The Eris E44 and E66 deliver an expanded and highly accurate frequency response and the widest stereo field available in their class. Their nested Midwoofer-Tweeter-Midwoofer (MTM, also known as D'Appolito) configuration offers improved off-axis response and spatial resolution. The result is a more consistent listening experience, smoother frequency response, and an ultra-wide, detailed stereo soundstage. Conventional 2-way designs can cause significant early reflections from their surrounding environment. The E44 and E66 overcome this by positioning a 1.25-inch, silk dome high-frequency driver between two 4.5-inch (E44) or 6.5-inch (E66) midrange drivers. The two smaller woofers work in parallel to partially contain the dispersion of the tweeter, minimizing phase displacement. The result is incredibly detailed stereo imaging. Both the E44 and the E66 feature two midrange drivers that cover the same frequency range. The drivers are placed so that their acoustic centers are less than one wavelength apart for any of the frequencies they reproduce; as a result, the combined signal of both drivers propagates forward like a single waveform. This makes the comparatively small midrange drivers in the E44 and E66 behave like a single, larger driver. This mutual coupling provides a highly dynamic output in a compact footprint.