Simple question I need the right answer

How do I get the right vocal sounds. These are urban hip hop songs. I am trying to get the effect of back up vocals by duplicating the previously recorded vocals. I have tried to pan one left and one right leaving one centered. I changed the pitch on the left and right panned vocals and left the centered track normal. And I tried changing the volume levels on the right and left panned vocals. It sounds great through the headphones, however once placed into a home theater or car cd player it sounds like distortion almost. It just doesn’t have that quality that I’m looking for. Please tell me what I’m doing wrong.

The effect you’re looking for is “chorus”. There’s a discussion of it here:

Bear in mind that the best way to get the chorus effect is to use an actual chorus of people. If that’s not possible, then have your singers sing the same piece repeatedly, then mix them together. You still might need a chorus effect, but the result won’t be quite as fake.

Thank you for the help. That is exactly the effect I am looking for, with the main vocal (center panned) standing out above the background vocals. What I need to know is how to get that effect with the singers own voice for his/her verses instead of using multiple people. I’ve noticed in other songs you can hear the singers voice panned left and right but at different pitches compared to the main vocal. Is there a recommended pitch change to get these effects.