Martin’s SP Acoustic Bass strings are designed for maximum tone and longevity. Ultra-high tensile strength steel cores resist breaking. Acoustic bronze electro-finish provides greater string life.
Martin SP Phosphor Bronze acoustic bass strings have a bronze flashing that provides greater durability without sacrificing tone or playability so you can stay in tune and play longer. Phosphor Bronze has a slightly warmer sound than bronze.
Martin 92/8 Phosphor Bronze is an alloy comprised of 92% copper and 8% tin with traces of lead, iron, zinc and phosphor. These strings produce a bright but slightly warmer sound than the 80/20 bronze. The phosphor in the alloy helps them retain their new sound for greater consistency.