To my hearing, the internal speakers on the S970 have a smoother, more balanced sound. I think it’s an improved sound overall. Don’t know about the power. Didn’t read the specs. I always thought the S950 had a more boomy, bass-prone sound. Others posted the same observation at times. Someone could play a small dinner party or gathering with just the S970 alone, with folks at close range. However, I think I’d always want some external speakers to boost the sound.