Sundown Audio SDX 400.1 User manual

Mono Blocks:
SDX 400.1
SDX 800.1
SDX 1200.1
Multi - Channel
SDX 90.2
SDX 100.4
SDX 200.2
SDX 100.6
This manual is intended to be a guide, installation by a qualified professional is recommended

SDX SERIES AMPLIFIER OWNER’S MANUAL version 07/21 v2
 Digital Class-D Mono Block Amplifier
 Dual MOS-FET PWM Power Supply
 1 Ohm Stable Load
 12 dB/Octave - Variable Low Pass Filter
 DC Auto sense feature
 0 to 12dB - Variable Bass Boost
 4 Way Protection Circuit (Thermal,
Voltage Speaker short and DC Offset)
 Wired Remote Control
Tested @14.4Volts SDX 400.1 SDX 800.1 SDX 1200.1
1Ω Mono RMS 400W 800W 1200W
2Ω Mono RMS 300W 550W 825W
4Ω Mono RMS 175W 315W 450W
Recommended Fuse Rating 40A 80A 120A
LoW Pass Filter
(-12dB/8) Variable 50hz-250hz
Input Sensitivity 6V Max
Signal Noise Ratio 90dB 87dB 83dB
Working Voltage 11.5V - 15V
Width mm 102 178 178
Length mm 147 226 312
Height mm 54 54 54
Width inches 4 7 7
Length inches 5.75 8.875 12.25
Height inches 2.125 2.125 2.125
DIGITAL MONOBLOCK FEATURES
DIGITAL MONOBLOCK
SPECIFICATIONS

SDX SERIES AMPLIFIER OWNER’S MANUAL version 07/21 v2
 High Efficiency Digital Multi-Channel
Design
 12dB/Octave-Variable High Pass Filter
 12dB/Octave-Variable Low Pass Filter
 DC Auto sense feature
 4 Way Protection Circuit (Thermal,
Voltage Speaker short and DC Offset)
 Optional Wired Remote Control
Tested @14.4Volts SDX 90.2 SDX 100.4 SDX 200.2 SDX 100.6
4Ω RMS bridged 240W 270Wx2 560W 300Wx3
2Ω RMS 120Wx2 135Wx4 280Wx2 150Wx6
4Ω RMS 90Wx2 100Wx4 200Wx2 100Wx6
Recommended
Fuse Rating
25A 50A 50A 80A
Low Pass Filter
(-12dB/8) Variable
30hz -
500hz
ch3/4 30hz -
500hz or 600hz
- 10khz @20x
20hz - 500hz
(ch5/6 30hz - 500hz) (ch3/4
30hz - 500hz or 600hz - 10khz
@20x) (ch1/2 15hz - 500hz or
300hz - 10khz @20x)
High Pass Filter
(-12dB/8) Variable
15hz -
500hz
ch1/2 15hz -
500hz or 300hz
- 10khz @20x
ch3/4 15hz -
500hz
20hz - 500hz
ch1/2 15hz - 500hz or 300hz -
10khz @20x ch3/4 15hz -
500hz
Input Sensitivity 6V Max
Signal Noise Ratio 78dB
Working Voltage 11.5V - 15V
Width mm 105 178 178 178
Length mm 148 226 226 312
Height mm 54 54 54 54
Width inches 4.125 7 7 7
Length inches 5.825 8.875 8.875 12.25
Height inches 2.125 2.125 2.125 2.125
FULL RANGE
DIGITAL
SPECIFICATIONS
FULL RANGE DIGITAL
FEATURES

SDX SERIES AMPLIFIER OWNER’S MANUAL version 07/21 v2
Some features not available on all models
PWR/PRT led: Power LED, it will be blue if it’s on, and your good, if its off, you’re not good. See the
troubleshooting section if it doesn’t turn on. Protect, if the LED is red, then the amp is in protect mode, see the
troubleshooting section for assistance.
POWER (B+, REM, GND): Connection for power source, see the Power Connections page for details
CH1-CH6 SPEAKER OUTPUTS: This is where your speakers plug in, see the amp specific
diagrams for assistance.
AUTO SENSE: What signal are you using to turn on the amp.
SIG: Detect signal from the HI-LEVEL inputs.
OFF: Turns off auto sense when using the REM (remote) turn on option.
DC: Turn on with B+, usually used in installs where the battery/power is disconnected when not in use
REMOTE: Plugin for the external bass knob, used to attenuate the from lowest point to the highest that was
set on the amplifier
5/6 CH INPUT, 3/4 CH INPUT: Duplicates the signals from CH1 and CH2 to CH3/CH4 and
CH5/CH6. Press the button in to duplicate, do not use the inputs on CH3/CH4 or CH5/CH6 if using this
feature.
CH1-CH6 RCA’s: RCA signal from source
OUTPUT RCA: Passthrough output to a secondary amplifier
Hi-Level In: Input for high level signals, do not use RCA’s when using these inputs
WHAT DO ALL THE SWITCHS, KNOBS AND LIGHTS DO?

SDX SERIES AMPLIFIER OWNER’S MANUAL version 07/21 v2
LEVEL/GAIN: NOT A VOLUME KNOB, THE INTERNET IS LYING TO YOU
😊, used to set the input signal levels, start from Min and slowly turn clockwise
until you hear angels singing or the sirens from the cops looking for you. Scan this
QR Code for a video on setting your gains
FILTER: Turns the internal crossover on or off, you typically would not turn it off
unless you have an external processor or crossover. Turning these off without
external protection could damage your speakers
RANGE: Multiplier for the crossover point for the LPF and HPF knobs, x1 will indicate the top frequency
range, x20 will indicate the bottom range.
LPF: Low pass filter – Filters out high frequencies
HPF: High pass filter - Filters out low frequencies
SUBSONIC: Filters out low frequencies on the lower spectrum, this is used to protect subwoofers from
playing frequencies lower than they were designed to handle.
PHASE- Turn to adjust the phase. Can be used on 180 when inverting woofers.

SDX SERIES AMPLIFIER OWNER’S MANUAL version 07/21 v2
+12V Battery
You need to connect a power wire to the vehicle’s positive battery terminal. This connection must be tight and
secure to ensure proper connectivity. This wire has to be fused appropriately (see each amplifier’s fuse rating
under specifications) within 12 to 16 inches for safety. You will then need to connect the power wire to the B+
terminal of the amplifier with a Phillips screw driver. Do not install the fuses until installation is complete.
Ground Connection
It is recommended that you connect your ground directly to your power source ground for the best possible
performance. However, if you cannot, then the ground connection must be made to the vehicle’s chassis and
should be kept as short as possible, while accessing a solid piece of sheet metal in the vehicle. The surface
should be sanded at the contact point to clean rust, paint or grime so a metal-to-metal connection between the
chassis and the termination of the ground wire is effective. You will then need to connect the ground wire to the
GND terminal of the amplifier.
Remote
The +12V remote turn-on wire is typically controlled by the source unit’s remote turn-on output. The amplifier
will turn on when +12V is present at its remote (REM) input and turn off when +12V is switched off. Connect
the remote wire using 12 to 16-gauge wire to the REM connection of the amplifier, then connect the other end
of the remote wire to either the source unit’s turn on output or ignition switch circuit. The models that have the
extra power input will have an extra REM connection noted as OUT, this is intended to allow you to connect
your REM line to other devices if needed.
WARNING
The SDX Line of amplifiers do not come with external fusing.
Make sure you install appropriate in line fusing from the
positive side of your power source.
POWER CONNECTIONS

SDX SERIES AMPLIFIER OWNER’S MANUAL version 07/21 v2
MONOBLOCK INPUT AND SPEAKER CONNECTIONS
B+
REM GND
POWER
PWR
PRT
INPUT
R R
OUTPUT
L L
SPEAKER OUTPUT

SDX SERIES AMPLIFIER OWNER’S MANUAL version 07/21 v2
MULTI CHANNEL FULL RANGE INPUT AND SPEAKER
CONNECTIONS
B+
REM GND
POWER SPEAKER OUTPUT
CH 1CH 2
SPEAKER OUTPUT
CH 3CH 4
SPEAKER OUTPUT
CH 5CH 6
PWR
PRT
CH1
CH2
CH3
CH4
CH5
CH6
5/6 CH
INPUT INPUT
3/4 CH
CH 1|2
CH 5|6
CH 1|2
CH 3|4
AUTO
SENSE
OFF

SDX SERIES AMPLIFIER OWNER’S MANUAL version 07/21 v2
Bridge mode examples for Series and Parallel wiring
MULTI CHANNEL BRIDGE MODE INPUT AND SPEAKER
CONNECTIONS
B+
REM GND
POWER SPEAKER OUTPUT
CH 1CH 2
SPEAKER OUTPUT
CH 3CH 4
SPEAKER OUTPUT
CH 5CH 6
PWR
PRT
CH1
CH2
CH3
CH4
CH5
CH6
5/6 CH
INPUT INPUT
3/4 CH
CH 1|2
CH 5|6
CH 1|2
CH 3|4
AUTO
SENSE
OFF

SDX SERIES AMPLIFIER OWNER’S MANUAL version 07/21 v2
Bridge mode example using a Dual Voice Coil Subwoofer
BRIDGE MODE INPUT AND SPEAKER CONNECTIONS
B+
REM GND
POWER SPEAKER OUTPUT
CH 1CH 2
SPEAKER OUTPUT
CH 3CH 4
SPEAKER OUTPUT
CH 5CH 6
PWR
PRT
CH1
CH2
CH3
CH4
CH5
CH6
5/6 CH
INPUT INPUT
3/4 CH
CH 1|2
CH 5|6
CH 1|2
CH 3|4
AUTO
SENSE
OFF

SDX SERIES AMPLIFIER OWNER’S MANUAL version 07/21 v2
Subwoofer planning
When using more than one subwoofer, you have to make sure your total impedance does not go below the
minimum level of the amp, see the specification charts for your amplifier’s minimums. Use the chart below to
help in your design.
Coil Impedance
D
4
D
2
D
1
Number of dual
coil subwoofers
2
4.00
2.00
1.00
3
2.67
1.33
0.67
4
2.00
1.00
0.50
5
1.60
0.80
0.40
6
1.33
0.67
0.33
7
1.14
0.57
0.29
8
1.00
0.50
0.25
Safe for use where the minimum
impedance is 2Ω and up
Safe for use where the minimum
impedance is 1Ω and up
DO NOT USE
Impedance is too low
SERIES/PARALLEL WIRING OF DUAL COIL SUBWOOFERS

SDX SERIES AMPLIFIER OWNER’S MANUAL version 07/21 v2
PARALLEL WIRING OF DUAL COIL SUBWOOFERS
SERIES WIRING OF DUAL COIL SUBWOOFERS

SDX SERIES AMPLIFIER OWNER’S MANUAL version 07/21 v2
Your new Sundown Audio amplifier is covered by a 2-Year limited warranty if purchased from an authorized
Sundown Audio dealer. This warranty does not cover improper installation, accidental damage, misuse, abuse,
improper wiring, operation of unit outside of listed specifications, or any product that has been modified or
repaired by anyone other than Sundown Audio. Your warranty covers defects in materials and/or workmanship
ONLY and is not an insurance policy. The warranty only covers the original owner of the amplifier.
All warranty returns must be accompanied by the original sales invoice or receipt. You must contact us to
request an RMA number prior to sending any returns via the RMA request form on our web-site. During the
RMA number process, we will generate a pre-paid FedEx label for your return. If your amplifier is covered
under warranty shipping both ways will be at no cost to you – if your amplifier is replaced/repaired outside of
warranty or if no defect is found and your product must be return to you shipping both ways will be billed to
you.
At the sole discretion of Sundown Audio your amplifier will be either repaired or replaced when it is being
covered under warranty. In the event of shipping damage due to improper packaging on products being
returned to Sundown Audio the customer is liable for the cost of all damages, necessary repairs, or
replacement. Be sure to properly pack your return!
Sundown Audio also offers a 5-Year “discounted replacement” policy on all of our amplifiers. We are so certain
of the quality of our equipment that even if you are at fault for causing damage to your amplifier we will offer
you a new unit at a reduced cost for a full 5-years from your purchase date. Contact us via our RMA form to
take advantage of this offer. This offer applies only to the original purchaser of the unit and is not transferable.
As is the case with standard warranty claims the return must be sent with a copy of the original invoice or
receipt.
In no event will Sundown Audio be liable for incidental, consequential, or other damages resulting from the use
of this product, this includes but is not limited to, damage of hearing, property or person, damage based upon
inconvenience or on loss of use of the product, and to the extent permitted by law, damages for personal
injury. This warranty gives you specific legal rights, and you may have other rights, which vary from state to
state. This warranty applies only to products sold and used in the United States of America. In all other
countries please contact your local distributor.
WARRANTY

SDX SERIES AMPLIFIER OWNER’S MANUAL version 07/21 v2
All Sundown Audio amplifiers have multi-layer protection features to prevent damage from misuse or faulty
conditions to ensure long lasting life of your investment. If the unit senses excessive heat, short circuited
speakers, overload, or voltage fluctuation outside of the working range the protection indicator light will turn red
and the unit will turn off. In order to solve this problem, you should turn all levels down, power off the unit, then
carefully check the installation for wiring mistakes or shorts. If the amplifier is excessively warm the protection
light will not turn on as the unit will turn off to protect itself from overheating. Let the unit cool down for 30
minutes and try again. If the unit works, try moving the amplifier or make sure nothing is covering it so it can
vent heat off of the heatsink. Before you remove or uninstall the amplifier, refer to the list below for suggested
solutions.
Amplifier Doesn’t Turn On or No Output
 Check the fuse(s), not just visually, but with a continuity meter and all 12+ volt, remote and ground
connection. Make sure you have 13+ volts. It is possible for a fuse to have poor internal connections,
take the fuse out of the holder for the testing.
 Check the input signal from the source unit using an AC voltmeter to measure the voltage while it’s
being played. The voltage should be from 0.2 to 6.0 volts from the RCA cables.
 Check the output of the amplifier, test for output at the speaker outputs of the amplifier.
 Check to ensure that the speaker wires are making a good connection to the amplifier and the
subwoofers.
Amplifier Goes Into Protection
 Check shorts on speaker wires or open coil.
 Check input voltage from RCA, if DC signal is over 4 volts, the amplifier will go into protect. Remove
and reset the power to the unit to check if it will turn on.
 Check impedance to make sure it’s over the minimum load, see the specification charts in this manual
for the minimums of your specific amp.
 Check input voltage. The amplifiers covered in this manual have a working range of 10.5 to 15 volts.
 Check chassis ground and remote using same ground.
Distorted / Attenuated / Noise Sound
 Check the chassis ground connections of all audio equipment.
 Check amplifier controls for errors, input level or crossover setting.
 Check the speaker wires for a possible short, either between the positive and negative leads or
between a speaker lead and the vehicle’s chassis ground.
 Check the nominal load impedance to verify that the amplifier is driving a load equal to or greater than
the specified minimums, see the specification charts in this manual for the minimums of your specific
amp.
 Check the input signal and input signal cables to make sure signal is present at the amplifier inputs and
the cables are not pinched or loose. It may be helpful to try a different set of cables and / or a different
signal source to be sure.
 Check speaker wiring for reverse polarity.
 If you hear a pulsing sound from your speakers, it means that there is something being overdriven.
This could be due to a gain being set too high or a speaker impedance being too low, see the
specification charts in this manual for the minimums of your specific amp.
TROUBLESHOOTING

SDX SERIES AMPLIFIER OWNER’S MANUAL version 07/21 v2
514 W 21st Street, Newton, NC 28658
[phone]
Find us on:
WWW.SUNDOWNAUDIO.COM