KEF R400b Speaker Subwoofer 2x 250W Class D

imensions | Metric :14-1/4” W x 14-1/4” D x 14-1/10” H | 36.2 x 36.2 x 35.8 cm
Driver Complement :One high-definition 10" long throw woofer, pressure coupled to two 10” low bass radiators
Frequency Response :13 Hz – 200 Hz
Internal Amplifier Power :1500 watts
Auto On / Off :Signal Sensing (US) | Signal Sensing and Switched (International)
Power Requirements :110 volts Alternating Current (US) | 220 volts Alternating Current (International)
High Level Inputs :Two pairs of 5 way binding posts
High Level Outputs :Two pairs of 5 way binding posts
Subwoofer Inputs :One LFE input (for SW preout only)
Low Level Inputs :Two low level inputs: left and right low level in
Low Level Outputs :Two low level outputs: left and right low level out
High Level High Pass Crossover :Non Variable 6 dB/octave @ 80 Hz: Available only with high level inputs and outputs
Low Level High Pass Crossover :12 dB/octave continuously variable from 40 Hz to 150 Hz. Available only with low level inputs and outputs
Low Pass Crossover% :24 dB/octave, continuously variable from 40 Hz – 150 Hz: Available only with high level inputs and outputs or low level inputs and outputs
Available Finishes :Piano-Gloss Black
Accessories :Rubber feet; Isolation spikes
Fuse :8 amp 250 volt Slo Blo (US) | 4 amp 250 volt Slo Blo (International)
Weight | Metric :70 lbs | 31.8 kg
Warranty :5 Years; 3 Years for Amplifiers

Type     Advanced YST II and QD-Bass Subwoofer
Driver     25cm(10'') cone
Dynamic Power     250 W
Frequency Response     20-160 Hz
Advanced YST     Advanced YST II
QD-Bass Technology     Front-firing
High-Efficiency Power Amplifier     Yes
Linear Port     Yes
BASS (Bass Action Selector System)     Yes
Standby Power Consumption     0.3 W
Dimensions (W x H x D)     380 x 368 x 420 mm
Weight     18.5 kg

Crossover Tuning    
Mushrooms    
Description     Active closed-box subwoofer system
Drive unit     ø250mm (10 in) paper/Kevlar® cone long-throw
Frequency range     -6dB at 18Hz and 25/140Hz adjustable (EQ at A)
Frequency response     ±3dB 25Hz – 40/140Hz adjustable (EQ at A)
Bass Extension     -6dB at 18Hz (position A)

-6dB at 23Hz (position B)

-6dB at 28Hz (position C)
Amplifier     Power output: 500W
Rated power consumption:     98W / 1W standby
Input impedance:     33kΩ
Signal / noise:     >90dB
Functions:     Input level (line in)

Input level (speaker in)

Low-pass filter frequency (line in only)

Low-pass filter bypass

Bass extension

Bass roll-off alignment

Auto sense on/standby

Phase switch
Inputs:     Line In (RCA Phono)

Speaker in (Binding post)

12v trigger (3.5mm jack)

Low-pass filter

Active 4th-order, variable cut-off frequency
Dimensions     Height: 325mm (12.8 in) not including feet

Width: 325mm (12.8 in)

Depth: 375mm (14.8 in) including grille and controls
Net weight     15.5kg (34.4 lb)
Finishes     Matte Black

Outer Flange Dimensions | (Metric) :15-1/2” W x 26-3/16” H | 39.4 x 66.5 cm
Cut Out Dimensions | (Metric) :14-3/8” W x 25-1/8” H | 36.5 x 63.8 cm
Depth from Flange | Metric :4” | 10.2 cm
Driver Complement :One 13" Long-Excursion Woofer coupled to a 13" infrasonic Radiator
Frequency Response :14 Hz – 200 Hz
Impedance :4 ohms
Required Amplifier :SubAmp 600 (available separately)
Inputs :One pair of gold plated spring loaded posts
Enclosure :Sealed Medite
Available Finishes :Paintable White
Accessories :Paint mask; Cut-out template; Paintable removable all metal grill
Packaging :One to a carton
Weight | (Metric) :45 lbs | 20.4 kg
Warranty :5 Years