When I first got my 950, I set my speaker levels by ear and was conmvinced that not only did it sound good, but my golden ears had helped me set the levels quite accurately. When I picked up an SPL meter a few weeks later and re-calibrated, I discovered not only that my ears were not as golden as I thought, but that everything sounded so much smoother and natural. Considering what we pay for all the other components in our systems, the RS SPL meter is a tremendous value.