Panning is one of the most important parts of making a rap beat with a high quality "stereo image". A stereo image is basically two things: left to right and front to back. The panning knobs take control of the left and right axis of your music. Everything else: volume, reverb, filtering, and ambiance have to deal with the front and back.
Imagine yourself sitting in the front row, watching the live performance of your beat. Where is your drummer? Where is your keyboard player? How about your violins? All these things are very important when creating your "stereo image".
The most important tip for a great good stereo image is to give each instrument its own unique space. You want to keep each instrument away from each other so that they don't compete or overlap. What happens when you put two or three guitar players on top of each other? Think about your live performance, separate the guitar players to opposite sides of the stage.
A good starting point is looking at a classic rock band example and then you can go from there. The kick and snare are centered dead middle, with the cymbals a little to either side. Conga players tend to go on the left end. Woodwinds, which are very melodic most always go in the center. As you go over to the right, the sound goes from soft to hard, from sweetness to the hard sounding trumpets and tubas. As you go left it gets much more delicate, with soft horns, piano and the harp. In the back you have the short and louds, things like drums and Timpani. The front is reserved for the long and soft sounds, the strings.
One key point to remember is that less is always more. Most of the time you never have to pan anything all the way. Its rare that you would completely max out any one fader or effect. Just by using little bits of signal here and there to separate your audio is going to give you a much better stereo image.
Now that you have a few really good tips on panning, you need to know that panning and creating beats are not exactly the same thing. There are tons of other factors that go into the process of making and finishing a beat. Remember the tips and info here and then go on to learn more about layering, using equalizers, and also adding reverb. There is always so much more to learn and more time to practice your skills as a musician. Music is something that can catch on quick but then take a lifetime to improve. With that being said, good luck making and panning your rap beats!
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