Class D Amplifier Design: The Kicker KX400.4 is a full-range
Class D amplifier, which uses digital switching to amplify audio signals. This
design results in high efficiency and less heat. The Class D design also allows
the KX400.4 to have a small footprint for increased cargo space.
CEA-2006 Compliant: CEA-2006 is a system of testing and
measurement methods for mobile audio amplifiers. This voluntary standard advocates
a uniform method for measuring an amplifier's RMS power output and signal-to-noise
ratio. The criteria for measuring power uses a DC input voltage of 14.4 volts and
the RMS power output is measured into a 4Ω load, with 1% or less Total Harmonic
Distortion plus noise (THD+N), and over a frequency range of 20 Hz to 20 kHz (for
full range amplifiers). Signal-to-Noise ratio is measured in weighted absolute
decibels (dBA) at a reference of 1 watt into 4Ω. CEA-2006 allows consumers
to compare car amplifiers and receivers on an equal basis. Using CEA-2006 criteria,
the Kicker KX400.4 is rated at 50 Watts RMS x 4 channels with a 75 dBA signal to
Specifications: The manual also lists these non CEA-2006
- 2Ω: 100 watts x 4 channels (no
more than 1% THD+N, 14.4 volts)
- Bridged: 200 watts x 2 channels (into
4Ω with no more than 1% THD, 14.4 volts)
- Signal to Noise Ratio: 95 dB (at rated
Kicker Livin' Loud Certified Power: The amplifier comes with
a certificate that indicates the total maximum RMS power output of the particular
amplifier, along with the model number, serial number, and whether the amplifier
passed the total harmonic distortion, signal-to-noise ratio, and protection
Auto Turn-On: The Auto Turn-On switch offers three options:
- +12 V: The amp turns on when +12 volts
is applied to the remote terminal.
- DC Offset: The amp turns on when a 6 volt
offset is detected on the signal inputs (from a speaker-level
source); in this mode the amp's remote terminal acts as a +12
volt output to turn on another component.
- Audio: The amp turns on when an incoming
audio signal is detected; in this mode the amp's remote terminal
acts as a +12 volt output to turn on another component.
Protection Circuitry: The KX400.4 has protection circuitry
that will turn the amp off in the event of overheating, over voltage (power input),
under voltage (power input), short circuit (speaker output), and over current
(speaker output). If the Protection LED on the front side of the amp illuminates
red, the protection circuit has engaged and the amp will not play until the problem
Gain: To accommodate the varying range of signal levels coming
from today's factory and aftermarket radios, the Kicker KX400.4 features adjustable
gain controls (low level: 125mV-5V, high level: 250mV-10V). The front and rear
sections of the amplifier (Amp 1 and Amp 2) have independent rotary gain controls,
labeled from 0 to 11.
Input Level Switch: Set the input level switch to Lo when using
preamp level input signals and Hi when using speaker level input signals.
Crossover: The front and rear sections of the amplifier also
have independent crossover circuits:
- Amp 1:
- Mode: three position switch;
Off (crossover bypassed), HP (high-pass), or LP (low-pass)
- Range: two position switch; sets the frequency
adjustment range for the crossover point dial; 1x (10-500 Hz) or 10x
- Frequency: continuously
variable from 10 to 500 Hz (with Range switch in the 1x position) or
100-5,000 Hz (with Range switch in the 10x position)
- Amp 2:
- Mode: four position switch; Off (crossover
bypassed), HP (high-pass), LP (low-pass), or BP (band-pass, both
high-pass and low-pass circuits engaged)
- Range: two position switch; sets the frequency
adjustment range for the low-pass crossover point dial; 1x or 10x
- High-Pass Frequency: continuously
variable from 10 to 500 Hz
- Low-Pass Frequency: continuously
variable from 40 to 500 Hz (with Range switch in the 1x position) or
400-5,000 Hz (with Range switch in the 10x position)
Fader: When your source unit has discrete front and rear
outputs, set the fader switch to on. Turn the fader switch off to send a single
stereo input to both the front and rear amps.
KickEQ: The amplifier's KickEQ bass boost circuits are
continuously variable from 0 to +18 dB and centered at 40 Hz. The front and
rear amps have separate bass boost controls.
Power Connections: The power and ground connections are
set-screw terminals that will accommodate up to 4-gauge wire. The remote turn-on
set-screw terminal will accept up to 8-gauge wire. The included Allen-wrench is
required to loosen/tighten the terminals.
Note: The Amplifier is not equipped with
an internal fuse. An external 80-amp fuse (not included)
must be installed on the power wire. If the system has
only this amp and a wiring kit is used that includes a
fuse with a value other than 80-amps, the original should
be replaced with an 80-amp fuse.
Speaker Outputs: The Kicker KX400.4 is equipped with four pair
of set-screw terminals. The terminals will accommodate up to 8-gauge wire and are
loosened/tightened with the included Allen-wrench.
Dual Sensitivity Inputs: The KX series amplifiers have dual
input sensitivity differential RCA inputs, which will accept either speaker-level
(high) or RCA (low) signals from your car's head unit. A high-level signal can be
run from the head unit's speaker outputs to the stereo RCA inputs of the amplifier
using Speaker Wire to RCA adapters
sold separately). The Input Level Switch on the amp should be set to high when
using a speaker-level input, and low when using an RCA line-level input.
Line Level Output: The amplifier has a pair of RCA line level
outputs for feeding another amplifier. This is the same signal that is present at
the amp's inputs. Either input method (speaker-level or RCA) will provide a low-level
output signal to the RCA outputs. The amplifier's crossovers have no effect on the
line level output signal, however, if you input a filtered signal from the head unit,
the amp's low-level output will also be filtered.