The role of the audio engineer in the design of a professional sound reinforcement system is becoming a more and more difficult and complicated one with the advent pre‐equalized speaker systems that must operate at given sound pressure levels before feedback in less than ideal acoustical environments. Possibly the most feedback critical and important speaker systems in “the house” are the monitors—the speakers by which the performer judges himself. The systems engineer must be able to guarantee the acoustic output level over an ever increasing bandwidth approaching the limit of human hearing. Special emphasis must be placed on the high‐frequency response if the system is to be useable for monitoring acoustic guitars and other instruments with high‐frequency content. All this must be accomplished with regard to speaker “break‐up,” efficiency, cost, and complexity. For these reasons a two‐way system using a vented box enclosure seemed to offer an optimum solution for monitoring requirements.