I've actually saw the same exact question asked on the forum but I never really got a clear understanding of the answer. I have some good 808 sounds, but I can never get them to sound like the bass/808 in songs like Trey Songz- Bottums Up. Also songs like whatever you like -t.i., on my level-wiz, bedrock- young money (although I don't know if the last 2 are the same as the other one's. they might just be a regular sub bass). I have the heavy "boom" in my samples, but I don't heavy up and down tonal sound they have. Any tips?