Presonus

The Eris E44 and E66 offer an extended frequency response e highly accurate and the widest stereo sound field available in their range. Their configuration Nested midwoofer-tweeter-nested Midwoofer (MTM, also known as "D'Appolito") offers an off-axis response and resolution improved spatial. Conventional 2-way designs can cause significant initial reflections from their environment surrounding. The E66 exceed this by positioning a driver ad 1.25 "high frequency, with silk dome, between two drivers from 4.5 "(E44) midrange. The two small woofers work in parallel to partially contain the dispersion of the tweeter, minimizing phase shift. The result is an incredibly detailed stereo image. Both the E44 that the E66 have two midrange drivers that cover the same frequency range. The drivers are placed so that their acoustic centers are less than one length wave for each of the frequencies they reproduce; of consequently, the combined signal of both drivers is propagates forward as a single waveform.