No difference in quality has ever been demonstrated by any of the magazines, movie studios or music labels that have done careful tests between DD and DTS. Probably is. Louder, especially if it's a small difference in volume, is almost always heard as an improvement in sound quality. It's an old salesman trick. Both use lossy compression that discards data; the DTS codec is ineffecient compared to DD, which is why it requires so much more bandwidth.