Velodyne FSX-12 User Manual

"If you know subwoofers, you know about Velodyne."

-Corey Greenberg

Home Theater Technology/February 1995
Face Off: Comparison of five subwoofers

"... the clean, full, and extended quality of the F-1800R's bass caused me
to gasp with the recognition that I was finally listening to a real subwoofer."

"... our entire listening room swelled with solid, satisfying bass, as if both
musician and instrument were in the room."

"...scenes such as the pre-battle sequence in Braveheart ... may very well
have threatened the room's structural integrity had we not backed off the
volume a bit..."

-Al Griffin

Home Theater/December 1996
Gear Guide
————————————————————————————————————

FSX-12

Owner's Manual

Printed on recycled paper.

8-97, #63-FSX12

Velodyne Acoustics, Inc.

1070 Commercial St. Suite #101

San Jose, CA 95112

408.436.7270 voice

408.436.7276 fax

Web Site: http://www.velodyne.com

E-mail: [e-mail]

SERVO-CONTROLLED

Audio/Video Subwoofer System

CAUTION

RISK OF ELECTRIC SHOCK

DO NOT OPEN

Caution

To reduce the risk of electric shock, do not remove cover (or back). No user-serviceable parts inside.
Refer servicing to qualified service personnel.

The lighting flash with arrowhead symbol is intended to alert the user to the presence of uninsulated
"dangerous voltage" within the product's enclosure that may be of sufficient magnitude to constitute a
risk of electric shock to persons.

The exclamation point symbol is intended to alert the user to the presence of important operating and
maintenance (servicing) instructions in the literature accompanying the subwoofer.

1. Read Instructions -- All safety and operating instructions should be read before the subwoofer is operated.

2. Retain Instructions -- The safety and operating instructions should be retained for future reference.

3. Heed Warnings -- All warnings on the subwoofer and in the operating instructions should be adhered to.

4. Follow Instructions -- All operating and use instructions should be followed.

5. Water and Moisture -- The subwoofer should not be used near water -- for example, near a bathtub, washbowl,
kitchen sink, laundry tub, in a wet basement, near a swimming pool or the like.

6. Carts and Stands -- The subwoofer should be used only with a cart or stand recommended by the manufacturer.

7. Wall or Ceiling Mounting -- The subwoofer should be mounted to a wall or ceiling only as recommended by
the manufacturer.

8. Ventilation -- The subwoofer should be situated so that its location or position does not interfere with its proper
ventilation. For example, the subwoofer should not be situated on a bed, sofa, rug, or similar surface that may
block the ventilation openings; or placed in a built-in installation such as a bookcase or cabinet that may impede
the flow of air through the ventilation openings.

9. Heat -- The subwoofer should be situated away from heat sources such as radiators, heat registers, stoves,
or other subwoofers that produce heat.

10. Power Sources -- The subwoofer should be connected to a power supply only of the type described in the
operating instructions or as marked on the subwoofer.

11. Power-Cord Protection -- Power-supply cords should be routed so that they are not likely to be walked on or
pinched by items placed upon or against them, paying particular attention to cords at plugs, convenience
receptacles, and the point at which they exit from the subwoofer.

12. "Caution: To prevent electrical shock, match wide blade of plug to wide slot, fully inserted." "Attention: Pour eviter
les chocs electriques, introduire lame la plus large de la fiche dans la borne correspondante de la prise et
pousser jusqu' au fond."

13. Cleaning -- The subwoofer should be cleaned only as recommended by the manufacturer.

14. Nonuse Periods -- The power cord of the subwoofer should be unplugged from the outlet when left unused for
a long period of time.

15. Object and Liquid Entry -- Care should be taken so that objects do not fall and liquids are not spilled onto the
enclosure.

16. Damage Requiring Service -- The subwoofer should be serviced by qualified service personnel when:
a. The power-supply cord or plug has been damaged.
b. Objects have fallen or liquid has been spilled into the subwoofer.
c. The subwoofer has been exposed to rain.
d. The subwoofer does not appear to operate normally or exhibits a marked change in performance.
e. The subwoofer has been dropped or damaged.

17. Servicing -- The user should not attempt to service the subwoofer beyond what is described in the operating
instructions.

All other servicing should be referred to qualified service personnel.

SPECIFICATIONS FSX-12

———————————————————————————————
Cabinet (h,w,d) 18" x 16.5" x 15"
Frequency Response 20Hz - 120Hz +/- 3 dB
Harmonic Distortion <1% (typical)
High Pass Crossover Passive 85Hz

(6 dB/octave slope)

Low Pass Crossover 40Hz - 120Hz (12 dB/octave initial,

48 dB/octave ultimate)
Phase O° / 180°
Amplifier (class AB) 120 W RMS

265W peak
Woofer 12" forward firing
Magnet 75 oz. (4.6 lbs.)
Magnet Structure 170oz. (10.5 lbs.)
Voice Coil 2.5" diameter
Inputs Line-level & speaker-level
Outputs Line-level & speaker-level
Warranty Two years (parts & labor)
Weight (approx.) 60 lbs. (27Kg)

Specifications are subject to change without notice.

FOR YOUR RECORDS. . .
DATE PURCHASED ________________________________________
DEALER __________________________________________________
SERIAL # _________________________________________________

*NOTE: Please complete and return your warranty card within ten (10) days.

1 14

☞

Troubleshooting & Service

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If you should experience a problem with the operation of your subwoofer, please check all
of the following before seeking service. Following is a simple troubleshooting guide to
assist you.

1. Verify unit is plugged in and power outlet used is active.

2. Is power switch on?

3. Is auto turn on/off set properly?

4. Is unit receiving an input signal from your source?

5. Have all controls on subwoofer (volume, crossover, phase, etc.) been properly set?

6. Is the mute on the remote control engaged?

7. Are both volume controls properly set?

8. If unit has been running at high levels for an extended period of time, one of the
protection circuits may be engaged.

•Has the built-in amplifier overheated?

•Is your power line voltage sagging under heavy use?

If the protection circuitry is active, the unit may cycle on and off until operating parameters
return to normal. Protection circuit operation is usually indicated by a blinking power led.
Under more serious conditions, the unit may shut off completely. Normal operation will
return upon cooling, but you may be required to turn the power off and then on again to
reset the unit.

The following conditions require service by a qualified technician:

1. The power cord has become damaged.

2. The unit does not appear to operate normally or exhibits a marked change in
performance.

3. The unit has been exposed to water.

4. Some part of the cabinet or circuitry is physically damaged.

Congratulations!

––––––––––––––––––––––––––––––––––––––––––––––—————––
Congratulations on your purchase of a Velodyne servo controlled subwoofer
system. This system represents the state of the art in accurate low frequency
reproduction. We believe these units to be some of the finest sounding subwoofers
available. When properly cared for, this exceptional subwoofer will provide you
with years of unparalleled listening pleasure. Enjoy!

Caution!

––––––––––––––––––––––––––––––––––––––––––––––—––————
Please observe the following instructions to insure safe and proper system
operation.

Warning!

To prevent fire or shock hazard, do not expose this equipment to rain or moisture.
To avoid electrical shock, do not open speaker enclosure or amp chassis cover.
Please observe all warnings on the equipment itself. There are no user serviceable
parts inside. Please refer all service questions to your authorized Velodyne dealer.

Prior to installation

Please unpack the system carefully! This unit is extremely heavy. Use caution when
lifting of moving to avoid injury. Remove all staples used to seal the carton as they
can scratch the cabinet. Please save the carton and all packaging materials for
future use. Packing this unit in any other carton may result in severe damage when
shipping. Please take a moment to record the serial number and date/location of
purchase in the space provided on the warranty card for future reference.

Note: Do not move unit while power is on. You may damage the Servo
Control circuitry!

Thank you for purchasing a Velodyne!

13

continued. . .

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2

Product Features & Controls

–––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––

• 12" subwoofer with 2 1/2" voice coil & 75oz. magnet

• Built-in 120 watt (RMS) class AB amplifier

• Accelerometer based servo control system for extreme accuracy

• Adjustable (40 to 120Hz) low-pass crossover (defeatable)

• 85Hz high-pass crossover outputs

• Line-level (RCA) inputs & outputs

• Speaker-level inputs & outputs

• Signal sensing auto turn on/off (defeatable)

• Variable volume control

• Selectable phase control (0˚ or 180˚)

• Frequency response of 20Hz - 120Hz +/- 3dB

• Multiple staggered low-pass crossovers; 12dB/octave initial,

48dB/octave ultimate

• Gain compression circuit prevents over excursion & amp clipping

• Power on & protection indicator LED (green)

Care of your subwoofer

–––––––––––––––––––––––––––––––––––––––––––––––––––—————–––
Do not use any harsh detergents or chemicals to clean the cabinet. Abrasives, detergents,
or cleaning solutions may damage the finish on the cabinet. We recommend using a damp
cloth to clean the cabinet.

During normal conditions, your new subwoofer may be left on continuously without any
problems. The unit is equipped with a signal-sensing turn on/off that will automatically turn
on the unit when a signal is present at the inputs and turn off the unit after several minutes
when there is no longer any signal at the inputs. If you plan to leave the subwoofer unused
for an extended period of time, we recommend that you turn off the master power switch
on the rear panel.

Installation

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Your new Velodyne servo subwoofer provides for a number of installation options. Read
all the installation information below in order to determine which installation option is best
for your system. Remember to perform all installation procedures with system

power turned off!!!

Inputs
Your new subwoofer is equipped with speaker-level and line-level inputs. Use the LINE
LEVEL jacks when connecting your subwoofer to a pre-amp, signal processor, line-level

crossover, or receiver with pre-amp level outputs. The SPEAKER LEVEL jacks connect
directly to the speaker outputs of any amplifier, integrated amplifier or receiver. Your
amplifier section will notice no additional loading effects when you use these inputs due
to their very high impedance.

3 12

☞ ☞

continued. . .

woofers actually add to the bass spectrum making it appear louder than recorded. This is
due to the additional and unwanted harmonics (distortion) of the fundamental signal.
While conventional subwoofers offer little to combat distortion products, we at Velodyne
have developed another way. . .

The Velodyne servo-control solution

–––––––––––––––––––––––––––––––––––––––––––––––––––—————–––
The Velodyne FSX-12 produces sound in the same manner as conventional loudspeakers:
a cone-shaped piston is forced to move by means of a linear motor composed of a coil
situated between the poles of a very strong permanent magnet. In our F-series products
however, a feedback mechanism is provided to link the driver to the amplifier creating a
control system loop.

At the heart of this control system is a low mass accelerometer rigidly attached to the voice
coil. The accelerometer continuously monitors cone motions, providing us with a feedback
signal for the servo control circuitry. This high-gain system is designed to improve linearity
and reduce distortion approximately 30 times over conventional non-servo systems. While
the input signal is being sent to the class AB amplifier which powers the driver, a continuous
signal representing cone motion is sent back to a comparator circuit. This circuit constantly
adjusts for any deviation between the input signal and the subwoofer's output. This self
regulation results in extreme control over cone movement, and very accurate low
distortion sound.

Important!!!
Do not use both LINE LEVEL and SPEAKER LEVEL connections simultaneously!

Volume control

This control allows you to balance the output from the subwoofer to the main speakers/
amplifier in your system. This control should be set to achieve similar output level from
both the main speakers and subwoofer when listening to music. The remote may then be
used for minute/temporary adjustments, such as increasing the volume for home theater
usage. A good starting point for the volume control is 3 or 4 dots from minimum.

Low-pass crossover- 40 to 120Hz

All inputs sum the left and right channels together, with the resulting signal passing
through an adjustable low-pass crossover before being amplified. The crossover control
allows you to adjust the upper limit of the subwoofer's frequency response from 40 to
120Hz. The subwoofer's response will begin rolling off above the frequency you set this
control to. You should set the crossover frequency to obtain a smooth and seamless
transition from the subwoofer to the main speakers in your system. If your main speakers
are smaller units with limited low frequency output, you may wish to choose a higher
frequency (such as 100-120Hz) than you would with larger speakers which have greater low
frequency output. With larger speakers, you might start with this control set lower, such
as 80Hz.

A bypass switch is also provided if you wish to use an external crossover. If you are not

using an external crossover, we recommend that you use the one provided
within the unit for optimum performance!

At typical listening levels, these servo controlled units produce less than 1% harmonic
distortion with input signals extending to 20Hz and below. Far better than conventional
designs currently on the market. This combination provides you with the best combination
of clean, deep, accurate bass, without making any sacrifice to distortion.

11 4

☞ ☞

Phase adjustment- 0˚/180˚

This control allows you the "reverse" the phase of the subwoofer's output signal 180˚ to
correct for any possible mismatch & resulting cancellation between the subwoofer and
your main speakers/amplifier. To adjust, simply listen to the system with music playing.
Then move the switch from one position to the other and listen for a change in low
frequency output. The correct position will have a greater amount of apparent low
frequency output.

continued. . .

Subwoofer Direct switch- In/Out

This switch allows the electronic crossover circuitry to be removed from the signal path.
This is required in certain installations which route the signal through external processors
with a crossover circuit of their own, such as the new digital units. Simply move the switch
to OUT to disengage the built in crossover. For all other installations which do not have
a separate electronic crossover we recommend you leave the internal crossover IN to
provide optimum performance.

Auto turn on switch- Auto/On

The auto turn on switch allows the user to utilize or bypass the automatic signal sensing
circuitry. When set in the AUTO mode with main power ON, the subwoofer will turn itself
on when an input signal is present. If no signal is present, after several minutes the unit will
shut itself off. When set in the ON mode, the auto turn on/off function is bypassed and the
unit will be on whenever the main power switch is on.

Power switch

The master power switch is located on the right half of the unit. This rocker style switch is
the main on/off for the unit. This switch should be set to position 1 (up) for on, and 0
(down) for off. If the unit is to be left unused for an extended period of time, the master
power switch should be turned off.

The first type of protection circuitry which prevents overdriving of the speaker or amplifier
operates constantly without being audible under most situations. In some extreme
situations (sustained high output levels), the unit may shut down momentarily. The green
power led may also blink rapidly. This indicates operation of the thermal protection
circuitry. If this should happen, you should reduce the volume setting or shut the unit off
until normal operating conditions return. You may also want to plug the unit into a different
wall outlet, as dropping power line voltage will be most noticeable under strenuous
conditions.

Distortion in loudspeakers

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Nonlinear distortion is a problem which plagues all speakers. This particular type of
distortion is a common problem in subwoofers, which must move large amounts of air to
produce adequate levels of deep bass. Nonlinear distortion is defined as any form of
distortion that moves energy from one portion of the audio frequency spectrum to
another. When a single tone is applied to a nonlinear system, the result is harmonic
distortion. In which some of the energy leaves the system at multiples of the original
frequency. When multiple tones are applied, intermodulation tones are produced, usually
as simple combinations of the input frequencies. Generally, 3% distortion is considered a
reasonable amount for speakers. This means that 3% of the total energy leaving the speaker
is at frequencies other than the intended input signal.

Line-level connection

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Figure 1 shows connection to a pre-amplifier's main outputs and returning them to your
amplifier inputs.

When installed in this fashion, your satellite speakers will be crossed over at 85Hz which
removes the lower bass from your amplifier and speakers, enabling them to do a better job
reproducing high frequencies. By utilizing this method, you will have a bi-amplified system,
gaining improved power and headroom for your system.

☞ ☞

Most subwoofers on the market today however, produce much more than 3% distortion
at common listening levels. Many models we have tested produce greater than 20%
distortion @ 20Hz when driven to 100dB. This is a typical output level obtained in many
systems, particularly home theater systems. Even at 1 watt, many conventional units
produce several percent distortion. Secondly, the odd order, higher harmonics are much
more offensive to the human ear than the closer 2nd harmonic.

An interesting result of this reduced distortion is that some of the bass, when played over
an extremely accurate subwoofer system, seems to actually be missing. The truth, however,
is that the "missing" bass was never there to begin with! Distortion products of conventional

continued. . .

105

locations when possible. When using a pair of Velodyne subwoofers in stereo, it is
preferable to place each subwoofer by the satellite of the same channel.

Caution!
This subwoofer has electronics built into the cabinet. Do not place the cabinet
next to sources of heat such as furnace registers, radiators, etc. Do not place
the unit near sources of excessive moisture, such as evaporative coolers,
humidifiers, etc. The power cord should be routed in such a way that it will not
be walked on, pinched, or compressed in any way that could result in
damaging the insulation or wire.

Regardless of where you install your Velodyne subwoofer, it must remain in an upright
position (woofer facing forward). Using, shipping, or otherwise storing the subwoofer in
any other position for an extended period of time may result in damage to the unit not
covered by warranty.

The FSX-12 subwoofer is not magnetically shielded. When installing near television
monitors, test placement with the monitor operational to observe any change in colors.
Certain types of televisions are particularly sensitive to stray magnetic fields. If your
television produces distorted colors after installing your subwoofer, simply increase the
distance between your television and the subwoofer, until normal color and operation is
returned.

Subwoofer outputs

The Velodyne subwoofer is designed to operate using the full range audio signal for input
when using the built-in crossover. Some processors/receivers, have a "subwoofer out" jack
that is internally filtered and designed to be used with a conventional amplifier and speaker.
In some rare cases, combining both an external crossover and the one internal to the
subwoofer may result in low output and increased noise. In these installations you may
need to bypass the internal crossover in either the processor or Velodyne subwoofer. In
some installations, simply setting one crossover to a higher frequency (such as 120 Hz) will
restore maximum performance.

To bypass the subwoofer's internal crossover when the unit is being fed a low pass signal
from another crossover, simply locate the switch marked X-over, OUT - IN on the rear panel
of the subwoofer and set to the OUT position. This will eliminate the internal crossover
from the signal path.

Figure 1: Installation using line-level inputs

VOLUME

LOW-PASS

CROSSOVER

POWER

CAUTION!CAUTION!CAUTION!CAUTION!

CAUTION!

Protection circuitry

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Your new subwoofer is equipped with special protection circuitry to provide maximum
performance with greatest reliability.

The unit is protected against:

1)Overdriving the speaker or amplifier.

2)Overheating the amplifier.

3)Excessive drop in power line voltage.

☞ ☞

FROM AMPLIFIER

RIGHT

PRE-AMP

MAIN OUTPUTS

RIGHT LEFT

LEFT

TO SPEAKERS

RIGHT LEFT

IN OUT

MADE IN USA

LEFT

~

RIGHT

MAIN INPUTS

RIGHT LEFT

Serial # Label

AMPLIFIER

MAIN OUTPUTS

RIGHT LEFT

TO SATELLITE SPEAKERS

continued. . .

69

Note. . . .

If not using an external crossover, you should use the built-in crossover for
optimal performance.

Figure 2: Installation using speaker-level (from amplifier) inputs

VOLUME

LOW-PASS

CROSSOVER

POWER

CAUTION!CAUTION!CAUTION!CAUTION!

CAUTION!

Speaker-level connection

––––––––––––––––––––––––––––––––––––––––––––––––––––—————––
Figure 2 shows an easy way to connect your Velodyne subwoofer directly to your receiver
or integrated amplifier.

When connected in this fashion, your satellite speakers will be crossed over at 85Hz, which
removes the lower bass from your speakers, enabling them to do a better job reproducing
high frequencies.

You may also connect your satellites directly to your receiver or amplifier along with the
subwoofer if you wish to bypass the internal high-pass crossover.

Caution!!!
To avoid damage to your main amplifier, be sure to maintain correct polarity
when making all connections. Red (positive) to red, and black (negative) to
black. Be sure that all connections are tight, and that there are no loose strands
or frayed wires.

Interconnect cables

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When installing your new Velodyne subwoofer using the line level connections, you should
always use shielded phono cables. There are many decent cables available today, most any
of which will work perfectly well. We do recommend that you keep the length of cable as
short as possible to avoid any potential noise problems.

FROM AMPLIFIER

LEFT

RIGHT

MAIN OUTPUTS
(speaker-level)

INTEGRATED AMP / RECEIVER

TO SPEAKERS

RIGHT LEFT

MADE IN USA

LEFT

~

RIGHT

IN OUT

SATELLITE SPEAKERS

Serial # Label

When using speaker level connections, use a decent quality speaker cable that mates well
with the connectors. Be very careful to avoid any loose strands or frayed wires which may
result in a short, which may damage your equipment. Cables of extremely large size are
typically not required. Extremely large gauge wire may not properly fit in the binding posts,
resulting in a poor connection and possible short circuits.

Placement

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True subwoofers operate at extremely low frequencies which are primarily omni-directional.
While it is recommended that the subwoofer be placed on the same plane as the satellite
speakers, room and system conditions often dictate otherwise. Keep in mind that frequency
response and output level can be drastically influenced by placement, depending on the
acoustic properties of the listening room. Typically, the optimum location for a subwoofer
is tucked away in a corner of your listening room. This location will usually offer the greatest
output levels and optimum low frequency extension. The worst location for a subwoofer
it typically far away from any walls, and close to the center of your room. Avoid these

continued. . .

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87