Signal Just cutting out during a line in recording

Hey guys, this is my first post so forgive me if don’t include all info. I’m using 2.0.5 on an HP Pavilion with windows 8. We record our church services live to Audacity from a Mackie sound board to the “line in” port to the HP. Whenever the signal gets really high, the recording just flat lines until it calms down and then it comes back. I have recorded to Garage band to rule out the board as the problem and it worked fine in Garage band. I have reduced the signal to the computer, but it still cuts out at high intensity. Any help is greatly appreciated. I have used Audacity for a long time and I really like it, but this is a huge problem and if I can’t resolve it. I’ll have to switch to another program and I don’t want to. Thanks in advance.

forgive me if don’t include all info.

You’re doin’ fine so far.

I’ll have to switch to another program

Which, unless we can resolve this, might do the same thing. And you thought you were sailing right along there…

I will admit to a blank look as I was reading this. If somebody had a gun and said I had to blind-guess, I’d say you were recording a different thing or service in Audacity than you were in Garageband. It can be sneaky. It’s possible to record from and play to completely different things or pathways in Audacity than other services.

This is good [rubbing hands]. I need to go back and read that again. I didn’t know Garageband was available in Windows.


Maybe some sound-card “enhancement” needs to be switched off.
[ the enhancements are not part of Audacity : they are on the computer’s sound card ]…

possibly an Automatic-Gain-Control [AGC] operating ? ,

The garage band was on a different computer I have.

There are no natural services or pathways that can cause this. Windows Enhanced Services exist for the purpose of processing human voices for Skype or other conference product. In general, human voices work just fine. You can get some very serious damage and distortion during song or music. Cast your mind back. Are all the instances of damage during choir performances?

That still doesn’t 'splain the volume trigger. We’re just parroting other common causes of audio collapse. None of these map perfectly to your symptoms.

I’m going to make something up from floor sweepings. Audacity is recording not from the soundcard directly, but from some other Windows service with a complex signal pathway. If the volume of the show exceeds a certain amount, this pathways starts oscillating ultrasonically (so only your dog can hear it). This falls out of Audacity range (higher pitch than 20KHz) so it seems to drop dead, when actually it’s screaming loudly at some high rate. If you relieve the system of signal from the mixer board, the system eventually calms down enough to break the oscillation and everything drops back to normal.

This could be pure fiction, but I have had actual complex systems behave this way.

So inspect the Device Toolbar and tell us what it says, or post a screen capture.

Do you, or has this computer ever been used to record internet sound or self-record? Either of those can produce convoluted sound pathways.

Screen Shot 2014-10-18 at 6.54.13 PM.png

The garage band was on a different computer I have.

One demerit. You can’t hide information like that. We can only go with what you tell us. So we’re back to the whole computer doing something wrong.

As a fuzzy rule, Audacity has no effects or tools that work during a recording. It’s a feature request, but in general, whatever Audacity captures is the sound presented to it by the computer.

Windows, however, has a whole raft of processing tools that can get you into trouble.


Please don’t make us skip around the posting. Always put new information at the bottom of the thread.

Action Item:
We need to know what Audacity is recording by a reading of the Device Toolbar, or a screen capture.


Is it possible to make an Audacity recording all the way through with your Mac just to have a “Desperation Method” available? Audacity is available on all three computer platforms and with the exception of a Control/Command key swap here and there, it acts the same.

There are several questions floating. Did these problems happen during music? Did you go through the machine and turn off all the “Enhanced Services?”

Can you produce straight tone on your mixer? Boooooooooooooooooo. Smaller mixers tend not to, but I have a stand-alone tone generator I can plug in in place of a microphone.

Set up to record that and slowly increase the volume of the tone from very low. You may need to turn the speakers down or it may make your ears bleed. I use 440Hz, that oboe tone at the beginning of an orchestra. As you increase the volume, that will give you a graphic record of where the system cuts out.

If you have no stable tone available actually sing into the microphone.

“October 19th Tone Test! …oooooooOOOOOOO” and get louder slowly until Audacity cuts out. I really want to see what happens to the blue waves at the exact instance the computer goes into Never-Never Land.

Save a Project and Export a WAV file of the test.