The Hertz Mille Pro speakers have one single emission point with linear-phase characteristics for clear timbre, allowing for a more detailed soundstage. To improve the tweeter’s resonance, the “Center Tuning Duct” geometry was implemented. This reduces the frequency of the tweeter resonance, and the damping materials on the inside make for a linear acoustic emission. To use an acoustic lens to maximize the off-axis response, and because the 36 mm woofer produces deep and controlled bass frequencies, the acoustic lens is used with door installation of coax speakers.