I've been recording with Audacity for about a year now and just recently, when I switched from being a Windows user to a Mac user, I found that Audacity is recording too quietly. Well actually, when I record things by itself, it records perfectly fine. But when I'm singing with another off-vocal track or something, my recordings are extremely quiet and almost completely inaudible. However, Audacity says other wise. It shows that the audio is loud/a moderate volume and even when I scream at the microphone, and when the audio peaks, it still ends up extremely quiet underneath the music. And I'm pretty sure it isn't the music's fault. I tested the same thing with an off-vocal track which has very quiet instruments playing, quite slowly and still-- the recorded audio is really quiet.
I'm pretty sure it isn't my sound card(or whatever is used in Macs) since playing music in iTunes sounds perfectly fine and the same as when I first got the computer.
Here's an example:

The recorded track, which shows to be at a moderate volume plays really quietly even when the other track's volume is lowered.
I never had this problem with my Windows version of Audacity-- even if that computer had HORRIBLE speakers.
Any and all help would be very much appreciated!
Thank you.
Boy, I hope this is in the right board!