Complex sentence: Altec Lansing introduced the'604', which was to become their most famous coaxial Duplex driver, in 1943, incorporating a high-frequency horn sending sound through the middle of a 15-inch woofer for near-point-source performance.
Split into simpler sentences: Altec Lansing introduced the "604", which became their most famous coaxial Duplex driver, in 1943. It incorporated a high-frequency horn that sent sound through the middle of a 15-inch woofer for near-point-source performance.