I used to play my '76 a lot. And I always had this problem: While playing the first six positions on the E-string on my own, I heared them loud enough. When I played the same positions with the band playing, I often didn't hear them. (I did feel them, though). The first times I thought my bass or amp broke down, I looked to my bandmates and public, but nobody seemed to notice any lack of bass. Cos it was there... It was just me, not hearing those tones.
Is that about the curve I'm going to google?