We actually reduce the quality slightly in an attempt to get a consistent cross platform sound quality to XMA. The quality setting in the editor is reduced by 15 and then divided by 100 to get an OGG quality setting clamped between -0.1 and 1. If you’re using a quality of 100 that results in an OGG setting of 0.85, which would fall in the range of 256 - 320 kb/s though as that wiki suggests, the quality is not intended to correlate to an exact bit rate.