I have a broken screen 1520 with D.P. and my current 1520 with Cyan. I was able to compare the sound back to back with the custom EQ I have set up for them. I keep Dolby Enhancement on, and Audio leveling on. I noticed on the Developer Preview the bass had way more punch to it. I noticed the mids and highs on Cyan sounded super good. Overall, I liked the sound quality better on Developer's Preview and WP8 to Cyan. I think Nokia needs to come up with a fix on Cyan for the low-end sound.