Well the sound signature is more similar to the D2000 than the HD600. If that's what you're looking for. The HD600 is more neutral but also slightly less technical then the HD650 while the HD650 is more musical with a strong focus on it's amazing midrange, good bass, and the most unfatiguing treble I've ever heard. There is literally no sibilance on the HD650 and the treble has very good sparkle. The HD650 has great range as well reaching extremely high and low.