The UPM-1P is a remarkably compact, self-powered professional sound reinforcement loudspeaker system. It is ideally suited to applications requiring a relatively small and inconspicuous loudspeaker that can also provide high sound pressure levels, extremely low distortion, and uniform directional control. The UPM-1P loudspeaker provides vocal-range reinforcement as a small PA system, or as a fill or delay loudspeaker in larger indoor or outdoor systems. A full-range system can be created with the addition of an optional subwoofer. The UPM-1P high-frequency section comprises a 1-inch metal dome tweeter on a symmetrical constant-directivity high-frequency horn with 100-degree beamwidth. At lower frequencies, sophisticated phase-correction circuitry assures true point-source performance without the off-axis cancellation effects that plague customary dual-woofer designs. Two 5-inch low-frequency cone drivers are driven in parallel at low frequencies to take advantage of their combined acoustic output. To prevent destructive interference and comb filtering effects in the mid-band frequencies close to the crossover area, one of the drivers rolls off above 320 Hz. Two channels of power amplification are provided (350 watts total), along with an active crossover, driver protection voltage limiters, and frequency- and phase-response alignment circuitry. A laser-trimmed differential input stage affords superior common-mode rejection to allow long signal runs through shielded twisted-pair cable. The standard UPM-1P is switchable between the 115 V AC and 230 V AC ranges. A 100 V AC version is also available. The UPM-1P's integral power supply suppresses high-voltage transients, while two PowerCon AC connectors facilitate AC looping. The rugged cabinet is coated with a textured black finish. Mounting is via three 3/8"-16 or metric M10 threaded recessed nut plates. Optional U-bracket, yoke, and pole-mount hardware is available. The UPM-1P loudspeaker can be supplied with either the standard audio input module incorporating looping XLR connectors, or an alternate that adds attenuation and a polarity switch. The UPM-1P easily integrates with the RMS remote monitoring system network and software (optional). RMS displays signal and power levels, driver status, limiter activity, and amplifier temperature on a remote Windows computer.