Phosphor Bronze wound strings were introduced in the early Seventies and have become the most popular acoustic string. Phosphor bronze wire is made from approximately 92% copper, 7% zinc and 1% phosphorous. Phosphor Bronze provides nice highs and lows, and pleasant subtle overtones. Phosphorous is used to help reduce tarnish and corrosion.
I've played for 40+ years, and when I got a new Taylor Auditorium body 12 string, I went thru a process of trying over a dozen brands of strings, to see which yielded the best tone and bass response. The auditorium body is a bit small to get the dominant bass response I'm used to, from bigger body guitars. This set yields the best overall tone, with the strongest bass response, without being muddy. In addition, the 10th string is wound, which gives a much fuller sound than the plain 10th strings found on most other sets. I play amplified, thru a Rivera Sedona, which is designed for the Taylor pickup system, and these strings yield the best amplified tone as well. I only play uncoated strings, and these stay live,(keep their tone)the longest of the uncoated strings. I'll stick with these, for this guitar.