Waveform diminishes After 1 1/2 hours of recording

Audacity 2.1.2
Windows 10, 64 bit

Audio Software: Audacity 2.1.2
Audio Interface: Scarlett 2i2
High Pass Filter: Shure A15HP
Mic: Blue Spark
Acoustic Treatment: Kaotica Eye Ball

After recording for 1 1/2 hours, the waveform diminished. I changed out the Mic cable and removed High Pass Filter. Is there a setting I could have changed the created this result?

I changed out the Mic cable and removed High Pass Filter.

You probably didn’t need to do that.

Any reason you used the Line connection instead of the USB? Or did you use the USB and I just can’t see the messages right.

There’s at least two things wrong this this shoot. Both blue waves are wrong. Nobody announces with waves neatly trimmed, perfectly evenly top and bottom like that. As near as I can tell, the second waves are normal, just not high enough. It’s my guess you plugged into the Mic-In of a laptop computer and between the volume overload and the voice processing, you get what you got.

So why not the USB connection?


You may be able to fix the first half of that by recording in Stereo. After the shoot, use the drop-down menu on the left Split Stereo to Mono. Delete one of them. I still can’t account for the drop in volume.


Thanks Koz…

I’m not for sure I understand your answer.

To me, I use the line connection because I’m going through an audio interface.

So What do you mean, “did I use the USB”?

The Mic is plugged into the interface also, not a computer.

The wave was trimmed because I fit 1h35m into the screen shot.
2017-01-25 (1).png

The wave was trimmed because I fit 1h35m into the screen shot.

No. I don’t mean side to side. I got that. I mean up and down. See how all the waves neatly stop at 0.5 up and down (scale on the left)? That’s broken, or at least not normal. I’m betting that sound is a little grittier and harsher than it’s supposed to be.

See the USB socket on the back of the 2i2? Is that the only cable you have connected to the computer?


A few days ago I had an issue I shared with the forum needing to Amplify the wave form because I wasn’t meeting the criteria of ACX.

It was suggested I move closer to the Mic.

And yes, USB cable is connected to the computer.

Nothing that has been suggested is a solution.


As Koz suggested, the first part of the waveform does not go above 0.5 on the vertical scale. It would be better to fix that by recording in stereo (as Koz said): http://manual.audacityteam.org/man/faq_recording_troubleshooting.html#half_volume. This will allow you to record louder with natural peaks instead of flattened ones.

Let us know if you still get the dramatic reduction in volume after 90 minutes.