Characterizing stage acoustics using objective parameters has seen some recent resurgence-several studies have noted the importance of the directionality of early stage reflections to musicians, which is not adequately represented using existing omnidirectional stage-support parameters. This study examines the subjective impressions of 19 chamber musicians against omnidirectional [reverberation time, early and late support (STEarly, STLate), etc.], and proposed spatially-defined parameters (TH and TS), along with simple ratios of stage dimensions derived from measurements on eight purpose-built stages. TH is a ratio of early energy from "above" to that from the "horizontal," while TS relates energy from above to that from the "sides" of the stage. Robust mixed-effects analyses showed that the musicians' overall acoustic impression ratings are predicted (i) by TH within a linear model; (ii) by TH × STEarly,TH × STLate, and TS × STEarly,TS × STLate; (iii) by STEarly, STLate each within parabolic models; and (iv) by several architectural parameters' linear and parabolic models. These findings reinforce recent studies of spatially-defined parameters to more fully account for the subtleties of onstage sound fields. Some simple design recommendations are presented, although future studies are needed to confirm these findings/recommendations for a wider range of auditorium stages.