SONY SA-WM20 - Active Subwoofer Manual

Also See for SA-WM20:

User manual (2 pages)

Operating instructions (2 pages)

Service manual (10 pages)

Table of Contents

Contents

1 Precautions
2 Installation
3 Hooking Up the System
4 Listening to the Sound
5 Adjusting the Sound
6 Troubleshooting
7 Specifications
8 Documents / Resources
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SONY SA-WM20 - Active Subwoofer Manual

Precautions

To prevent fire or shock hazard, do not expose the unit to rain or moisture.
Do not install the appliance in a confined space, such as a bookcase or built-in cabinet.

On safety

Before operating the woofer, be sure that the operating voltage of your woofer is identical with that of your local power supply.
Unplug the woofer from the wall outlet if it is not to be used for an extended period of time. To disconnect the cord, pull the cord by grasping the plug. Never pull the cord itself.
Should any liquid or solid object fall into the woofer, unplug the woofer and have the woofer checked by qualified personnel before operating it any further.
AC power cord must be changed only at the qualified service shop.

When turning on or off an am plifier or other equipm ent
Lower the volume of the amplifier to minimum.

To avoid dam ag ing the woofer

Be careful in setting the volume control of the amplifier to avoid an excessive input power.
Do not attempt to open the enclosure or remold speaker units and networks.

In case color irreg ularity is observed on the nearby TV screen
With the magnetically shielded type of the speaker system, the speakers can be installed near a TV set. However, color irregularity may still be observed on the TV screen depending on the type of your TV set.

If color irreg ularity is observed...

Turn off the TV set once, then turn it on after 15 to 30 minutes.

If color irreg ularity is observed ag ain...

Place the speakers further apart from the TV set.

When how ling occurs
Relocate the speaker or turn down the volume of the amplifier.

On installation

Do not install the woofer near heat sources such as radiators or air ducts, or in a place subject to direct sunlight, excessive dust, mechanical vibration or shock.
Good ventilation is essential to prevent internal heat build-up in the woofer. Place the woofer in a location with adequate air circulation. Do not place the woofer on a soft surface.
Use caution when placing the speaker on a specially treated (waxed, oiled, polished, etc.) floor, as staining or discoloration may result.

On cleaning the cabinet
Clean the cabinet with a soft cloth lightly moistened with water. Do not use any type of abrasive pad, scouring powder or solvent such as alcohol or benzine.
If you have any questions or problems concerning your woofer that is not covered in this manual, please consult your nearest Sony dealer.

Installation

Since the human ear cannot detect the direction and position where the bass sound being reproduced by a woofer (below 200 Hz) comes from, you can install the woofer wherever you like in your room. To obtain a better bass reproduction, we recommend you to install the woofer on a solid floor where the resonance is unlikely to occur.

Notes

Always install the woofer vertically, keeping a few centimeters from away the wall.
Do not place an object on the woofer or sit on it.
If the woofer is installed in the center of a room, the bass could be extremely weakened. This is due to the influence of the standing wave of the room. If this happened, move the woofer away from the center of a room or eliminate the cause of the standing wave, by installing a bookshelf on the wall, etc.

Hooking Up the System

Overview
Use the LINE IN jacks or the SPEAKER IN terminals of the woofer when you connect the amplifier.

If your amplifier has one of the following types of output jacks, connect the LINE IN jack and the amplifier's jack using the supplied audio connecting cord.
- MONO OUT jack
- MIX OUT jack
- SUBWOOFER output jack(s)
- SUPER WOOFER output jack(s)
If your amplifier does not have the above mentioned output jacks, connect the speaker terminals of the amplifier to the SPEAKER IN terminals instead. ()

Before you get started

Turn off the power of the amplifier and the woofer before making any connection.
Use the audio connecting cords that are supplied to the respective equipment. If there are not enough audio connecting cords to make the necessary connections, you need to purchase some optional audio connecting cords.
Be sure to make connections firmly to avoid noise.
Connect the AC power cord from the woofer to a wall outlet.
You cannot connect the CENTER output jack for use with Dolby Pro Logic function to the woofer. Bass sound is not output with some Dolby Pro Logic modes.

Connecting to an amplifier with a single set of speaker terminals ()
Connecting with a single set of speaker terminals
If your amplifier is equipped with a single set of speaker terminals, connect the woofer to the amplifier, and then connect the front speakers to the woofer.

Hookups

Connect the woofer to the amplifier.
Connect the SPEAKER IN terminals of the woofer to the amplifier's speaker terminals with the speaker cords. Be sure to connect both L and R channels.
Connect the front speakers to the woofer.
Connect the speakers to the speaker terminals of the woofer.

Connecting to an amplifier with double (A +B) sets of speaker terminals ()
Connecting with double (A +B) sets of speaker terminals
If your amplifier has double (A+B) sets of speaker terminals, connect both the woofer and the front speakers to the amplifier.

Hookups

Connect the front speakers to the amplifier.
Connect the speakers to your amplifier's speaker terminals (A).
Connect the woofer to the amplifier.
Connect the SPEAKER IN terminals of the woofer to the amplifier's speaker terminals (B) using speaker cords (supplied).

When using the double (A+B) sets of speakers, make sure that you select the "A+B" position with your amplifier.

Note
When you are using speaker terminal (A) only (front speaker only) or when the power of the amplifier is turned off, turn down the volume or turn off the power of the woofer otherwise, hum noise may be heard.

Connecting to an amplifier with a special jack for a subwoofer
If your amplifier has a special jack for a subwoofer (like a MONO OUT jack, MIX OUT jack, SUBWOOFER jack or SUPER WOOFER jack), connect the LINE IN jack of the woofer to one of those jacks.

Hookups ()
Hookups
Connect the MONO OUT jack of your amplifier to the LINE IN jack of the woofer with the supplied audio connecting cord.

Note
If the output level of your amplifier is not large enough, the sound may not be loud enough. In this case, connect the speaker terminals of the amplifier directly to the SPEAKER IN terminals of the woofer.

Connecting the AC power cord

Connect the AC power cord from the woofer and from your amplifier to a wall outlet.
Make sure that power to the woofer is turned off before you plug in or unplug any power cord.

Listening to the Sound

Turn on the amplifier and select the program source.
Press POWER ().
The woofer turns on and the POWER indicator lights up in green.
Play the program source.
Adjust the VOLUME so that sound from the front speakers is not distorted.
If it is distorted, the sound from the woofer will also be distorted.

Notes

Never set the amplifier's tone control (BASS, TREBLE, etc.) or the equalizer output to a high level or input sinewaves of 20 Hz to 50 Hz recorded on a commercially-available test disc or special sound (bass sound of electronic musical instrument, pop noise of analog disc turntable, sound with abnormally enhanced bass, etc.) in a high level to this unit. These actions may cause damage to the speakers. When a special disc containing abnormally enhanced bass is played, noise may be output in addition to the original sound. In such a case, decrease the sound level.
The subwoofer output signal (DOLBY digital (AC-3) signal) of the digital surround processor sold singularly is set 10 dB higher by Dolby laboratories Licensing Corporation. In the case of using normally, adjust the subwoofer level.

Adjusting the Sound

You can adjust the sound of the woofer to suit the sound of your front speakers. Reinforcing the bass sound gives you a greater sense of atmosphere.

Adjust the cut-off frequency.
Turn the CUT OFF FREQ control, depending on the reproduction frequencies of your front speakers.
Refer to the following when adjusting.
1. Typical very small sized speakers: 5 – 7 cm dia.
2. Typical small sized speakers: 8 –15 cm dia.
3. Typical medium sized speakers: 16 –24 cm dia.
4. Typical large sized speakers: more than 25 cm dia.
  To make the most of the low level converter function of Dolby digital, turn the CUT OFF FREQ as high as possible when playing back the Dolby digital (AC-3).
Adjust the volume level of the woofer.
Turn the LEVEL control so that you can hear the bass sound a little more than before. To increase the volume, turn the control clockwise. To decrease the volume, turn the control counterclockwise.
Play your favorite song and movie.
Male vocal tunes and voice containing bass sounds are most suitable for adjustment. Turn the volume for front speakers to the same level as usual.
Select the phase polarity.
Use the PHASE selector to select the phase polarity.
Repeat steps 1 to 4 to adjust for your preference.
Once you have adjusted the woofer to the settings you desire, use the VOLUME control on the amplifier to adjust the volume of the woofer with that of the other speakers. You don't need to adjust the woofer settings when you change the volume level of the amplifier.

Notes

If the sound distorts when you turn on the bass reinforcement from your amplifier (such as, DBFB, GROOVE, the graphic equalizer, etc.), turn off the bass reinforcement and adjust the sound.
Do not turn the volume of the woofer to maximum. Doing so may weaken the bass sound. Moreover, extraneous noise may be heard.
Selecting NORMAL or REVERSE with the PHASE selector reverses the polarity and may provide better bass reproduction in certain listening environments (depending on the type of front speakers, the position of the woofer and the adjustment of the cut-off frequency). It may also change the expanse and tightness of sound, and effect the feeling of the sound field. Select the setting that provides the sound you prefer when listening in your normal listening position.

Setting the speaker ()

To prevent speaker vibration or movement while listening, attach the supplied foot pads to the speaker.

Troubleshooting

If you experience any of the following difficulties while using the woofer, use this troubleshooting guide to help you remedy the problem. Should any problem persist, consult your nearest Sony dealer.

There's no sound

Check that this woofer and components are connected correctly and securely.
Turn LEVEL clockwise to turn the volume up.
Select SPEAKER or LINE with IN PUT selector.
Reset the level.

The sound has suddenly stopped

The speaker cords may have short-circuited. Connect the cords properly.

The sound is distorted

The input signal is imperfect.
The input signal level is too high.
Set the CUT OFF FREQ as high as possible when playing back the Dolby digital (AC-3).

Severe hum or noise is heard

Connect the ground wire of the turntable properly.
The contacts between the plugs of the connecting cords and the corresponding jacks have not been made properly. Connect the plugs firmly.
The audio system is picking up some noise from a TV set. Move the audio system away from the TV set or turn the TV set off.

Specifications

System
Type Active Subwoofer (magnetically shielded design)
Speaker unit Woofer: 20 cm dia, cone type
Amplifier section Continuous RMS output: 50 W (0.8%)
Reproduction frequency range 28 Hz – 200 Hz
High frequency cut-off frequency 50 Hz – 200 Hz
Phase selector NORMAL, REVERSE

Inputs
Input jacks LINE IN: input pin jack
SPEAKER IN: input terminals
Output jacks SPEAKER OUT: output terminals

General
Power requirements Mexican model: 120 V AC, 60 Hz
Asian model: 230 V AC, 50/ 60 Hz
Other model: 120 V AC, 50/ 60
Hz, 220-230 V AC, 50/ 60 Hz
Power consumption 50 W
Dimensions Approx. 270 x 325 x 385 mm (w/ h/ d)
Mass 10 kg

Supplied accessories
Foot pads (4)
Audio connecting cord (1 phono plug – 1 phono plug), 2 m (1)
Speaker cords, 2.5 m (2)

Design and specifications are subject to change without notice.

Setting the voltag e selector (voltag e selector equipped m odels only) ()

Check that the voltage selector on the rear panel of the player is set to the local power line voltage. If not, set the selector to the correct position using a screwdriver before connecting the AC power cord to a wall outlet.