Replace panel or add subpanel?

Gentlefolks,I am in discussions with a builder for finishing the basement, including a dedicated listening room. For the most part, he seems to get audiophile requirements (e.g, running a dedicated line). He proposes installing a subpanel and running everything for the room off that. But if there are problems with the old panel, won’t I create a problem of garbage-in-garbage-out? Wouldn’t I be better off replacing the old panel with a new panel? Much thanks, 
pingvin