DEAN MARKLEY ACOUSTIC GUITAR STRINGS PhosBronze™ Acoustic: Different guitars respond differently to different alloys. Some sound better with Bronze, some sound better with PhosBronze™. If you want a lot of power and punch, with lots of midrange and highs, or your guitar’s top needs extra punch to project, try a couple of different gauges to find just the right gauge for your guitar. PhosBronze™ is powerful and very bright while still having a smooth low end. PhosBronze™ comes factory equipped on many acoustics.