T60 Slope Ratio: Symbolically—T60SR6 A proposed standard for condensing six octaves (63 Hz – 2 kHz) of reverberant decay data into a singular-quotient, qualitative score for performance, worship and entertainment facilities. Specifically, a defining metric for scoring and grading the proportional relationship (i.e., ratio) between the longest and shortest of the six T60 values, measured or predicted, and applied to fully enclosed venues employing sound reinforcement systems. In practice, Bass Ratio and Slope Ratio goals are conflicting concepts. Bass Ratio goals and calculations were developed to quantify and support the idea that acoustic instruments need a little extra reverberant support from a room, in the low-frequency range. Slope Ratio goals and calculations support the notion that those same low frequencies do not require extra structural support, but rather need to be managed and well contained. Longer low and very low-frequency T60s are not needed or desirable when an extended-range sound reinforcement system is being used. The T60SR6 thesis is offered to advance and define a room’s reverberation goals, and provide a simple numeric scoring scale, and grading vocabulary, from which acoustical design specifications can be initiated and evaluated.