Adobe Audition - unusual noise and tone

I have been using Audition for the past 4 years for Voice Over work.  I was working on a MacBook Pro.  I recently got a new computer and iMac.  My recordings on Audition now have a crackling sound in the background.  Also, there seems to be a lot of bass in the recordings.  I never had these problems with the laptop.  I had hoped getting the desktop would give me better service.  How can I resolve these problems?