Input volume / waveform screen shots / breakup + cracking

I’m using Audacity 2.2.2 on an iMac running 10.13.4 connected to a Roland RD-2000 stage piano keyboard via a USB cable. I have the following queries and would be grateful for any advice:

1. I want to increase the input volume of the Roland keyboard, but the Audacity slider is greyed out and it states ‘unavailable use system mixer’. In the iMac system preferences > sounds when I select the Roland RD-2000 for input it states ‘the selected device has no input controls’. How can I control the input levels?

2. Maybe linked with item 1 above, I’m noting that the R right channel is playing back at a higher level (approx. 6db) compared to the left channel. I’m assuming this is originating from the recording level as my speaker output is set equally between L and R. I have no control over the output mixing as noted in 1 above. Can I override this?

3. How do I get a screen shot of a recorded waveform – all the internet guides I can find show how to do this in Windows but not on a Mac, and the interface and menu items are different.

4. I’m getting occasional breakup on a recording – not evident when the keyboard is played – ie it only appeared in the recording. Any thoughts on the reason for this? Connecting cable, interference?

5. I’m also getting some cracking sounds when playing back through the RD-2000 speakers (which I don’t experience when actually playing the RD-2000 at the same volume), and the cracking happens in different parts of the recording if the recording is played back a number of times – ie cracking not in the same consistent places, and the cracking isn’t evident when the recording is played back through my computer. Any suggestions as to the cause?

Thanks in advance

How do I get a screen shot of a recorded waveform

Shift-Command-3 will take a picture of the whole screen and put it on your desktop. Shift-Command-4 will give you a cursor so you can draw a box around the point of interest.

Koz

Audacity tends to believe the Mac when it says the device has no volume controls.

So you have to do it at the Roland. When the music cracks and pops, what does the timeline look like? Overload distortion looks like blue sound waves that go too far up and down. You can View > Show Clipping and the timeline will give you thin red bars in all the places that are in danger of sound damage.

I did that with Shift-Command-4.

Koz