Bose PowerMatch PM8250N

The Bose PowerMatch PM8250N configurable professional power amplifier provides concert-quality sound with a high level of scalability and configurability for fixed installation sound reinforcement systems. Ethernet-equipped versions enable network configuration, control and monitoring, and an expansion slot supports input from optional digital audio accessory cards. PowerMatch amplifiers utilize numerous Bose technologies to deliver an unprecedented combination of performance, efficiency and ease of installation—all in a reliable, proprietary design.

QuadBridge™ Technology – Allows each 4-channel loudspeaker block to be configured as Mono, V-Bridge, I-Share or Quad modes, allowing the total available power of the amplifier block to be allocated to one or more output channels. The amplifier is capable of driving both low impedance and 70/100V loudspeaker loads directly.

Bose® ControlSpace® Designer™ software – PowerMatch amplifiers can be fully configured using ControlSpace Designer software via the onboard front panel USB connection, or the rear panel Ethernet connection (network models only). Using ControlSpace Designer software you can access additional features including: Parametric EQ stages, load sweep of each output channel and auto standby. ControlSpace Designer software is also used to integrate network model PowerMatch amplifiers into larger control and monitoring systems comprised of Bose ESP processors and CC control centers.

Auto-Standby/Auto-Wake function – When enabled, this function automatically enters/exits Standby Mode, allowing the system to consume less power.

Dual voltage and current feedback loop – Proprietary design combines Class-D efficiency with a unique current and voltage feedback loop circuit that continuously monitors and controls both the current and voltage delivered to the loudspeaker load. Independent of power level and load impedance, the amplifier consistently delivers the widest possible dynamic range, frequency response and lowest possible distortion.

PeakBank™ power supply – Regenerative 4-quadrant power supply enables higher power density while allowing the re-use of energy from reactive loads that is normally wasted in conventional Class-D designs. This highly efficient amplifier design delivers sustainable and repeatable low frequency response.

Fast-tracking power factor correction (PFC) – Efficiently manages the current drawn from the AC mains, allowing the amplifier to drive loudspeakers to maximum output longer without power fluctuation. PFC provides superior transient response and functions at peak burst power much longer than conventional Class-D amplifier designs to satisfy the requirements of even the most demanding program material.

Applications

Houses of worship
Retail stores
Atriums and malls
Restaurants
Auxiliary zones
Conference centers
Hospitality venues

Architects’ and Engineers’ Specifications

The amplifier shall contain all solid-state circuitry, using MOSFET output devices employing Class-D topology and a current and voltage feedback loop circuit. The amplifier shall incorporate a switch-mode power supply with fast-tracking power factor correction (PFC) that will allow full-rated power from AC outlets ranging from 100 – 240 V, 50/60 Hz. The amplifier shall have an IEC 60320-C14 10/15-amp electrical power inlet and shall be equipped with a removable power supply cord. The amplifier shall include protection from shorted and open loads, general overheating, DC, high-frequency overloads, under/over voltage and internal faults.

The amplifier shall contain eight independent amplifier channels, which can be configured to allocate the 2000 watts total rated output power between 2 and 8 channels. The amplifier shall contain variable speed fans, which are automatically controlled to minimize acoustic noise. Fan airflow direction will be from the front panel to the rear panel and should not require air filtering. Rack mounting of multiple amplifiers shall be possible without extra rack spacing for ventilation. The amplifier shall be capable of continuous operation at 1/3 of rated power into 4-ohm loads, in ambient temperatures up to 104° F (40° C). The typical current draw at 1/3-rated power shall be 8.1 amps with 120 VAC and 4.1 amps with 230 VAC.

The power amplifier shall meet or exceed the following performance specifications:

Analog input sensitivity for rated output: 0, +4, +12 and +24 dBu, user selectable
Rated output power, per channel, with all channels driven at less than 0.1% THD, typical (1 kHz): Mono mode with up to 8 channels, 250 watts into 4 and 8 ohms. V-Bridge mode with up to 4 channels, 500 watts into 4 ohms, 8 ohms, or with 100V lines (at 1% THD), 400 watts with 70V lines (at 1% THD). IShare mode with up to 4 channels, 500 watts into 2 ohms. Quad mode with up to 2 channels, 1000 watts into 4 ohms or with 100V lines (at 1% THD), 800 watts with 70V lines (at 1% THD)
Frequency Response (±0.5 dB at 1 watt): 20 Hz to 20 kHz
Signal-to-Noise Ratio (below rated power, A-weighted with +24 dBu analog input sensitivity) >99 dB
Total Harmonic Distortion (1 watt from 20 Hz to 20 kHz): less than 0.4%
Intermodulation Distortion (SMPTE 60 Hz and 7 kHz): less than 0.4%
Channel Separation (adjacent channels at 1 kHz): greater than 65 dB
Damping Factor (10 – 1000 Hz, 4 ohms): greater than 1000

The amplifier shall incorporate eight balanced analog inputs, with rear-panel mounting and utilizing 3-pin terminal block connectors. The analog inputs shall support up to +24 dBu input signals. The amplifier shall support a digital expansion slot capable of receiving 8 digital audio channels using optional digital expansion cards, available in proprietary and industry-standard protocols. The amplifier outputs shall terminate with 8-pin, high-current, terminalblock connectors, which accept 10-22 AWG cables.

The amplifier shall include digital signal processing (DSP) optimized for loudspeaker processing, with 24-bit, 48 kHz operation. The total latency (analog input to amplifier output) shall be less than 0.95 milliseconds. The fixed-block signal processing shall include the following elements for each of the eight channels: 5-band parametric input EQ, array EQ, bandpass (crossover) filters, 9-band parametric output EQ, delay, output peak and RMS-average limiter. An 8×8 matrix mixer shall be included for routing and attenuation of any input/output combination. A signal generator supporting tone, noise and sweep functions shall be included, which shall also enable the amplifier to measure, record and store automated impedance sweeps on any output channel.

The amplifier front panel shall contain a user interface with a 240 x 64 LCD primary display, with LED indicators for signal present, input clipping, output limiting and fault. Functions accessible from the front-panel interface shall include output configuration, fault logging, mute, input sensitivity selection, output attenuation, EQ on/off per channel and loudspeaker processing preset recall.

The amplifier shall contain a PC interface with a front-panel USB connection, which will allow full amplifier setup, configuration and monitoring using Bose® ControlSpace® Designer™ software (PM8250N model only). The network version amplifier shall also contain a rear-panel Ethernet interface available from an RJ-45 connector to allow serial over Ethernet communications and network control/monitoring of multiple network version amplifiers when using a PC running Bose ControlSpace Designer software.

The amplifier chassis shall be constructed of steel with a durable black finish. The dimensions of the amplifier shall allow for 19- inch (483 mm) EIA standard rack mounting. The amplifier shall be 3.5 inches (2RU, 88 mm) in height, and 20.7 inches (525 mm) in depth.

The amplifier shall weigh 28.3 pounds (12.8 kg). The amplifier shall be the Bose PowerMatch® PM8250 (PM8250N) configurable professional power amplifier.