Сабвуферы — Neumann KH 870 II

Neumann designed the KH 870 II as a powered studio subwoofer with DSP control, meant for stereo, surround and 3D monitoring systems with up to twelve channels. According to the manufacturer, it delivers about twice the output of the KH 810 II and extends low frequency reproduction further. A separate KH 870 II AES67 version is also offered for networked audio installations, and the analogue model described here is fitted with intelligent protection limiters for each woofer.

Key specs that matter

Two long-throw 265 mm (10 inch) woofers, protected by a black metal grille, are built around the ELFF principle, short for Extremely Linear Force Factor. The free field response is 18 Hz to 310 Hz within 3 dB and 16 Hz to 750 Hz within 6 dB. The woofer amplifier is rated at 360 W with the limiter active at 0.1 percent THD+N, and power draw at full output reaches 510 W on both 230 V and 100 V mains. Sine wave output with THD below 0.5 percent at 1 m in half space is 95 dB SPL between 33 and 200 Hz. Maximum SPL is 114.9 dB on the floor, 117.9 dB against a wall and 120.9 dB in a corner, and reaches 123 dB SPL when bass managed. The cabinet measures 737 x 330 x 645 mm, and weighs 44.5 kg.

Engineering and use context

This cabinet uses bass reflex loading through front-mounted ports, tuned so that port noise stays inaudible. The built-in Bass Manager handles formats up to 7.1.4 with a fixed 80 Hz crossover and a fourth-order 24 dB per octave slope. For multichannel work two Sub D25 connectors accept up to 12 analogue input channels and another two Sub D25 connectors provide up to 11 analogue output channels, next to two electronically balanced XLR input sockets and two matching XLR output sockets. Seven BNC digital outputs cover channels 1-3, channels 5-12 and a daisy chain link. The DSP applies FIR phase linearisation to connected analogue monitors, and soft clip, peak and thermal limiters with excursion protection guard the drivers.

Pairing

Through its analogue and digital outputs the KH 870 II can feed up to 11 studio monitors, which suits Neumann KH series loudspeakers in a multichannel room. Integration with the connected monitors is carried out with the MA 1 Automatic Monitor Alignment software, which is sold separately.

Alternatives

The Neumann KH 810 II is the brand's smaller DSP subwoofer with roughly half the output of this model.