The HD-1 high definition audio monitor is a self-powered loudspeaker designed for ultra-precise near-field monitoring. Optimized to approximate a point-source radiator, the HD-1 yields exceptionally broad directivity with a generous "sweet spot." Its patented circuitry minimizes time delays and deviations from linear phase.The HD-1 incorporates a two-channel power amplifier and a sophisticated active crossover with optimized pole-zero filters for acoustical transparency and a flat frequency response.The power amplifier features complementary MOSFET output stages and operates at class A at low to moderate levels (less than 90 dB SPL) and class AB at high levels.The HD-1 delivers a high peak SPL with a dynamic range of over 100 dB, with extremely low distortion.Its free field frequency response is flat (within +/-1 dB) from 40 Hz to 20 kHz, with each unit being individually calibrated at Meyer Sound's Berkeley, California factory.The HD-1 has an active, balanced input that is switchable between a +4 dBu and -10 dBV nominal operating level.The HD-1's transducers include a low-frequency 8-inch cone driver and a high-frequency 1-inch soft dome tweeter.The low-frequency driver's ample magnet and 2-inch voice coil yield high efficiency with rapid heat dissipation.The tweeter employs a silk-infused dome that affords smooth frequency responses while minimizing breakup and coloration.Both proprietary drivers are housed in a vented cabinet and individually tested for maximum linearity and low distortion.