I have Cubase 8 LE. How come every new track that I record has the sound of the previous track I recorded in it? For instance. I set up a drum beat metronome track. Then when I record the new track that beat is in that track. Is there a way to stop it from recording the previous tracks into the new track. By the end of a recording with multiple tracks it can get pretty messy.
Turn off loopback on your audio device.
I am using an alesis 4 track audio interface. I do not see anything in it that resembles what you are talking about. I went through the Cubase software and don’t see anything caked a sound device. I also don’t see anything called loop back in my laptop pc.
If you could be little more specific, or dumb it dumb it down for me I would appreciate it.
It’s always best to list your exact software, hardware, and computer O/S for the best assist. Also please describe exactly what type of tracks you are recording on and what the track inputs and outputs are set up as. This info would be found in the inspector.
Regards 
I can only be so specific, as the info you provide is.
With that kind of mixer / audio interface, you are routing back the playback of the computer to the recording channel. Should be explained in its manual how to set it up to avoid this. There is probably a button for the USB routing somewhere.