Neumann KH 870 II 2x10in DSP-Controlled Powered Subwoofer

About: Neumann KH 870 II 2x10in DSP-Controlled Powered Subwoofer

The KH 870 II is the perfect subwoofer for larger rooms, providing powerful bass extension with Neumann precision. It includes a unique and flexible Bass Manager for stereo, surround and immersive systems up to 7.1.4. Analog and digital outputs provide flexible connectivity to up to 11 studio monitors. 

• Deep and extremely powerful bass down to 16 Hz
• The perfect complement to mid-size and large Neumann KH line studio monitors
• DSP-controlled for superior sonics and unparalleled precision
• Room correction via MA 1 Automatic Monitor Alignment (sold separately)
• Supports automatic alignment also for analog KH-line studio monitors (patented)

Next Generation Subwoofer 

The KH 870 II improves on its predecessor in acoustic performance and adds new features. Thanks to two novel long-throw 10” woofers with Extremely Linear Force Factor (ELFF) technology and intelligent protection limiters, the KH 870 II ensures exceptionally low distortion even at maximum SPLs. 

The KH 870 II extends low frequency reproduction down to 16 Hz and delivers about twice the output of the KH 810 II. This makes the KH 870 II the perfect complement to midfield speakers such as the KH 420. 

The KH 870 II is DSP-controlled for superior sonic performance and seamless integration via MA 1 Automatic Monitor Alignment (sold separately). When combined with analog Neumann studio monitors such as the KH 120 A (discontinued), KH 310, or KH 420, it offers sufficient DSP-power for aligning an entire stereo, surround or even immersive system up to 7.1.4 via MA 1, optimizing not only the frequency response but also the phase. Of course, the KH 870 II is also a perfect complement to Neumann’s DSP-equipped studio monitors. In surround and immersive systems, analog and DSP-equipped Neumann speakers can be combined and room-aligned using MA 1 with Multichannel Extension (sold separately). The KH 870 II is therefore much more than “just” a subwoofer: It is the perfect tool for upgrading existing systems and/or extending them for immersive audio. 

Precision in Every Detail 

As subwoofers are typically placed on the floor, robust grilles protect the drivers from accidental damage. The rigid cabinet features a highly efficient bass reflex system, which is carefully engineered and tuned for the tightest bass reproduction – with inaudible port noise. 

Two analog XLR inputs and outputs are available to connect the subwoofer for stereo operation. For multichannel operation, the KH 870 II offers two Sub D25 connectors for up to 12 analog input channels and another two Sub D25 connectors for up to 11 analog output channels. All inputs and outputs are electronically balanced. Studio monitors can also be connected digitally via AES3 (BNC). For audio networking, this subwoofer is also available as an AES67 variant, the KH 870 II AES67. 

The KH 870 II excels in music, film scoring, broadcast, and post-production studios for tracking, mixing, and mastering. Thanks to a novel power amp design, the KH 870 II combines superior audio performance with excellent energy efficiency. Its Auto Standby function can be deactivated in the MA 1 app. 

Benefits 

• Bass extension of the monitoring system down to 16 Hz 
• Increasing the maximum SPL of the entire system 
• Decreasing harmonic and intermodulation distortion of loudspeakers 
• MA 1 Ready for perfect alignment of the entire system and seamless subwoofer integration. For multichannel setups, we offer MA 1 Multichannel Extension option. 
• MA 1 integration of analog KH Line speakers, enough DSP power for an entire multichannel system up to 7.1.4. 

Features

• Ultra stiff wooden cabinet 
  • Tough painted finish and build-in rubber feet for acoustic isolation 
  • Excellent self-damping properties leading to minimal cabinet resonances 
  • No standing wave resonances inside cabinet 
  • Ultra tight bass reproduction due to very low group delay 
• Two in-house modelled long-throw bass drivers with Extremely Linear Force
  • Factor (ELFF) and robust resonance optimized basket 
  • Damping of break up modes brings low distortion at high sound levels 
  • Extremely linear force factor provides low harmonic distortion even at high excursions 
  • Reduced air noise and improved rocking modes 
  • Grille protects against mechanical damage 
• XLR electronically balanced analog inputs and outputs (stereo) 
  • Standard interfacing to professional equipment 
  • Daisy chain input and output for subwoofer arrays 
• Two electronically balanced SUB-D 25 connectors for up to 12 analog input channels and another two SUB-D 25 connectors for up to 11 analog output channels. The pinout follows the Tascam standard. 
• Digital outputs (multichannel)  
  • 192 kHz, 24-bit conversion 
  • 7x BNC: Channels 1-3, Channels 5-12, Daisy Chain Out 
• Network connector using standard IP protocol and your existing network infrastructure 
  • Loudspeaker system including analog KH-line monitors can be controlled via MA 1 - Automatic Monitor Alignment Software. 
• Control function 
  • Toggle switch for selection of two completely independent modes of operation and calibration: on the device or via the network using the MA 1 - Automatic Monitor Alignment software. 
• Universal switched-mode power supply (100 … 240 V) 
  • One version works in any country and is robust to poor quality mains supply. 
• Ground lift to overcome ground loops 
  • Inputs with very high CMRR to reduce noise induced by long cables in electrically noisy environments 
  • Completely symmetrical internal signal flow to avoid electrical interferences 
• Low heat dissipation amplifiers with large headroom and sophisticated protection circuitry 
  • Improved transient response 
  • Assured reliability and safety 
  • Separate thermo limiter to protect the voice coil and power amplifier 
• Soft clip and excursion limiters 
  • Increases system reliability 
  • Allows extraction of the maximum performance from the system 
• Standby function  
  • Reduces power consumption when product is not in use. 

Specifications

• Acoustics
  • Free field frequency response ±6 dB: 16 ... 750 Hz
  • Free field frequency response ±3 dB: 18 ... 310 Hz
  • Self-generated noise at 10 cm (with input gain set to 100 dB SPL for 0 dBu): <20 dB(A) SPL
  • Minimal self-generated noise at 10 cm Self generated noise/ Input gain setting/output gain setting: <20 dB(A) SPL
  • Sine wave output with a THD < 0.5 % at 1 m in half space: 95 dB SPL (33 - 200 Hz)
  • Bass capability: Max. SPL in half space at 3% THD at 1m (averaged between 50 Hz and 100 Hz): 114.9 dB
  • Max. SPL for subwoofers: on floor; against the wall; in the corner: 114,9 dB; 117,9 dB; 120,9 dB
  • Dolby DARDT. Max SPL bass managed: 123 dB SPL
  • Acoustical Principle: Bassreflex, Ports at the front
• Analog Inputs and Outputs
  • Analog input(s): 2 x XLR: electronically balanced; 1 x SUB-D 25: 8 x electronically balanced; 1 x SUB-D 25: 4 x electronically balanced
  • Analog input impedance: >12k Ohms
  • Max. input level: 24 dBu (CH 1...3, 12); 21 dBu (CH 5...11)
  • Common mode rejection ratio (CMRR), XLR / Sub-D: > 56 dB @ 15 kHz
  • Crosstalk (1 kHz), level matching, XLR / Sub-D: -90 dB; ±0.1 dB
  • Remote volume control: via MA 1 software
  • Volume control range; resolution: 0 … -∞ dB; 0.1 dB
  • Analog dynamic range; THD+N (A-D-A), XLR / SubD: 120 dB(A)(CH1...3,12); 116dB(A) (CH5...11) <0.003% (-90 dB)
  • Signal routing modes: analog
  • Analog output(s): 2 x XLR: electronically balanced; 1 x SUB D 25: 7 x electronically balanced; 1 x SUB D 25: 4 x electronically balanced
• Digital Inputs and Outputs
  • Digital input(s): 1 x BNC: Daisychain in
  • Digital output(s): 7 x BNC: 11 x Monitor out; 1 x daisychain out
  • Digital converter: resolution; design: 24 Bit
  • Digital converter: sampling rate: 32 kHz..200 kHz
  • Digital internal sampling rate: 48 kHz
  • Output sampling rate: 48 kHz
  • Dynamic range A-D: CH 1, 2, 3, 12=124 dBA; CH 5...11=121 dBA
  • Dynamic range A-D-A (Converter): CH 1, 2, 3, 12=121.5 dBA; CH 5...11=116.2 dBA
  • Dynamic range D-A: CH 1, 2, 3, 12=125 dBA; CH 5...11=118 dBA
  • Digital sensitivity: -18 dBFS = 100 dB SPL at 1 m
  • Latency ADA / DA: 2 ms (A-D-A)
  • Delay: User adjustable delay range: 0 ... 115 ms
  • Delay: Resolution: time; distance: 20.8 µs; 0.71 mm (0.28 ")
  • Delay: Max. frames Audio-video synchronisation (lip sync): 2 (40 ms) frames; 2.75 (33 ms) frames
  • Delay: Time-of-flight maximum distance: Out of 115 ms, FW based
• User Interface
  • Status Indication: Illuminated Neumann Logo
  • Ground Lift: Yes
  • Control: Local; Network
  • Mains Switch: Yes
  • Mains Voltage: Universal Power Supply 100 V~ … 240 V~
• Electronics - Controller
  • Controller design: Digital; active
  • DSP resolution: 32 Bit Audio, Processing 64 Bit double precision
  • Crossover frequency: 80 Hz
  • Crossover slope: 24 dB/oct; 4th order
  • Supports automatic room calibration via MA 1: Yes; Subwoofer and connected analog loudspeakers
  • FIR phase linearization: for connected analog loudspeakers in combination with MA 1
  • Protection circuitry: soft clip, peak and thermo limiters; Woofer excursion limiter; thermo limiter for the electronics and amplifiers
  • Remote control: via Ethernet and MA 1
  • Display: On; Normal Operation: Neumann logo “White”
  • Display: Identification: Neumann logo “Rosé”
  • Display: Limit / Clip / Errors / Protection /Boot Mute / Shut Down Mute: Neumann logo “Red”
  • Logo Brightness: via MA 1 software
• Electronics - Amplifiers and Power Supply
  • Output power woofer amplifier (THD+N with limiter activated: 0.1%): 360 W
  • Mains Power Supply: input voltage; frequency: SMPS: 100-240 V; 50/60 Hz
  • Power consumption (230 V / 100 V): Standby: <=300mW
  • Power consumption (100 V): Idle: 41 W
  • Power consumption (230 V / 100 V): Idle: 41 W
  • Power consumption (230 V): Idle: 41 W
  • Power consumption (100 V): Full output: 510 W
  • Power consumption (230 V / 100 V): Full output: 510 W
  • Power consumption (240 V): Full output: 472 W
  • Standby: automatic, 20 mins (default)
  • Amplifier Standby: Disabled; user defined in software
• Mechanics
  • Cabinet material: Wood cabinet, aluminum electronics panel
  • Cabinet surface finish; color (front / back): Painted; metallic anthracite (RAL 7021) / black (RAL 9005)
  • Operating conditions: +10° C to +40° C (+50° F to +104° F); <75% RH, non-condensing
  • Transport/storage conditions: -25° C to +60° C (-13° F to 140° F); <90% RH; non-condensing
  • Woofer: 2 x 265 mm (10") with protecting black metal grille
  • Mounting points: 35 mm flange on top panel
  • Dimensions (HxWxD): 737 x 330 x 645 mm (28.9" x 13" x 25.4")
  • External net volume: 157 liters
  • Weight: 44.5 kg (98 lbs 2 oz)
  • Acoustical Axis horizontal: 165 mm
  • Acoustical Axis vertical (from bottom): 365 mm

What's in the Box

• 1x KH 870 II Subwoofer
• 4x Mains Cables, black (EU/KR, UK, US and CN)
• 1x Safety Guide
• 1x Supplement “Getting Started Quickly”