Acoustic Guitar Strings Medium (12, 16, 24, 32, 42, 54) Hi-Beam 80/20 acoustic are designed for extra brightness, to cut through the ensemble playing of bluegrass musicians, as well as derive extra clarity from heavily braced, or dull sounding guitars. Wrapped upon a hex core the new Hi-Beam 80/20 acoustic are handmade and handwound for great tone, and increased longevity.