I went down the rabbit hole with flats and found theses to be my favorite, especially when broken in. I use a balanced tension 130 + 95-40 which avoids the common issue with their sets being unbalanced. They start out bright almost round wound like, but over a month or so they mellow out and leave you with a nice fat sound but more brightness than most flats. They do need to be wiped down with alcohol before install, there is some black residue from polishing that makes them sticky. I have a 5 year old set that just sounds and feel amazing, I hope they never break. The B sting is killer compared to others, not to dark or lacking output. Chromes are the gateway into flats but my favorite overall.
D'addario Ecb81 Xl Chromes Flatwound Bass Strings
Regular Light Gauge Flatwound Strings