Special Features
Controls
Indicators
Inputs/outputs
More specs and notes

Special Features

Protection circuitry protects the amplifier when:

• The speaker wires are short circuited to each other or ground
• The internal operating temperature exceeds 248 degrees F
• DC output to speakers is detected
• The amplifier is receiving low voltage
• The Sigma Servo connection is made incorrectly

B.M.S. (Bass management System) This amplifier features B.M.S. which allows you to control various bass functions either manually (when used with a normal head unit), or remotely when used with compatible Kenwood eXcelon head units equipped with B.M.S. controls.  This feature turns the cooling fan of the unit on and off, opens and closes a sliding panel on the top of the unit, and applies 0, 6dB or 12dB of bass boost as explained in the controls section.

Sigma Servo: The Sigma Servo system uses feedback from the speaker to better control the speaker's motion. A negative feedback loop extends to the speaker's positive and negative terminals to reduce speaker movement after a signal stops. By tightly controlling the speaker, Sigma Servo helps prevent muddy sounding bass. Sigma Servo raises the amplifier's damping factor to more than 9900, resulting in excellent transient response and lower distortion. Note: The Sigma Servo feed back connections MUST be made, or the sound level may fluctuate and noise may be introduced.

Band Reject Filter: The band reject filter switch can be used along with the band reject frequency control to filter out a small band of frequencies that are emphasized and causing the system's low frequency response to sound uneven and excessively boomy or muddy. The filter band is continuously variable from 40 to 200 Hz.

Controls

The variable input sensitivity knob adjusts input levels from .2 to 5Volts. (under the top panel)

A LPF Filter switch is used to turn the 24 dB/octave low-pass crossover "off" or "on".

A low pass frequency control is used to set the low pass frequency and is variable from 50-200, 18dB/octave slope (under the top panel).

The Infrasonic frequency switch can be set to "off" or "on". 

Infrasonic Frequency Switch: When the Infrasonic switch is set to the "on" position, this switch is used to select the cutoff frequency (15, 20, 25 or 30Hz) of the infrasonic filter. This allows you to filter frequencies that may robbing power from frequencies that the system can reproduce without distortion. Use of the infrasonic filter allows better amplifier efficiency and better audible sound (extremely low frequencies can be stressful to an amplifier and loudspeakers and can muddy audible frequencies).

Band Reject Filter (BRF) switch: This switch may be set to "off" or "on". The band reject filter switch can be used along with the band reject frequency control to filter out a small band of frequencies that are emphasized and causing the system's low frequency response to sound uneven and excessively boomy or muddy.

BRF frequency control: A variable control that allows you to adjust the center frequency at which Band Reject Filter (when the BRF switch is set to "on") operates.  May be varied from 40-200 Hz. (under the top panel)

B.M.S. (Bass management System) switch: Activates bass boost, which is centered according to the B.M.S. frequency setting.

• When used without a Kenwood head unit equipped with B.M.S. control:
  • The switch can be set to Open/Close, in which case the bass will not be boosted and the slide panel is opened by using the top open/close switch.
  • If set to the B.M.S. +6 position, 6dB of bass boost will be applied, and the slide panel is controlled manually by using the open/close switch. 
• When used with a compatible Kenwood head unit with B.M.S. control, the amount of bass boost (flat/6dB/12dB) and the opening and closing of the slide panel are controlled from the head unit.   Note that compatible head units can control up to three B.M.S. amplifiers.
  • When the switch is set to the Remote Open/Close position the bass cannot be boosted, but the panel can be opened or closed. 
  • When set to the Remote B.M.S. position, any of the three bass boost settings (flat/+6dB or +12dB) can be selected from the head unit.  If +6 or +12  is selected, the fan comes on and the slide panel automatically opens. 
  • When set to B.M.S. (+6), the bass is automatically boosted by +6dB, regardless of the control settings selected on the head unit.

B.M.S. frequency control: A variable control that allows you to adjust the center frequency at which Bass Boost (if used) operates.  It It may be varied from 50-100 Hz. (under the top panel)

Open/Close button: Opens or closes the sliding top panel.

Indicators

Cooling fan LED: Blinks when the cooling fan is activated due to temperature or when the top panel is opened, which automatically activates the fan

Operation/protection LED: Glows when power is on, goes out or blinks when the protection circuitry is activated

Low voltage LED: Illuminates when power voltage falls below 11 volts.  If  the power returns to a normal level, this LED will blink to alert user to the fact that a drop occurred.  The number of blinks will indicate how often the power dropped below 11 volts up to a maximum of 10 times.

B.M.S. LED: Illuminates when bass boost is turned on.  Note that if this LED and the cooling fan LED light up in succession or blink at the same time it means that the unit is in DEMO mode (which can be canceled by pushing the open/close button).

Power LED: A large blue LED shaped like a Kenwood logo; illuminates when power is on.

Inputs/outputs

• Left and Right gold plated RCA inputs are used for pre-amp connection.

• RCA preamp outputs: Gold plated RCA left and right jacks; this is a pass through, not controlled by the internal crossover settings.

• Power and Ground Inputs are gold plated terminal strip connections.

• Gold plated terminal strip connections for RCA cable ground, remote turn on and External Amp control (used to remotely control the B.M.S. function when this unit is used with a compatible B.M.S. control equipped Kenwood eXcelon head)

• Sigma Servo Feed Back Inputs are gold plated terminal strip connections.

• Speaker outputs are through gold plated terminal strip connections.

More specs and notes

Maximum power output: 1200 x 1

Rated power at 12 volts:

• 200 watts x 1 (4 ohms, 20Hz-20kHz, 0.05% THD)
• 400 watts x 1 (2 ohms, 1kHz, 0.5% THD)

Rated power at 14.4 volts:

• 300 watts x 1 (4 ohms, 20Hz-20kHz, 0.05% THD)
• 600 watts x 1 (2 ohms, 1kHz, 0.5% THD)

Best frequency response: 5Hz to 50kHz, +0/-3dB

Four 15 amp blade fuses are used for protection

The fan grille is under the top panel.