I currently have a Denon avr788. I think it's the same as the 1708 just a different model number based on what store was selling it.

Looking to get either a set of M80's or M60's. Wondering if that receiver is enough or will I need to upgrade?

my room is 22 x 26 and I was at merchman's home listening to his M80's and at about 8' away it was at 85db and was about 78ish at 16' back. His room is smaller so the measurement was from the adjoining open room to get an idea of what level I'll be listening to them at. Needs to be about that level due to the noise of my eliptical machine and the fan on it. Plus who exercises to music at low levels.