Virtual Surround systems attempt to create acoustic images that appear to originate across the space subtended by the virtual speaker locations and the physical speakers. The performance of Virtual Surround systems can be subjectively judged by direct comparison to discrete multichannel reproduction systems. Such comparisons reveal differences in the perceived Virtual Surround and discrete multichannel sound field. Quantitatively evaluating and ranking the localization performance of these systems is difficult because of the large number of perceptual factors which are affected by Virtual Surround reproduction. Evaluation of the localization performance is facilitated by the use of synthetic test signals that are spectrally constrained to a narrow band of frequencies.