Building better loudspeakers is only the first of many performance challenges that face all audio design engineers. Controlling the sound as it leaves the speaker enclosure is as critical to the performance of the system as the quality of the source component. The goal is always the same: create a consistent sound pattern throughout the desired vertical and horizontal plane without introducing artifacts, while ensuring the full bandwidth and SPL capability of the transducers, and providing a seamless transition from high frequency to low frequency components. JBL engineers relentlessly test new shapes and develop new materials to achieve the desired performance, often inventing new testing methodologies to ensure that nothing is left out of a thorough and rigorous examination of the design. The resulting technology has produced such groundbreaking designs as the Progressive Transition Waveguide, Image Control Waveguide, Slip Stream Port, Radiation Boundary Integrator, and Constant Curvature Waveguide. With multiple patents, and many successful installations in use worldwide, this critical component of JBL technology continues to evolve through our continuous pursuit of better, more accurate sound.