Soundstream Technologies 705s User Manual

REFERENCE

705s

5/3 Channel

Power Amplifier

OWNERS MANUAL AND

INSTALLATION GUIDE

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CONGRATULATIONS!

You now own the REFERENCE705s 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 Reference705s sounds better than

anything you’ve ever heard, exercise caution to prevent hearing damage.

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TABLE OF CONTENTS

Features ..............................................................................................................4 - 5

REFERENCE705s Diagram ................................................................................6 - 7

REFERENCE Power Supply Design ........................................................................ 8

Setting High Power/High Current ............................................................................. 9

Selecting Crossover Modes .................................................................................... 10

Selecting Input Modes ............................................................................................ 11

Setting Coherent Stereo/Bridged Mono .................................................................. 12

Wiring (with Diagram) ......................................................................................12 - 13

Installation and Mounting ....................................................................................... 14

Level Setting ........................................................................................................... 15

Crossover Adjustments ........................................................................................... 16

AIRBASS™ ............................................................................................................ 16

LSE.Q Subwoofer Equalization Circuitry ................................................................ 17

Sample Systems ..............................................................................................18 - 21

Protection Circuitry & Troubleshooting ................................................................... 22

Service .................................................................................................................... 23

Specifications ......................................................................................................... 23

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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).

• Chassisink

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 listening experience (in 5 channel mode only).

TM

Darlington Power Array - Soundstream’s “overbuilding” of the output section

• 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 Reference705s 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 Reference705s' subwoofer channel is designed to

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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 Delay

TM

Muted Turn-on/off Circuit - A unique circuit which completely eliminates

amplifier-related turn-on/off noises.

• Flexible Input Sensitivity accepts voltages from 200 mV (80 mV on the subwoofer channel)

to 5.0 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.

• AIRBASS™ Upgradable - This feature allows RF wireless remote control level adjustment of

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Reference705s

6

Key to Callouts

1. Fault LED - Indicates a blown fuse.

2. High Power LED - Indicates amplifier power on in "High Power" mode.

3. High Current LED - Indicates amplifier power on in "High Current" mode.

4. Main Fuse - Main power supply fuse.

5. +12V - Connected to a fuse or circuit breaker, then to the battery's positive post.

6. GND - Main ground connection. Bolt to a clean chassis ground in the vehicle.

7. REM - Remote turn-on input from the head unit. Accepts +12V.

8. Speaker Output Connections - Mono subwoofer channel.

9. LSE.Q - Frequency and Q adjustments.

10. Low Pass Crossover Adjustment Pot - Subwoofer channel; crossover frequency setting for the internal low
pass filter.

11. Input Level - Subwoofer channel level control.

12. Inputs - Right and left channel RCA inputs for the subwoofer channel.

13. Speaker Output Connections - Channels 1 & 2.

14. Crossover Adjustment Pots - Channels 1 & 2 crossover frequency setting for the internal high pass filter in

2-way mode, and channels 1 & 2 and 3 & 4 crossover frequency setting for the internal band pass filter in 3­way mode.

15. Input Level - Channels 1 & 2 level control.

16. Inputs - Right and left channel RCA inputs for channels 1 & 2.

17. Speaker Output Connections - Channel 3 & 4.

18. High Pass Crossover Adjustment Pot - Channels 3 & 4 crossover frequency setting for the internal high
pass filter in 2-way mode.

19. Input Level - Channels 3 & 4 level control.

20. Inputs - Right and left channel RCA inputs for channels 3 & 4.

21. Subwoofer Channel Crossover Switch - Select LOW PASS for use with the internal crossover, or BYPASS
for use with an external crossover.

22. Subwoofer Channel Input Select - Selectable inputs from internal (from channels 1 - 4) or external (from
Subwoofer local RCA inputs).

23. Coherent Stereo™/Bridge Mono Switch - Channels 1 & 2; Select "Bridge" for bridged mono operation (use
right channel input). Select "Stereo" for coherent stereo operation.

24. Channels 1 & 2 and 3 & 4 Bandpass Range Crossover Switch - 3-way operation only; Select "MID" for
use with midrange drivers and tweeters, or "MIDBASS" for use with midbass drivers and satellites.

25. 2-way / 3-way Crossover Switch - Channels 1 & 2; Select 2-way for high pass / low pass operation, or 3-
way for highpass / bandpass / lowpass operation.

26. Channels 1 & 2 Crossover Switch - Select "HIGH PASS" for use with the internal crossover, or "FULL
RANGE" for use with an external crossover.

27. Coherent Stereo™/Bridge Mono Switch - Channels 3 & 4; Select "Bridge" for bridged mono operation (use
right channel input). Select "Stereo" for coherent stereo operation.

28. 2-way / 3-way Crossover Switch - Channels 3 & 4; Select 2-way for high pass / low pass operation, or 3-
way for highpass / bandpass / lowpass operation.

29. Channels 3 & 4 Crossover Switch - Select "HIGH PASS" for use with the internal crossover, or "FULL
RANGE" for use with an external crossover in 2-way mode.

30. Channels 3 & 4 Input Select - Selectable inputs from internal (from channels 1 & 2) or external (from
channel 3 & 4 local RCA inputs) in 2-way mode.

31. Rear Fill De-emphasis Switch - Channels 3 & 4; Select "ON" to engage the 6 dB/octave low pass filter at 7
kHz for use in 5-channel / 2-way mode.

32. High Power / High Current Switch - Subwoofer channel only.

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14.4 volts

REFERENCE POWER SUPPLY DESIGN

The Reference705s employs an extremely efficient unregulated pulse-width modulated
power supply. Like the rest of the REFERENCE amplifiers from Soundstream, the
Reference705s 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 Reference705s can

4 Ohm Sub Channel Watts

12 volts

0 50 100 150 200 250

4 ohm Power

200 watts x 1 @ 12 volts

Read this, or sparks will fly!

The Soundstream REFERENCE705s amplifier has extensive internal power supply capacitance, called the Ultra­Low ESR Capacitance Bank. Multiple small input power capacitors act as an internal "stiffening capacitor".

Because of the large amount of internal capacitance, there may be a sizable spark when connecting the power
and ground lead to the amplifier for the first time. In order to charge the capacitor bank without a spark, we
suggest you do the following:

1. Connect the +12 volt cable to the amplifier and to the battery.

2. Connect one end of the ground cable to the chassis of the vehicle.

3. We have supplied a 150 ohm, 2 watt resistor with the amplifier. One leg of the resistor has been connected
to the ground terminal of the amplifier.

4. To charge the capacitor bank, touch the loose end of the ground cable to the open leg of the resistor for at
least 45 seconds.

5. Remove the resistor, and connect the ground wire.

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