I just set up audacity on my laptop with windows 10. It connected to a a audiobox USB soundcard. I’m looking to record voices with a microphone over instrumentals. The recording is making horrible crackling noises when it ’ s recording over a mp3. Although recording my voice over a live playing source such as a vynil playing on the turntable is fine. Would you have tips to help me sorted the crackiling noises when i record over a mp3?