

And now, lets zoom out time wise.

The problem about the repeated clicks / distortion we hear from trying to use the same file in quick succession though is different and again may be associated with the audio having to be loaded in chunks. The same file in the same position is meaning a reading and loading of the same data twice into ram from the same data storage point and I think this causes some sort of parity problem where the data being loaded is not for whatever reason able to be checked accurately and possibly loaded in the wrong order. Of that I'm not sure but it is what it sounds like when played. Having at least one file in a different location alleviates that problem. This may be a problem for most video editors. It may depend on how large each data chunk being used is. All I know for sure is that it exists in these video editing programs and not with audio editors in general which tend to use much larger amounts of data from a file at a time. Probably they are able to do that because they do not have to process video at the same time. The problem may even be curable. For that it would be best to raise a ticket with Magix.

Ray.