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sounds like you want the bass to come in with the kick to reinforce it.
1 put a noise gate on the bass track.
2 send the output of the kick track to a bus for example bus 5 (you can create multiple outputs on a track by ctrl clicking on the output
3 set the key of the gate to the same bus (in our example 5)
4 set a fast attack on the gate, adjust the threshhold so the gate is triggered by the kick, now you can adjust the release to control how long the bass plays after the kick comes in.

(try making a TR-808 kick drum sound this way, with a 60hz sine wave for the bass part)