As consumer technology advances at ever faster rates, professional technology increasingly finds itself trying to keep up. An example of this is the advent of the Blu-ray and other high definition formats that have increased the audio channel count to 7.1. 

The KH 870 is an answer to these new demands by offering a new 7.1 High Definition Bass Manager™ This is compatible with all standard consumer formats from mono through to the latest 7.1 HD systems. Eight channels of analog or an optional 8-channel, 24-bit, 192 kHz digital input card ensures flexible interconnectivity for modern studios. Four-mode LFE-channel processing guarantees compatibility across all formats and industries. Forth-order crossovers and flexible acoustical controls allow for seamless system integration. Built-in volume control and a hardware remote control allows for centralized system control independent of the source, and the electronics can be remote located to reduce cabling

The latest amplifier technology and acoustical components have been used to ensure the most accurate sound reproduction possible. Robust drivers, a rock-solid cabinet, and carefully designed ports guarantee a tight, articulate, and distortion-free low frequency reproduction, even at high replay levels. Using the sum output, Plane Wave Bass Array™ (PWBA™) techniques acoustically improves lateral consistency in the listening area. The bass extends down to 18 Hz.

The KH 870 subwoofer is designed to complement our extensive range of monitors, and can be used on its own, or daisy-chained to make larger systems capable of higher SPL. The KH 870 can be used in music, broadcast, and post production studios for tracking, mixing, and mastering. The cabinet can be positioned next to a wall or flush mounted into a wall due to the front mounted port, and can be mixed freely in multichannel systems with other loudspeakers from our range – Product Selection Guide

Block Diagram (Download)

Flexible electronics

	7.1 Channel High Definition Bass Management™ compatible with all formats from mono to 7.1
	Bypassable 4th order 80 Hz active crossover for maximum compatibility with consumer reproduction
	0 and +10 dB LFE gain and 4-mode LFE processing:   LFE to subwoofer and left/right   LFE to subwoofer only up to 80 Hz   LFE to subwoofer only up to 120 Hz   LFE to subwoofer with no filtering – for daisy chaining subwoofers and external signal processing systems
	Independent control of bass management for front and back channels
	System wide volume control via optional hardware remote controls or RS-232
	Acoustical controls adapt the subwoofer’s response to the environment   Output level   Low cut   Parametric equalizer   45° step phase control with a built-in test signal
	Larger systems and Plane Wave Bass Arrays™ maybe constructed using the Sum output
	Remoteable electronics (REK 3 and an SC nn) for installation convenience, less cabling, and convenience of use
	Integrated electronic limiter for amplifier and driver protection
	Low heat dissipation amplifiers
	Electronics can be remotely powered on with two modes of operation (0 V and 12 V trigger)

Robust drivers and cabinet

	Low frequency extension for main loudspeakers down to 18 Hz
	Low distortion magnetically shielded long-throw drivers
	Reduced bass compression at high SPL from generously proportioned bass reflex ports
	Large system with 6 dB higher output than KH 810
	A main loudspeaker can be mounted onto an KH 870 to make a large 4-way column system
	Allows main loudspeakers to play louder and with lower distortion
	Wooden cabinet with a tough painted finish (anthracite or silver) and high density rubber isolating feet
	Excellent self-damping properties leading to minimal cabinet resonances
	Cabinet look conforms to the family design

Extensive accessories range

	Remote controls (NRC 1, SEA 1) and remote cables (RC 2, RC 5, RC 10, RC 15, RC 20, RC 25, RC 30)
	Remote electronics Kit (REK 3) and driver cables (SC 2, SC 5, SC 10, SC 15, SC 20, SC 25, SC 30)
	Flight case (FO 870)

Acoustics
-3 dB free field frequency response	18 - 300 Hz, ± 3 dB
Pass band free field frequency response	19 - 300 Hz, ± 2 dB
Self-generated noise level at 10 cm	< 20 dB(A)
Sine wave output with a THD < 0.5 % at 1 m	40 Hz @ 95 dB SPL
Max. SPL In half space at 3% THD	116.7 dB SPL
Max. SPL with pink noise in half space at 1 m	112 dB SPL
Averaged between	40 and 90 Hz
Electronics
Amplifier, cont. (peak) output power (THD < 0,1 %)	320 W (400 W)
Controller design	Analog, active
Main channel crossover frequency	80 Hz
Crossover slope	24 dB/oct
Equalization - Low cut	30 Hz, 0 … -12 dB
Parametric Equalizer	Bypassable
Parametric Equalizer - Gain	+4 … -12 dB
Parametric Equalizer - Frequency	20 … 120 Hz
Parametric Equalizer - Q	1 … 8
Time of Flight adjustment delay	0 … 4.69 ms @ 80 Hz (4-step 0, 45, 90, 135), - 180° Switch
Volume Control	Hardware remote or RS-232
Calibration Tools	Internal signal generator
Protection circuitry	Peak and Thermo Limiters
Infrasonic filter frequency; slope	6.5 Hz; 12 dB/oct.
Remote control	On a CAT-5
Analog Inputs and Outputs
Input/Output channels	7.1 / 7+Sum
Impedanz electrically balanced	XLR, 13 kΩ
Input sensitivity	-8 and +6 dBu
Max. input level	+19 dBu (6.9 Vrms) / per channel
CMRR	> 60 dB @ 15 kHz
Interchannel isolation (1 kHz), level matching	-95 dB, ±0.1  dB
Volume control range, resolution	118 dB, 0.25 dB
Dynamic range, THD+N	119 dB(A), <0. 001% (-100 dB)
LFE Modes	80+re-routing, 80, 120, wide
LFE Gain	0 / +10 dB
Gain Control	+2 … -12 dB
Displays and Mains Power
Displays and indicators: power on	Red LED
- limit/clip	Red LED “Flashing”
- bass management active	Green LED
Mains power	220 - 240 / 100 - 120 V AC (switchable)
Power consumption - Idle	30 W
Power consumption - Full output	550 W
Mechanics
Cabinet surface finish	Painted
Color: standard	Anthracite (RAL 7021)
Baffle cover	Included metal grille
Drivers	Magnetically shielded
Woofer	2 x 265 mm (10")
Height x width x depth	735 x 330 x 645 mm (28.9" x 13" x 25.4")
Internal net volume	86 l
External volume	156 l
Weight	47,1 kg (103.6 lbs)
Accessories	FO 870, LH 37, , REK 3, NRC 1, RC 2, RC 5, RC 10, RC 15, RC 20, RC 25, RC 30, SC 2, SC 5, SC 10, SC 15, SC 20, SC 25, SC 30

Product	Article No.	Description
KH 870	503947	2x10” Active Studio Subwoofer with 7.1 High Definition Bass Manager™, 100 - 240 V, anthracite (RAL 7021)
KH 870 G CCC	505566	2x10” Active Studio Subwoofer with 7.1 High Definition Bass Manager™, 100 - 240 V, anthracite (RAL 7021), CCC Certified

Note: CCC versions for the Chinese market will not be shipping until early 2012.