Hi there
I’m new here and not very techy so apols for my terminology. I’ve got a new second hand Apple desktop (Retina 5k, 27 inch, 2017) and I’m having problems recording (I’m a voiceover artist) as the wave line is permanently wobbly. There is no sound attached to this wobble. I’ve turned the dither off and checked with 3 very techy friends who can’t work out what the problem is. Any ideas? I’ve got a laptop and another apple desk top that are fine and downloaded audacity from them.
Jo
Select the track then do Effect > Amplify. (Depending on how you’ve organized your Effect menu you may have to go through a sub-menu to get to the Amplify effect.) Then listen to the track.
When posting pictures of the screen in the future, note that you can press Command+Shift+4 to take a screen shot of a portion of the screen.
Hi again
Apologies I’ve been away so unable to take a picture of my screen, also I struggled to take a picture using the command shift 4 method. I keep ending up with a blank picture. But I did amplify the sound and you still can’t hear anything. And I took a photo of it with my phone. I’m totally stumped as to what it could be.
Thanks again for taking the time to give me your advice. You sound like you know what you’re talking about and I really hope you have the solution.
Take care
Jo
Then, you obviously only selected a white area of your screen…
1 place your mouse on one edge of the area you want to show
2 hold down the left mouse button
3 drag diagonally until you reach the opposite side of the area
4 release the mouse button
Your screenshot should appear on your desktop (if you did not change where it should be saved).
Your recording problem: Did you see the input volume slider? it is probably near to the left edge in your setup…
Hi again
How do I get the input volume slider to move. It’s currently on 0. And I’m still struggling to get a screenshot and just getting a blank page. 
Very sorry…
because it’s ~20Hz, (human hearing cannot perceive it) …
If you apply a high-pass filter at say 80Hz it will be removed from your vocal recording without harming it. (even if you don’t filter it out it’s a negligible artifact).
Hi Trebor
Thanks for your reply. What’s a high pass filter, is that a settings thing I can do before I record permanently so it’s never a thing I’m having to deal with? And do you know what’s causing it? I don’t have it on my other desktop which I use with audacity so am really intrigued as to what’s causing it…
Thanks again
Jo
It passes high frequencies (above the cutoff frequency) while cutting lower frequencies (in this case it’s cutting “bass” below the vocal range).
The traditional audio range is from 20Hz (very-deep bass) to 20kHz (very high frequencies that usually only young people can hear).
On the low-frequency end, most music and most pro subwoofers go down to around 40Hz. That’s low enough for bass you can feel in your body if it’s strong enough.
You can use Audacity’s Generate function to generate sine wave tones at different frequencies if you want to get a feel for the frequency range.
Audacity can’t apply effects during recording.
It has to be done after recording. High-pass filtering is part of the standard-recommended audiobook mastering process because with a voice recording any low frequencies are just junk (noise).
Many pro studio mics have a low-cut switch for the same reason.
It depends on what’s different. It could be your soundcard/interface. The preamps built-into regular soundcards tend to be noisy. Or it could be that your microphone is picking-up vibrations from the floor, etc., and one of the soundcards is “better” at passing-through the low frequencies. Shock mounts are also common on pro microphones. Or, maybe it’s fan noise/vibration.
A/D converter can generate infrasonic artefacts. Normally they are filtered out.
If you post a few seconds of the audio we can check what it is , e.g.
[inaudible infrasound]