How to install and
operate the DLS
Reference series
car audio mono
amplifier RA10.
Tools and materials needed……….
Amplifier installation kit…………....
Routing Wires……………………....
Power connection..……………..….
Input and controls……………….....
Input wiring.....................................
Input level control..........................
Grand Bass..................…………....
Phase control.................................
RA10 speaker wiring:
One subwoofer…...………………....
Two subwoofers...…………………...
Four subwoofers...............................
This owners manual is written in easy english and
uses a lot of drawings to simply the installation and
use of the above amplifiers.
Installation with two subwoofers:
Wiring example.............................. ..
Professional tips……………………..
Your DLS amplifiers must be installed correctly in
order to work well. This manual will show you how
to install the amplifier like a pro. Please read the
entire manual before beginning the installation.
Install the amplifier yourself if you feel confident with
our instructions and if you have the proper tools.
However if you feel unsure, turn over the installation job to someone better suited to it.
Warranty Service
This amplifier is covered by warranty, depending
on the conditions in the country where it is sold. If
the amplifier is returned for service, please include
the original dated receipt with the product.
Technical Assistance
For technical assistance ask the shop where the
product was sold or the distributor in your very country.
You can always phone the DLS Helpdesk in Sweden
+ 46 31 84 00 60 or send an e-mail to
Information can also be found on our WEB-site
The amplifier include
RCA inputs
High Level input
Variable low pass crossover
Subsonic filter
Grand bass feature 0 - +18 dB
Phase shift continously variable 0-180 degr.
Remote bass level and phase shift control
Remote turn on / off
Automatic remote turn on/ off on high level
input without connecting any remote wire
Built-in cooling fan
Electronic protection circuitry against
short-circuit, DC offset and thermal overload.
Before you begin installation
Before you begin you need to read the manual, to have
some tools, cables and other material available. There
is one such list of material on the following page.
Disconnect Battery
Before starting the installation, always disconnect
the negative terminal of
the battery.
Amplifier location
Allow air circulation around the amplifier.
The DLS Reference series of amplifiers have a
compact design that allows great flexibility in
mounting. You can mount it under a seat or in the
trunk. When you select a location, do remember
that the amplifier generates a lot of heat.
Choose a location where air can circulate freely
around the amplifier. Do not cover the amplifier
with carpets or hide behind trim panels.
Do not mount the amplifier in an inverted or upside
down position. The amplifier has a built-in fan
in the bottom plate. Mount the amplifier on
spacers to allow the air to circulate inside the
Check all locations and placements carefully
before making any cuts, drilling any holes or making any connections.
This is the best direction to
mount the amplifier in order
to get the best cooling.
DLS logo on amplifier cooling flange
The DLS logo on top of the amplifier is attached
with two hex. screws. The logo can be removed
and twisted 90 or 180 degrees, and then screwed
back in wanted position. The logo can be mounted
in four different ways to match your installation.
Tools and material needed
Flat and Phillips screwdrivers
Wire cutter
Wire stripper
Electric drill with drills
Crimping tool
Digital multimeter or test lamp
Wire brush, scraper or a piece
of an abrasive sheet to remove
paint for a good ground connection
Grease to protect the ground
connection from oxidation
Routing wires
head unit
Speaker wire: minimum
12 AWG = 4 mm2 for subwoofer connection
Sheet metal screws for mounting the
amplifier to the amplifier board and the
amplifier board to the car + some extra
for fuse holder, amplifier ground etc.
Electrical insulation tape
½ inch thick plywood or particle board for
the amplifier to be mounted upon.
Amplifier installation kit:
If available,buy an amplifier installation kit. It
contains normally all you need. This is what you
have to buy if you buy the items separately
20- 25 feet = 6- 7.5 meter power cable,
4 AWG = 21 mm2 or heavier.
1 pc of fuseholder to install close to the
car battery + fuse 100 Ampere (for 4AWG
power cable).
20 feet of 15 AWG = 1,5 mm2 wire for
remote turn on / off cable from radio.
RCA-cable for input from radio.
- 20 feet or 5 meter for trunk installations
-12 feet or 2 – 3 meter for under seat
Two ring crimp terminals –one
for connection to the battery plus and one
for the amplifier ground connection.
Four splicers to connect speaker
cables to high level input cable, if high level
input is used.
Wire ties
Insulating grommet or insulating tube
Professional Tip:
Professional Tip:
If amplifier installation kits are available with different size of power cable, chose the most heavy
power cable to improve sound quality and to allow
more amplifiers to be installed now or later.
If possible use 4 AWG = 21 mm2 cable for best
performance. This is for cable lengths up to 5 meters. The ground cable must have the same size.
Max fuse values for different cable sizes:
6 mm2 (9 AWG) :25 A
16 mm2 (5AWG) :60 A
33 mm2 (2AWG) :150 A
10 mm2 (7AWG) :40 A
21 mm2 (4AWG) :100 A
42 mm2 (1AWG) :200 A
Gauge (ga) is an American measure for cable size,
also called AWG (American Wire Gauge).
0 AWG = 50 mm2
1 AWG = 42 mm2
2 AWG = 33 mm2
3 AWG = 27 mm2
4 AWG = 21 mm2
5 AWG = 16 mm2
6 AWG = 13 mm2
7 AWG = 10 mm2
8 AWG = 8 mm2
9 AWG = 6,8 mm2
10 AWG = 5,3 mm2
11 AWG = 4,2 mm2
12 AWG = 3 mm2
13 AWG = 2,7 mm2
14 AWG = 2 mm2
15 AWG = 1,65 mm2
16 AWG = 1,3 mm2
Power connections
Power terminal ( +12V)
Remote terminal ( REM )
Connect the fuse holder as close to the vehicle
battery + as possible, using 4 AWG = 21 mm2 or
heavier cable. Use ring crimp terminal cable to
connect to battery +. Apply silicon grease to the
fuse to prevent corrosion.
Use a 100 Amp fuse for cable
4 AWG (21 mm2).
RA10 accepts 4 AWG
(21 mm2) in the power
Connect with ring
terminal to
battery + terminal
fuse holder
Connect the battery cable from the fuse holder to
the +12 Volt terminal on the amplifier.
Be sure to use a rubber grommet or a plastic
insulating tube where the cable passes the firewall
or other places when it can easily be jammed.
Use ty-wraps to secure to existing cables in the
engine compartment.
Ground Terminal ( GND )
Connect to a good chassis ground. The ground
connection should be clean, unpainted metal to
provide a good electrical connection. Use a wire
brush, a scraper or a piece of an abrasive sheet to
clean the metal. Use a lock washer or two to secure
contact. Protect with silicon grease or by paint
applied afterwards.
For RCA cable signal input:
Set the input selector switch to position ”Low level”.
Connect the radio power antenna lead = remote
turn on/off from the car stereo to the amplifier
remote connection. This turns on the amplifier
whenever the car stereo is turned on.
You can either use the built in remote cable in the
RCA cable itself or use a separate cable.
Sometimes a small disturbance may enter the
amplifier coming from the remote voltage , through
the built in remote wire and into the RCA cable.
Thus we recommend to use a separate remote wire
and run the RCA lead separate from remote wire,
power cables and speaker cables.
Insert the cable directly into the amplifier terminal.
If there is no remote voltage available from the stereo, you must connect to the ignition key through
the radio or any accessories fuse.
Set the ”High level auto
start” switch to position
Connect to head
unit remote start
terminal or power
antenna lead
For High Level input:
Set the input selector switch to position ”High level”.
We recommend you to connect the remote wire as
described above. The amplifier will produce soft
on / soft off operation this way. If you use a remote
wire, set the switch ”High level auto start” to position OUT.
In the case that there is no remote voltage available
from the car stereo, or you want to simplify the installation, the amplifier can be turned on/ turned
off by the high level input voltage. This is done
when the ”High level auto start” switch is set to IN
- position.
Connect with ring
terminal to
chassis ground
Fuses on amplifier
Power Light / Protect light
Use only four 30 ampere ATC
blade type fuses.
30 A
The power light (green ) comes on when
the amplifier is turned on.
The protect light ( red ) comes on
when the amplifier shuts down from
overheating, DC-offset or a short
circuit ( speaker failure)
Input and controls
Input Wiring
Inputs may be low level from the RCA output of the
car stereo, or high level from the car stereo speaker
output. Low level = RCA is to prefer for the best sound
Low level input
Use a pair of shielded stereo audio cables with RCA
type jack. Most trunk-mount amplifiers need a 20
feet RCA cable ( appr 5 – 6 meters). Most under
the seat installations require 12 feet ( 2 – 3 meters)
RCA cables. Avoid placing the RCA cable close to
speaker cables, power cables and remote control
cable. Connect to RCA input
sockets. Both inputs must be
connected. Use a Y -split if
Set the input selector switch
to position ”Low level”.
High Level Input
Connect left and right speaker wires coming from
the car stereo to the high level input as shown. You
must connect both plus and minus as the inputs
are balanced, connecting plus only gives lower level
and bad sound quality. By changing the polarity of
plus and minus, you can change the phase.
High level input socket
Right Left
Hi level input
socket on amp.
Green: Left +
Black: Left Black: Right Grey: Right +
Hi level input plug.
High / Low level input switch
To ensure best possible performance from the
amplifier a switch is installed to select between
High and Low input.
When using High Level input:
Push in the button to position
”High Level”
When using Low level input:
Push out the button to position
”Low Level”
Hi level auto start switch
To ensure best possible performance from the
amplifier when used with high level input a switch
is installed to select between Automatic amplifier
start and remote wire start.
When using High Level input with
automatic start:
Push the button to position IN
When using High level input with
remote wire start:
Push out the button to position OUT
Some head units use BTL output IC:s that have a
constant 6-12 Volt + on the speaker terminal, also
when shut off (the Power LED indicator lights
constantly even when the head unit is off). In this
case you have to use a separate remote wire
connected to the REMOTE-terminal instead.
Automatic turn on when using high level input.
With the ”Input selector switch” set to High level
and the ”High level Auto Start” switch set to IN,
the amplifier turns on automatically on high input.
You don´t need to connect a separate remote wire
from your head unit.
If you want to use high level
input but use a remote start wire, just set the ”High
level Auto Start” switch to OUT.
Input Level control
The input level control, 8V – 0,5 V,
matches the output of your radio to
the input of the amplifier. After installation is complete, make sure
the input of the amplifier is turned
8V 0,5V
down all the way ( counterclockwise at 8V ).
Play a tape or CD, make sure all bass or treble
settings or equalizer are flat, and turn the volume
of the radio up until you just start to hear distortion.
Turn the volume control down just a bit. On the
amplifier increase the input level control ( clockwise
or to the right ) until you just start to hear distortion,
then back the level control just a bit. Now your radio and amplifier levels are matched.
Grand bass 40 Hz
- LP-filter 40 - 125 Hz, slope 12 dB / octave
- Subsonic filter 25 Hz fixed frequency, slope 18 dB /
octave. The subsonic filter can be switched off.
Low Pass Filter
The LP-filter ( low pass filter) is
used for subwoofers. It will allow
low frequencies only and blocks
higher frequencies.
A typical setting is 50 – 80 Hz.
40 125
Subsonic filter
Grand Bass is used to increase the bass volume
with a center frequency of 40 HZ. You can select
the amplification between 0 dB ( no amplification )
and +18 dB (full amplification).
This function is used to
compensate for the bass box
function and to adjust for your
own taste of bass. Set level
control at 0 dB if you want it
to be inoperative.
Phase control
The phase control can be set
continuously from 0 - 180
degrees. This is very useful when
you want to adjust the bass
sound for best front stage image.
Start on 0 and turn the control
slowly clockwise until you
experience that the bass sound
is coming from the front. If you
dont get the result you want, also
try to phase reverse the
subwoofer connections and
make a new adjustment. You can
also adjust the phase from the
front seat by using the Remote
bass level and phase control
The DLS Reference amplifier RA10 include low pass
filter (LP) and subsonic filter.
0 180
The subsonic filter is used to take
away the very deepest
frequencies from a bass box.
The x-over frequency is 25 Hz.
Remote bass level and phase control box
The amplifier includes a remote control unit. With
this unit it is possible to adjust the bass level and
phase from the front seat. Connect the cable
between the amplifier socket and the socket on the
remote box. Activate the remote control box by
pushing the switch to position IN.
Speaker wiring RA10
RA10 is a mono amplifier made for use with subwoofers
only. The amplifier has two output connectors. These
are internally connected in parallel and are doubled
for easier connection when you have more than one
subwoofer. It is not possible to connect in bridge
mode between the speaker terminals.
One 4 ohm subwoofer connected (4 ohm load)
Four 4 ohm subwoofers connected (1 ohm load)
Two 4 ohm subwoofers connected (2 ohm load)
The amplifier is 1 ohm stable. This means that you
can connect subwoofers in various connections, in
parallel or in series, as long as the resulting
impedance is not less than1 ohm.
If you have subwoofers with dual 4 ohm voice coils,
connect the coils in parallel to get more power from
the amplifier.
LP-filter settings
40 125
The typical setting is around 60 – 80 Hz.
The subsonic filter should be in position IN.
Wiring example of RA 10 with two subwoofers
100 A
Battery 12V
4 ohm
4 ohm
RCA out
Remote bass
level and
phase control
Before you finish the installation, you should do the
following tests to make sure the wiring is correct and
everything is operating properly.
If problems occour during the installation, or later,
this guide might help you to find out whats´s wrong.
Reconnect Battery
When wiring is complete,
reconnect the battery
negative terminal.
Test power wiring
Turn on the head unit but do not turn up the
volume. The amplifier power light should
come on. If not, check the remote and +12
volt wires. Also check the ground
Turn up the head units volume slightly. All
speakers should operate. if not, check wiring
connections at amplifier and speakers.
Test speaker connections
Make sure the speakers are connected right. Use
the balance control on the head unit to make sure
right channel is on right speaker etc. If speakers
don´t play at all, one or both speaker wires may
be disconnected.
1. Check power lead, ground and remote
connections at the amplifier using a multi meter.
2. Check the battery terminal connections.
3. Check the power lead fuse or circuit breaker. If
fuse damage continues, inspect the power lead
for short circuits.
4. Check the amplifier protection fuses. Are these
broken change to new ones with the same value.
If short circuiting continues, contact your local
DLS dealer. A fault may exist in the amplifier.
5. To start the amplifier requires a remote voltage of
9-15 volt. Check the voltage with a multi meter.
1. One or more speaker cables are shorted. Make an
insulation test with a multi meter. The cables must not
have a connection to earth.
The amplifier is overheating due to inadequate ventilation. Check mounting position is free from obstruction.
Do this:
Move the amplifier to a place with better ventilation.
Make sure the internal fan is working and that
the amplifier is installed in a way that allows air
to circulate freely inside the amplifier.
Overheating can also be caused by an
impedance load below the level permitted.
Check the following:
Speaker cable connections to both amplifier and
Signal lead plugs and cables.
Professional Tip:
Professional Tip:
All speakers in a car audio system should be
connected in phase (the same polarity). All speaker cones must move in the same direction. Out of
phase speakers will cause a lack of bass, and a
poor stereo soundstage.
Do this:
Rewire the power supply (12 V) to source
unit direct from battery.
Rewire ground wire from source unit to
clean position on chassis.
Check all power connections to ensure that
they are clean and tight.
Check quality of system ground connection.
Install a Power Cap capacitor. This can be
helpful against most noise problems.
Do this:
Ensure that all equipment has a common
ground point.
Check quality of earth strap connection from
battery negative terminal to chassis.
Disconnect signal cables from amplifier to
see if noise disappears. If so the leads are
picking up noise. Test this by laying a new
cable over the seats and reconnecting to the
amplifier. If the noise does not return, reroute original cable away from source of
If noise remains regardless of cable position,
try to use so called Quasi-balanced signal
cables. DLS PRO-cables are
Professional Tip:
Installing in trunk
When installing the amplifier in the trunk, run the
power wires along the same path as the other
vehicle wiring. Many cars have insulated channels
for wiring. you will have to remove the door sill trim
and the carpet.
Checking polarity:
Hold the - connection of the speaker wire to the terminal of a 1,5 Volt flashlight battery. Tap the +
wire on to the + terminal of the battery, and observe
the movement of the cone. The cone should move
outwards when the wire touches the battery, and
inwards when the battery is removed. If it is the
other way around, the speaker has been connected
backwards and it must be removed and connected
If your system also has a subwoofer connected
through a passive 6 or 12 dB crossover, try to
connect this with various polarity and judge what
sounds best. The phase shift in passive crossovers
sometimes makes it necessary to change polarity.
1,5 Volt
NOTE! Tweeters can not be tested this way,
double check the connections instead.
Professional Tip:
Securing wires
Use wire ties to bundle together when possible.
(But never bundle speaker wires or signal cables
together with power wires.
Professional Tip:
Crimp connections
Purchase crimp connectors and crimping tool.
Connectors are color coded.
1. Strip 1/4 inch (6 mm) of insulation from the wire.
2. Insert into connector
3. Crimp tightly
Professional Tip:
Speaker and power wires
Do not run speaker and power wires next to each
other. Power wires can generate a ”siren” sound in
the speakers. Run speaker and power wires on
opposite sides of the car.
DLS Reference
Number of channels
Working mode
Power output at 13,8 Volt, max 0,1 % THD
Power output in 4 ohm
Power output in 2 ohm
Power output in 1 ohm
THD @1 W
Signal to noise ratio, A-weighted
Damping factor
Frequency response +/- 3 dB
Input impedance, low level
Input impedance, high level
High level input with auto start
Input sensitivity
Filter slope LP-filter
Filter slope subsonic filter
300 W
500 W
780 W
< 0,1%
>100 dB
10 Hz - 125 Hz
>10 kohm
330 ohm
0,5 - 8V
12 dB / octave
18 dB / octave
Pre amp configuration:
Filter lowpass
Fixed 25 Hz subsonic filter
Phase shift 0- 180 degrees continously
Grand bass adjustable gain @ 40 Hz
Remote bass level and phase control
* can be switched in/out
40 - 125 Hz
0 - 18 dB
Max cable size, DC input
Max cable size, speaker terminal
current, DC-offset & thermal
4 AWG, 21 mm2
7 AWG, 10 mm2
Power consumption:
Dimensions HxWxD(mm)
Dimensions (inch)
0,6 A
120 A
4 x 30 A
59 x 359 x 245
4,3 kg(9,5 lbs)
We follow a policy of continuous advancement in
For this reason all or part of specifications & designs
may be changed without prior notice.
DLS Svenska AB
P.O. Box 13029
SE-40251 Göteborg, Sweden
Tel: +46 31 840060
Fax: +46 31 844021