Vocals recorded over "karaoke" track are off

I import an instrumental of some sort, I then proceed to try to record my voice over it however it is always off beat and I know for a fact I, myself am on beat. Im recording myself at 48000. I have tried several things and looked at old forums etc but can not seem to fix the problem. Any help?

That’s overdubbing. Adding new music or voice overlaying existing tracks.

There’s a process in Overdubbing setup where you cancel timing problems—recording latency. After you make that adjustment (and assuming your machine doesn’t move around), each new track should line up with the old ones.

http://manual.audacityteam.org/man/tutorial_recording_multi_track_overdubs.html

There is one sticky problem with this. If you listen to the computer while you’re performing, chances are really good you can’t be allowed to hear yourself during the performance. That’s machine latency and it’s generally not adjustable.

We published three different methods of using specialist hardware that allow you to hear everything during the performance, but you have to listen outside the computer.

Koz