Unwanted distortion on recorded audio

Audacity Help Forum Windows
1

Windows 10
Aud 2.1.2
I am pretty sure I used the .exe

I am a newbie, but have done the things I know to try within reason so some help would be much appreciated.

Like the title says, I have unwanted distortion on the audio I record. When I say distortion, it is not a constant drone or fuzz at all times. It does seem to the sound wave itself that is distorted. I can even see after recording that it will sound distorted just on the wave shapes. But it is occurs at all parts (loud or quite). My audio input levels are around -30 to -40db. This issue started off intermittently, but is now constant and has become quite irritating. I am going through a focusrite saffire pro preamp. This occurs whether I am going through a mic (shureSM57) or even if I run my electric guitar through.

I do not think this is due to clipping, as I have been watching that carefully on the preamp as well as on audacity.

To check my gear, I have tried changing audio cables, trying different inputs on the preamp, direct in from electric guitar, recording acoustic guitar with mic, its always the same overbearing obnoxious distortion.

However, when I play back the sound directly from the preamp, the sound is NOT distorted. This leads to me to think there is not likely an issue with the preamp itself. So it seems this issue must be with how the signal is getting from the preamp and into audacity. I have tried to change up the sample rates (44.1 vs 96) and it was the same. I have also tried changing the sample rate converted from best quality to medium quality (not sure if I actually need that).

Sorry if this question has been addressed, but my searches thus far primarily return threads on distortion issues due to high input volumes, which I don’t believe to be my issues.

Any suggestions?

2

My audio input levels are around -30 to -40db.

That’s too low and that might be the problem. The analog-to-digital converter in your interface shouldn’t clip until you hit 0dB.*

If you’re not digitally clipping or getting glitches/gaps, distortion is almost always an analog problem. (But, you’re saying the analog sounds OK…)

Just a guess - At low levels you are not getting the full 16-bit or 24-bit resolution and you can get quantization noise. Quantization noise “rides on” the signal so you don’t hear it with dead-silence like regular analog noise. You won’t normally hear quantization noise with 16 or 24-bits, but if the levels are low and you boost the recording 30 or 40dB you are also boosting the quantization noise and it might become audible. (If you want to know what quantization noise sounds like, try saving a good recording at 8-bits.)




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  • Just as an experiment, you might want to check to see it you can hit 0dB with your setup… If you record in mono from one channel using a stereo interface, sometimes it will clip at -6dB because it’s expecting you to mix both channels to mono and it’s trying to leave room for the other unused channel.

You’ll want to leave some headroom for unexpected peaks, but it would be useful to know what your limits are.