Soundstream Reference Series 705 User manual

1
REFERENCE 705
5/3 Channel
Power Amplifier
OWNERS MANUAL AND
INSTALLATION GUIDE

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CONGRATULATIONS!
You now own the REFERENCE705 Amplifier, the product of an uncompromising design and engineering
philosophy. Your Soundstream REFERENCE amplifier will outperform any other amplifier in the world.
To maximize the performance of your system, we recommend that you thoroughly acquaint yourself with its
capabilities and features. Please retain this manual and your sales and installation receipts for future reference.
Soundstream amplifiers are the result of American craftsmanship and the highest quality control standards, and
when properly installed, will provide you with many years of listening pleasure. Should your amplifier ever need
service or replacement due to theft, please record the following information, which will help protect your
investment.
Serial # _____________________________________________
Dealer’s Name _______________________________________
Date of Purchase _____________________________________
Installation Shop ______________________________________
Installation Date ______________________________________
CAUTION!
Prolonged listening at high levels may result in hearing loss. Even
though your new Soundstream Reference705 sounds better than
anything you’ve ever heard, exercise caution to prevent hearing

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TABLE OF CONTENTS
Features .........................................................................................................................4 -5
REFERENCE Power Supply Design....................................................................................6
Setting High Power/High Current.........................................................................................7
Selecting Crossover Modes.................................................................................................8
Selecting Input Modes.........................................................................................................9
Setting Coherent Stereo/Bridged Mono...............................................................................9
Wiring (with Diagram)........................................................................................................10
Installation and Mounting...................................................................................................11
Level Setting......................................................................................................................12
Crossover Adjustments......................................................................................................12
LSE.Q Subwoofer Equalization Circuitry ...........................................................................13
Sample Systems.........................................................................................................14 -17
Protection Circuitry & Troubleshooting ..............................................................................18
Service...............................................................................................................................19
Specifications ....................................................................................................................19

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DESIGN FEATURES
•Uncompromising Design and Construction including mil-spec glass epoxy circuit boards and
high current custom gold-plated solid brass connections that will accept up to 4 gauge power/
ground wire.
•High Power/High Current Capability (subwoofer channel only) -Soundstream’s exclusive circuitry
permits customization of your amplifier to its particular application—High Current, for ultra-low
impedance loads (multiple subwoofers, less than 1 ohm) or High Power, for higher impedance
loads (1 ohm and up).
•ChassisinkTM Darlington Power Array -Soundstream’s “overbuilding” of the output section
incorporates multiple output transistors instead of a few for faster, stronger power delivery. The
transistors are directly sandwiched between the circuit board and the heatsink in a design called
ChassisinkTM to ensure cool, efficient amplifier operation.
•Staggered Asymmetrical Electronic Crossover -Continuously variable 2 or 3-way crossovers
with 12 dB/octave high pass and 24 dB/octave subwoofer low pass. In 3-way mode, bandpass can
be selected for midrange or midbass.
•Rear Channel De-emphasis -A circuit based on theater surround technology in which rear fill
information is rolled off at 6 dB/octave with a -3 dB point at 7,000 Hz to provide a more realistic
Reference705
MONO
-ONE+MONO -TWO+LSE.QX-OVERLEVELINPUTS+L- - R++12vGND REMOTEX-OVERLEVELINPUTS+L- - R+X-OVERLEVELINPUTS
LRLRLR
0.7-2.8 17-60
Q
BOOSTHz FREQ
30-60
Hz
LP
2.5-0.04
VOLTS
240-960
1K-4K
Hz
(3-WAY)Hz HP
60-240
VOLTS
2.5-0.1 60-240 2.5-0.1
VOLTSHP
SUBWOOFER CHANNELS3+4CHANNELS1+2
Fault
High Power
High Current
Handcrafted intheU.S.A.
D E-
EMPHASIS
7KHzLP
6dB/Oct
INPUT
SELECTREAR FIL LXOVERXOVER
HIGHPASS
60-240Hz
HIGHPOWERHIGHCUR R ENT
SUBCHANNEL
3-W A Y*
MID
(1-4 KHz)STEREO
(NON-BRIDGEABLE)
CH1
60-240Hz
60-240Hz
240-960Hz
1-4KHz
CAUTION:D O NOTSWITCHWHEN A M PL IFIERISTURNED O N.
UseHIGHCURRENTfo rSUBCHANNELloadsatorbelow1ohm .
+L- - R+
SPEAKERCON N ECTIONDIAGRA M
CHANNELS1-4SUBCHAN NEL
+L- - R+-+-+
USERIG HTCHANNELINPUTSFOR
BRIDG INGCHANNELS1-4.
SUBCHAN N EL
BOTH SWITCHES SHOULDBEINTH ESA M EPOSITION
*In3-W A Yxovermode,CH1&2becomeHIGHPASS,CH3&4becomeBA N DPASS.

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listening experience (in 5 channel mode only).
•PowerGrid Power Supply Design -All power supply components are located near one another,
for the shortest possible current path and are connected by thick, wide PCB traces, which ensures
rapid, high current delivery. The entire power supply is isolated on one side of the circuit board
while the audio stage is located opposite it, guaranteeing minimal noise.
•Ultra-Low ESR Capacitance Bank -24 miniature “stiffening” capacitors ensure rapid power
delivery for dynamic peaks. Multiple small input power capacitors are used to provide a lower ESR
(Equivalent Series Resistance), which means more power, faster.
•Smart Thermal Rollback -Most amplifiers shut off when they get too hot. In the unlikely event the
Reference705 reaches 85° C, it will gradually roll back its average power (without affecting the
dynamics). Once the amplifier has cooled off, it returns to full power output. If overheating should
continue, a second thermal sensing protection circuit will shut off the amplifier if the heatsink
reaches 95° C.
•Unregulated Power Supply -4 ohm power ratings are measured at 12 volts, which means
substantially greater output in the real world when the vehicle is running, where voltages range
from 13.6 to 14.4 volts. Dynamic capability of the unregulated power supply is vastly greater than
that of a tightly regulated power supply.
•Fault Monitor LED on the front panel notifies you of a blown power supply fuse.
•1/2 Ohm Subwoofer Drive Ability -The Reference705 subwoofer channel is designed to be stable
into any impedance, down to 1/2 ohm.
•Six Dual Discrete Class A Drive Stages -Over six times the drive current of most amps, which
guarantees maximum performance into any load.
•Drive DelayTM Muted Turn-on/off Circuit -A unique circuit which completely eliminates amplifier-
related turn-on/off noises.
•Flexible Input Sensitivity accepts voltages from 100 mV (40 mV on the subwoofer channel) to 2.5
V, which permits maximum output from the amplifier with virtually any source unit.
•Balanced Input Design for added immunity to noise caused by component and vehicle electrical
system interaction.

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4 Ohm Sub Channel Watts
050 100 150 200 250
12 volts
14.4 volts
REFERENCE POWER SUPPLY DESIGN
The Reference705 employs an extremely efficient unregulated pulse-width modulated power supply.
Like the rest of the REFERENCE amplifiers from Soundstream, the Reference705 is rated at 12 volts
but is designed to take advantage of the additional voltage available when the vehicle is running.
The two major advantages of the unregulated power supply are:
•awesome dynamic power capabilities
•added continuous power with higher voltages (see chart below)
Because of the dynamic properties of most music, all audio components should be able to react
accordingly. Thanks to its unregulated power supply, the Reference705 can comfortably exceed its
rated power for dynamic portions of the music.
4 ohm Power
200 watts x 1 @ 12 volts
250 watts x 1 @ 14.4 volts

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INSTALLATION STEP 1
SETTING THE
HIGH POWER/HIGH CURRENT SWITCH
(applies to subwoofer channel only)
The Reference705’s subwoofer channel can be switched between “High Power” and “High Current” modes.
This allows the Reference705 to maximize power and efficiency at impedances ≥1 Ohm in “High Power”
mode, or down to 1/2 Ohm in “High Current” mode.
The circuit operates by selecting a set of power supply voltage rails best suited to your particular application.
One is a higher voltage “tap” optimized for high impedance applications while the other is lower voltage
designed to provide more current. Unlike other amplifiers, Soundstream’s REFERENCE amplifiers can be
configured to drive virtually any impedance and make maximum power!
To determine the setting for your application, follow the chart below:
4 Ω
12 Volts 2 ΩΩ 14.4 Volts 1 Ω 14.4 Volts 1/2 Ω 14.4 Volts
High Power
Watts 200
300 400 n/a
High Current
Watts 100 200 300 400
OTHER COMMENTS:
If you blow fuses with your Reference705, switch to the High Current mode. If
the problem persists, it is likely that the amplifier is seeing a dead short, either
in the speaker wire or in the speaker itself. Rectify the problem before
blowing multiple fuses!

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SELECTING THE CROSSOVER MODES
The Reference705 incorporates a sophisticated, fully adjustable electronic crossover for each of its
two pairs of channels and subwoofer channel. The Reference705 can drive a full system without
need of an outboard electronic crossover.
Before installing the amplifier, make certain the switches on the bottom are set to the correct
positions. After setting the switches, be sure to install the hole plugs included with the amplifier.
LOW PASS
The subwoofer channel is designed to operate in low pass or full range. The low pass is a continuously
variable 24 dB/octave electronic crossover with a range of 30 -120 Hz.
2-WAY
HIGH PASS
The high pass crossover is used for sending only midrange and high frequency information to particular
speakers. Activate the high pass crossover to drive satellite or coaxial speakers in the system along with
subwoofers. You can later adjust the exact frequency from the front of the amplifier. The high pass
frequency can be adjusted separately for either pair of channels of the amplifier.
REAR FILL DE-EMPHASIS
The Reference705 features an innovative rear fill de-emphasis circuit which places more emphasis on the
front stage when used in the five channel mode. The circuit removes frequencies above 7,000 Hz at the
rate of 6 dB/octave. By removing upper frequency information from the rear fill, a more natural sounding
rear fill effect is created.
3-WAY
MIDBASS/MIDRANGE BAND PASS
The Reference705 can be operated in midrange or midbass “band pass” configuration. In the 3-way
mode, you can tri-amplify with “active” midbass or midrange to maximize control over individual drivers.
The bandpass includes a low pass and a high pass filter, which work independent of one another, to drive
the midrange or midbass speakers. In 3-way crossover mode, channels 1 & 2 become HIGH PASS, and
channels 3 & 4 become BANDPASS. (NOTE: In 3-way mode, channels 3 & 4 inputs are not used.)
INSTALLATION STEP 2

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SELECTING INPUT MODES
The Reference705 can be driven with either one, two, or three pairs of stereo inputs. If your source unit has
front and rear outputs, you can take advantage of its fading capability by driving the Reference705 in 5
channel mode with two pairs of inputs. When operated in the 5 channel mode with 2 pairs of inputs, the
lowpass subwoofer channel will operate in a non-fading mode—it derives its signal from the front and rear
inputs. After setting the input mode switches, be sure to install the hole plugs included with the amplifier.
5 CHANNEL OPERATION WITH 4 CHANNELS OF INPUT
•Front input to Channels 1 & 2 and set stereo switch to either “Coherent Stereo” or “Mixed-Mono”
•Rear input to Channels 3 & 4 and set input switch to “3 & 4”; stereo switch to either “Coherent Stereo” or
“Mixed-Mono”
•Subwoofer input switch set to “CH 1 -4”
5 CHANNEL OPERATION WITH 2 CHANNELS OF INPUT
•Input to Channels 1 & 2; set stereo switch to either “Coherent Stereo” or “Mixed-Mono”
•Channels 3 & 4: set input switch to “Internal From Ch 1 & 2”; stereo switch to either “Coherent Stereo” or
“Mixed-Mono”
•Subwoofer input switch set to “CH 1 -4”
3 CHANNEL OPERATION WITH 2 CHANNELS OF INPUT
•Input to Channels 1 & 2: set stereo switch to “Mono”
•Input to Channels 3 & 4: set input switch to “3 & 4”; stereo switch to “Mono”
•Subwoofer input switch set to “CH 1 -4”
INSTALLATION STEP 3
For system
examples and
diagrams, see pages
14 -17.
COHERENT STEREO/BRIDGED MONO
The stereo channels of the Reference705 have the ability to operate in either of the following modes:
Coherent Stereo with identical left and right stereo channels for maximum fidelity.
Bridged Mono for dedicated single channel operation; ideal for using the Reference705 in three-channel
operation. It is also used when large amounts of power are necessary for single speakers. In bridged mono,
only the right channel input (per pair of channels) is active.
INSTALLATION STEP 4
In bridged mono, only the right channel
input is active.

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INSTALLATION STEP 5
WIRING DIAGRAM
WIRING
POWER AND GROUND
To assure maximum output from the Reference705, use high quality, low-loss power and ground
cables. The Reference705 will accept up to 4 gauge power and ground cables, which is the only
size recommended.
CIRCUIT BREAKERS/FUSES
EXTERNAL
Like all car audio amplifiers, the Reference705 must be protected with a fuse or circuit breaker
located within 18” of the battery. This will prevent a fire in the event of a shorted cable. The
value of the circuit breaker or fuse should be between 60 and 80 amps.
INTERNAL
The Reference705 is fused on its front panel with a 40 amp Maxi-fuse. In the event of a blown
power supply fuse, the “Fault” indicator on the front panel will light. Never replace the fuse with
a higher value than what is supplied. This may result in amplifier damage and will void the
warranty!
REMOTE TURN-ON
Connect the turn-on lead from the source unit to the “Remote” input on the amplifier. When +12
volts is received, the amplifier will turn on.
SIGNAL CABLE
Depending on your application, you may use one to three pairs of signal cables to drive your
Reference705. Use a high-quality cable that will be easy to install and has minimal signal loss to
guarantee optimum performance.
SPEAKER CABLE
The Reference705 will accept up to 8 gauge speaker cable. Use a high quality, flexible, multi-strand
cable for best performance and longevity. Soundstream Speaker120 (12 gauge) is ideal.