Nice rack. You're descending way too fast. You're also going too deep. You can't go that low and maintain the necessary tightness in your hamstrings to generate a good bounce. Push your knees out, set your low back and control your descent. If you do this all correctly, you should feel the "bottom" right after your hip passes the plane of your knee joint and you should bounce off your hamstrings. Quit doing that silly shit with your hips before you start, too.