Audacity Forum

Hey Everybody,

I just recorded a Dj Mix at home and did record the whole mix in Audacity.


After 2 Hours and 3 minutes the Speed increases in the recording...
After 2 Hours and 56 min the Speed got back to normal

In this period the recording sounds distorted as well.

Before and after that pitch change the recording sounds perfect.

I do not remeber touching the Laptop in that time, luckily I was recording the set parallel with a tascam dr40 on Record-Out on my Mixer, so i have a working Mixfile, but i wonder what was the reason anyways.

Just saw that there is a newer version of audacity online, i will Update now from 2.2 to 2.4 and try again maybe another day.

Attached you see the waveform of the distorted time Area and a Soundfile which shows the beginning and the end of that strange behavior.

I´m thankful for any suggestions.

best regards
Richarde

Richarde wrote: ↑

Mon Feb 15, 2021 5:32 pm

After 2 Hours and 3 minutes the Speed increases in the recording...
After 2 Hours and 56 min the Speed got back to normal

So I was thinking that perhaps the sample rate somehow got bumped around...

I measured and found that the before the jump, the rate was about 122 BPM, then right after the speed increase it went to 146 BPM, a ratio of 5:6. The 44100Hz to 48000 Hz is more like 10:11, so it does NOT look like this is what happened.

I am not sure I would want to hazard a guess as to what might cause this. Do you think it could be the USB interface on your mixer?

Thanks for analyzing and taking time for this.

As it was the first time i used the soundinterface of the mixer and audacity for recording it could come from everywhere.

I was hoping someone could tell by the behaviour "ah, that´s this and that, i used to have the same Problem"...

I´m still hoping for this user and will meanwhile keep updates posted here.

ths Richarde