I finally figured out what double flange tips I've been using on the N20- RHA large double flange. These are great on the N20. They allow me to get just the slightest bit looser seal than stock tips, due to their really short stem. The slightly looser seal allows me to drop bass quantity just a little to get a slightly more neutral overall response. At any rate, still loving the upper mid and treble presentation. Really engaging for rock music.