A Virtual Performance System (VPS) is a real-time 3D auralisation system which allows a musician to play in simulated acoustic environments. Such systems have been used to investigate the effect of stage acoustics on the performance technique of musicians. This article describes the process of calibrating a VPS using energy-based quantities and goes on to verify this technique by comparing known acoustic quantities measured in a test space with a virtual version of the same space. This work has demonstrated that calibrating a VPS using metrics based on Support will result in an accurate simulation of a test space according to known acoustic metrics such as T30. A comparison of quantities referring to earlier parts of the response, such as Early Decay Time (EDT), show some errors which are thought to be caused by the non-anechoic nature of the reproduction space.