My mother-in-law lives with us and uses an R-15 on a Sharp SD TV. I see (and hear) her TV often, and there is no volume problem that I can determine. She watches a wide variety of channels. My other R-15 is on Sprout most of the time, when it is on, and the sound is fine, no real noticeable difference when I do change channels. I'm sure some people, maybe lots of people, are having problems, but not everyone has noticed anything out of the ordinary.