BassBoss VS21-MK3 User manual

Single 21”
Powered Subwoofer
VS21-MK3
User Manual

VS21-MK3 User Manual bassboss.com
3
2
Table of Contents
Overview 2
Design 3
QuickStartGuide 4
OperationandControls 4
OutboardProcessorWarning 5
SetupProcedure 5
PowerDistribution 6
IndicatorLEDs 6
OnboardPresets 7
HowtoUsethePresets 7
CardioidMode 8
Troubleshooting 9
Specifications 10
Warranty 11
SafetyInformation 12
FCCComplianceNotice 13
on anything over 110V. The amplifier’s high peak-output voltage provides for intense high SPL
hits while its sustained output is unparalleled in its ability to deliver the liquid lows. The amplifier
is passively cooled via its external heat-sink and by woofer-generated air-flow through the port.
When necessary, two blower-fans will engage to provide additional forced-air cooling capacity in more
extreme conditions.
New to the MK3 are Neutrik powerCON True 1 TOP (Total Outdoor Protection) waterproof mains
connectors. Waterproof mains connectors along with a totally isolated input connection section and
cones that are waterproofed make the MK3 series the powered loudspeakers that can be used outdoors
without fear of what the weather will bring. (Or used indoors without fear of what the partiers bring.)
Electrical power is converted into the much more desirable acoustical power by a robust, neodymium
motor, 21-inch woofer with a massive 4.5-inch (115mm) voice coil. Neodymium magnets are lighter, and
their higher intensity provides higher eiciency, so the result is a lighter and louder cabinet than those
with ferrite drivers.
The MK3 features an all-new DSP. The comprehensive suite of processing includes high-pass and low-
pass filters as well as multiple protection systems and limiters to prevent driver overload in as many
ways as possible, including thermal, excursion and clipping. The five levels of protection actively prevent
overheating of the voice coil, minimize long-term thermal compression and limit excursion. Because
they operate in 5 dierent modes, the limiters are sophisticated enough to have virtually no eect on the
transient response and peak output of the loudspeaker.
The new DSP features an Ethernet interface. This can be used to control the cabinets from a computer
to load software or firmware updates and in the future to send signal via Milan AVB as updates become
available.
When connected to a computer cabinets can be grouped to respond to commands together so the
levels of multiple subwoofers can be controlled together and separately from the levels of tops cabinets.
In addition to individual and grouped level controls, presets can be loaded and signal levels and
temperatures can be monitored. Each cabinet includes a two-port switch so multiple cabinets can be
chained on the same data cable.
The MK3 DSP features 8 presets. All of the presets are compatible with all the presets in the MK3 Top
Boxes and are also compatible with previous generation tops.
The 7th preset is intended for use with vinyl records or any time infrasonic feedback is possible. It can
also be used to keep operators out of trouble with the neighbors and the local authorities. The 8th preset
is the Cardioid mode setting. More information on Cardioid mode usage can be found on page 8.
The cabinets are constructed from 18mm Baltic Birch plywood. Each cabinet features dado and rabbet
joinery throughout, so all seams are extremely strong and long-lasting. Stainless steel bolts are used
to secure the drivers, amplifier and pole sockets so that the fasteners will never rust or seize up.
The cabinet is finished in an extremely rugged, black polyurea coating and the driver is protected by a
black powder-coated, perforated steel grille.
The VS21-MK3 Single 21” Powered Subwoofer oers low-frequency extension similar to vented
dual 18” subwoofers in combination with the hard hitting punch of horn loaded subwoofers.
The VS21-MK3 brings the world of extended low frequency together with the world of high-impact:
You’re no longer forced to choose either deep OR punchy, as the VS21 oers both.
The VS21-MK3 is a vented, short horn hybrid sixth order bandpass which features a massive
displacement, long excursion 21” woofer, rear-loaded into a large acoustical volume that is tuned to
a low frequency, and front-loaded onto a short horn. The vented enclosure section provides extended
low frequency performance and the horn section provides increased upper frequency sensitivity and
improved transient response.
The VS21-MK3 features a 2500W amplifier with an auto-sensing, globally compatible power supply
that can run on mains supplies anywhere between 90 and 250 Volts. Full output power is available
VS21-MK3 Single 21”
Powered Sub

VS21-MK3 User Manual bassboss.com
5
4
Quick Start Guide
1. Ensure the cabinet is secure and stable, on level ground.
2. Attach any poles/additional mid-high cabinets to the subwoofer.
3. Connect signal via the XLR-F input.
4. Connect the XLR-M connector to additional subs or tops.
5. Connect the mains power and verify the “Ready” LED is lit.
BASSBOSS systems are easy to set up quickly. The best possible results are achieved consistently
because of the integrated nature of the designs. All BASSBOSS loudspeakers are complete, inte-
grated systems, featuring the cabinet, transducer, amplifier and a comprehensive suite of process-
ing. Setup is particularly easy because the products integrate with each other.
Provided the cabinets are physically aligned, any BASSBOSS sub can be combined with any BASS-
BOSS top and their outputs will be phase-coherent. This means no cancellations and no gaps in the
response at the crossover frequency, regardless of which preset is selected.
The designs are also performance-optimized for maximum SPL with maximum reliability.
Operation & Controls
There are 2 controls on the amplifier.
1: Input
This knob adjusts the input level from -72dB to -0dB. To avoid distortion and clipping, make sure the
input signal doesn’t exceed +22dB and the output doesn’t reach clipping before you achieve the desired
sound level.
While the amplifier has built-in limiters and safety features to protect itself and the speaker, it can’t
protect the speaker from distorted incoming signals. The amplifier will simply amplify the clipped signal,
which can do the same damage as clipping an amplifier. Since it’s essentially impossible for these
amplifiers to clip, signal-level clipping is the most common cause of damage to these speakers.
If you hear distortion, lower the input level right away.
2: Preset Select
Pressing the Preset Select button cycles through presets 1-8, and pressing it again after preset 8
returns to preset 1. Each preset includes specific low-pass and high-pass filter frequencies and the
necessary alignments to maintain phase coherence in the crossover range when used with BASSBOSS
top speakers.
Presets help you fine-tune the balance between the subwoofers and top speakers. More details on the
dierent combinations are on page 7.
Outboard Processing Warning
Third-party outboard processing (Drive Racks, etc.) are not recommended and are not necessary
with BASSBOSS MK3 series powered loudspeakers. Outboard processing will not improve, and will
very likely degrade the sound quality, reliability and output capacity.
Using external processing may cause driver damage.
Setup Procedure
The cabinet should be placed so that it is secure and stable, on level ground. The extremely high output
levels may cause the cabinet to move if the floor isn’t level or is very slick. Although it has rubber feet, it may
be necessary to put anti-slip mats under the cabinet on certain surfaces to prevent unwanted movement.
All subwoofer cabinets are equipped with 35mm steel pole sockets to allow mid-high/tops cabinets
to be held above them. Due to the high-output nature of these subwoofers, it’s recommended to use
a locking type of pole, such as with an expanding mandrel, so that the pole cannot vibrate when the
cabinet is producing high levels.
Signal cables should be connected via the XLR-F input. It’s recommended to run balanced signal cables
to minimize the chance of noise and ground-loop hum. The incoming signal should be unprocessed
because all the necessary processing is done in the built-in DSP. The signal should be run directly from
the outputs of a mixer or controller.
The XLR-M connector provides a full-range, unprocessed, pass-through connection to additional
cabinets. This output can be connected to additional subs or tops. Up to 12 cabinets can be connected
on a single output from a mixer or controller.
After connecting the XLR-M, connect the mains power. The power connector is a Neutrik powerCON
TOP waterproof type. The power connector inserts with the silver tab rotated counter-clockwise from
vertical at about the 10:00 position. Once inserted rotate it clockwise to the 12:00 position to lock in
place. Once locked, this connector is waterproof.
This connector also serves as the power switch. To disconnect and remove the connector pull back
on the silver tab to unlock it and rotate it counter-clockwise. Once rotated to the insertion angle the
connector can be removed. There is no secondary switch. The unit is on when the power is connected.
When connecting and disconnecting, no force should need to be applied. If the connector doesn’t insert
and rotate smoothly, either it’s in the wrong position or is damaged and should be replaced.
Always use a grounded outlet. The supplied power cord includes a standard grounding NEMA 5-15
(Edison) 120-Volt US wall plug. In unfamiliar locations it’s recommended to verify the correct wiring of
outlets before powering your system.

VS21-MK3 User Manual bassboss.com
7
6
Power Distribution
Connect no more than one 5000W or two 2500W subwoofer amplifiers to a single 20A circuit. If you need
to share circuits don’t exceed two BASSBOSS single-driver subwoofers or one double-driver subwoofer
along with one or two top speakers on the same circuit.
Avoid powering all subwoofers on the same circuit. Instead, use separate circuits for each subwoofer and
top speaker combo to help prevent overloading a single circuit and tripping a breaker.
The amplifiers can operate on mains supply from 100 to 250VAC. To connect to voltages other than
120V, a country-specific mains connector plug must be used. Contact your dealer for information about
purchasing cables for alternate voltages.
You can use pass-through power connections to power extra cabinets. Optional True 1 TOP cables let
you link power between subwoofers and top speakers. Don’t plug in devices that use over 15A on a single
power outlet. Contact your dealer for information about purchasing linking power cables.
It’s highly recommended to connect all signal and power cords to the speakers before plugging the
power cords into mains outlets. When your speaker is powered on, you’ll see all the indicator lights turn
on and then show the system’s current status.
Indicator LEDs
Indicator LEDs – Left side, bottom to top:
Ready: Indicates that power is on and the system is ready to play.
Signal: Indicates the presence of input signal.
-12dB: Indicates there is 12dB of headroom remaining before reaching maximum output.
-6dB: Indicates there is 6dB of headroom remaining before reaching maximum output.
Limiting: Indicates one of the channels is reducing the incoming signal level to prevent overdrive.
Overheat: Indicates the amplifier is reducing output to prevent shut-down from overheating.
Protect: Indicates the amplifier is shut down due to a condition that could cause further damage.
The Protect LED also is engaged when the system has been muted via the software.
Comm Link: Indicates communication is active on the LAN connection(s).
Onboard Presets
Indicator LEDs - Right side: Presets from bottom to top:
High-pass and low-pass filter frequencies with included phase compensation.
Preset 1 - 27 Hz - 70 Hz
Preset 2 - 27 Hz - 75 Hz
Preset 3 - 27 Hz - 80 Hz
Preset 4 - 27 Hz - 85 Hz
Preset 5 - 27 Hz - 90 Hz
Preset 6 - 27 Hz - 95 Hz
Preset 7 - 40 Hz - 100 Hz (Vinyl/Good Neighbor Mode)•
Preset 8 - Cardioid Mode (Use only when cabinet is facing away from audience)
*Use preset 7 when playing vinyl records, dealing with noise complaints from deep bass, or when there
is risk of infrasonic feedback.
Instructions on linking to your computer for remote monitoring and control:
www.bassboss.com/software
Additional presets will be available for download at the above link as they are developed.
To be notified when new presets are released register your gear at: www.bassboss.com/support
How to Use the Presets
Setting the low-pass filter frequency on the subwoofer to match the top cabinet’s high-pass filter frequency
and balancing their levels will achieve the smoothest sound across the frequency range.
There are no incompatible combinations.
Selecting high numbered presets on subs with low-numbered presets on tops will result in increased system output in
the overlap range, which can be helpful in some situations but can also result in a “boomy” sound.
When the subwoofer levels are to be run higher than tops levels, (which is almost always) the eective crossover moves
higher in frequency. If you intend to run your system “bass-heavy” it’s recommended to run lower-numbered presets on
the subs and higher-numbered presets on the tops to avoid an excessively “boomy” sound.
Selecting low-numbered presets on subs with high-numbered presets on tops can result in a lack of “punch” in certain
combinations. This is most likely when not enough level is available from the subwoofer(s).
When not enough output is available from the sub(s), using a preset combination with overlap can help provide a little more
bass level but it does limit the maximum level of the tops due to the added demand for low-frequencies from the tops.
It’s recommended that you try several, if not all, combinations when first setting up to determine which combination
works best in each environment. You will likely choose dierent combinations for wood floors, concrete floors and
outdoors. Experiment with dierent combinations to dial in your preferred combination in dierent environments.

VS21-MK3 User Manual bassboss.com
9
8
Cardioid Mode
Preset 8: Cardioid Mode
Toachievecardioidoperation,youneedatleastonesubwooferfacingtheaudienceandonecabinetin
cardioidmodeplacedfacingawayfromtheaudience.Ideally,youshouldhavetwocabinetsfacingthe
audience and one facing away from the audience. The cabinets facing the audience should have the
samepresetloadedinthem.ThecabinetfacingawayfromtheaudienceshouldbesettotheCardioid
preset-Preset8.TheCardioidModecabinetshouldbeplacedbetweentheaudience-facingcabinetsfor
cancellationdirectlybehindthearray.
Themainsubwoofer cabinetsface theaudience anduseoneofthefirst 7presets,whilethecardioid
cabinetfacesawayfromtheaudiencewithPreset8selected.Whentwocabinetsarefacingforwardand
oneisfacingbackwardincardioidmode,settheinputlevelsthesameforallcabinets,withthesamesignal
goingtoall.Whenonecabinetisfacingforwardandoneisfacingbackwardincardioidmode,setthecardioid
cabinet’slevel6dBlowerthantheforward-facingcabinet,withbothcabinetsreceivingthesamesignal.
Ifthere’sonlyonecabinetfacingforwardandanotheronefacingbackwardincardioidmode,youcan
placethecardioidcabinetontopoftheforward-facingcabinet.Ifyouplacethecardioidcabinetnext
totheforward-facingcabinet,positiontheforward-facingcabinetsfurtherawayfromthestageorthe
areawhereyouwanttoreducesoundlevels.Themostsignificantsoundreductionhappensalongan
imaginarylinedrawnfromthecenteroftheforward-facingcabinet’swooferbackthroughthecenterof
thecardioidcabinet’swoofer.
How and When to Use Cardioid Mode
Cardioidmodedoesn’tmakethesoundlouderfortheaudience.Instead,itreducesthebasslevelbehind
thesubwooferstacks.Whenyouhavetwosubwoofersfacingtheaudienceandaddathirdoneincardioid
mode,thesoundlevelinfrontofthetwosubwooferswon’tchangemuch.However,thesoundlevelbehind
themwilldecrease.
Insomesituationsawallorstructuremayreflectthesoundradiatingfromtherearofthesubwoofersback
towardstheaudience.Thatreflectedsoundcancausephasecancellationsleadingtoalossofimpactand
unevenfrequencyresponse.Cardioidmodecanhelpeliminatethosecancellationsbeforetheyhappen,
leadingtobettersoundqualityandimpactfortheaudience.
Troubleshooting
If, after following the previous instructions for setup, you have no output from the loudspeaker:
Verify that the green Ready LED is lit. If NOT lit, check the following:
1. Is the power cord plugged into a live outlet?
2. Is the Neutrik powerCON connector rotated into the locked position?
If the green Ready LED is lit, check the following:
1. Is the red Protect LED illuminated? The unit may be in protect mode or set into mute via software.
2. Is the signal cable connected to the input?
3. Is the signal cable connected to an operating output at the other end?
4. Is there signal flowing to the input? Check the integrity of the cable against a dierent cable.
5. Is the volume knob turned all the way down or at a very low level?
6. Is the signal flowing to the input full-range?
Filters in the signal may remove the operating frequencies of the loudspeaker receiving them.
7. If you’re connected via LAN, check the level and filter settings in the software.
Important Notes
Shielded data cables must be used.
To minimize the occurrence of noise and interference, always use shielded signal cables. Avoid routing
signal or data cables close to equipment that produces high-intensity electromagnetic fields such as
transformers, power cables and loudspeaker wires.
Do not coil excess power cable. Do not coil or wrap power cables and signal or data cables together.
Area of
Reduced
Bass Level
Audience
Area

VS21-MK3 User Manual bassboss.com
11
10
Warranty
WARRANTY INFORMATION | Our fully-transferable warranty covers all BASSBOSS products.
STANDARD CABINET WARRANTY
BASSBOSS loudspeaker cabinet integrity, including all joinery, fasteners, handles and wood, is
warranted against defects in materials and workmanship for a period of six (6) years from the date of
purchase. This warranty does not cover items that are intended to wear and can be replaced if worn
or damaged. Examples of items not covered by this warranty are cabinet feet, grilles and the finish or
coating applied to the cabinet.
ENHANCED COMPONENT WARRANTY
BASSBOSS amplifiers and electronic components are covered against failures due to defects in
materials and/or workmanship for a period of three (3) years from the date of purchase.
TRANSDUCER WARRANTY
Transducers are covered against failures due to defects in materials and/or workmanship for two (2)
years from the date of purchase.
OUR SUPPORT
Warranty support is a service, and part of that service includes helping you prevent failures and
minimize repair and shipping costs.
Please do not ship products without obtaining a return authorization number (RMA) by contacting
BASSBOSS at bassboss.com/support. If you need to ship your speaker for service, BASSBOSS
technicians will provide assistance on shipping and packaging requirements specific to your
service needs.
WARRANTY LIMITATIONS
During the warranty period, if your loudspeaker malfunctions or fails due to any defect in components
or manufacturing, the failed parts will be repaired or replaced. This warranty does not extend to damage
resulting from improper installation, misuse, neglect or abuse. Warranty coverage and eligibility will be
determined upon inspection by BASSBOSS personnel. This warranty does not cover labor other than
that authorized and performed by BASSBOSS personnel. Service will be performed upon the return of
the failed unit, together with its original sales receipt or other proof of purchase, to BASSBOSS or an
Authorized Service Facility. Purchaser is responsible for all costs of shipping and handling. Cosmetic
damage is specifically excluded from this warranty. This warranty is rendered void if service, repairs
and/or modifications are attempted or made by anyone not specifically authorized by BASSBOSS to
perform said services. Please contact BASSBOSS or your local BASSBOSS dealer before attempting
any repairs and before shipping parts in for service. This warranty gives you specific legal rights, and
you may also have other rights, which vary from state to state.
Specifications
Acoustical
Description: Subwoofer, single 21” powered and processed
Frequency Response (±3 dB): 27 - 100 Hz (Preset dependent)
Maximum Measured Output: 135 dB SPL, 1 meter, half-space (ground plane)
Max SPL (Peak)*: 138 dB
Nominal Dispersion (Hº x Vº): 360 x 360 - Cardioid mode available with multiple boxes
Electrical
Amplification: 2500 Watt RMS Class D Amplifier
Processing: Integrated comprehensive DSP provides high pass, low pass, phase alignment
and limiting
Electrical Connectors, Amp: Neutrik powerCON True 1 TOP waterproof connectors
Electrical Connector, Mains: Standard US 3-pin grounding 120V electrical plug: NEMA 5-15
Voltage Operating Range: 100-240V
Current Draw, Nominal: 4.6A @ 120 volts
Current Draw, Peak: 20A
Signal Input Connector: XLR-F
Signal Output Connector: XLR-M (Direct pass-through, unprocessed)
Physical
Enclosure Type: Vented, short horn hybrid
Transducer: 1 X 21” diameter (540 mm) neodymium motor woofer. 58 mm (2.28”) peak to peak
excursion with waterproof fiber composite cone
Cabinet Construction: CNC machined 18 mm Baltic Birch plywood with dado and Rabbet joinery
Dimensions (HxWxD): 36” x 24” x 36” (91.44 cm x 60.96 cm x 91.44 cm) - 37.5” (95.25 cm) high with feet
Net Weight: 180 lbs. (82 kg)
Shipping Weight: 230 lbs. (104 kg)
Exterior Finish: Weatherproof bonded high-pressure polyurethane
Grille: Perforated, powder-coated steel
Pole Sockets: 3 (35 mm) pole sockets
Handles: 6 Integrated handles
Feet: 12 interlocking rubber feet
Suspension System: 16 X M10 threaded flypoints
Optional
Transport Dollies (H or V): Dolly cart with 4 locking casters and recesses to accept interlocking cabinet feet
Cover: Heavy-duty padded nylon transport covers for 1 cabinet
Online Information: bassboss.com/VS21
Our proactive philosophy causes specifications to be subject to change whenever improvements are made.
*Peak output is calculated using “industry standard” techniques. These calculation methods create theoretical
specifications that are inflated over what can actually be achieved. BASSBOSS real world output specifications
are provided as “Maximum Sustained Output” ratings, which reflect actual measured, continuous output levels.

VS21-MK3 User Manual bassboss.com
13
12
Manufacturer
True Lee Loudspeakers | BASSBOSS 2028 E Ben White Blvd. #240-8220 Austin TX 78741
We declare, under our sole responsibility, that to the best of our knowledge to which this
declaration relates, our products are in conformity with the applicable requirements.
Product: VS21-MK3 Subwoofer Intended use: Professional Audio Loudspeaker
Safety Information
Important information regarding safety and the use of your loudspeakers:
To prevent potentially dangerous exposure to high levels of acoustic pressure, never stand in the
immediate vicinity of loudspeakers driven at a high level without hearing protection. Professional
loudspeaker systems are capable of causing a sound pressure levels detrimental to human health.
When a transducer capable of producing high sound levels is being used, it is necessary to wear
ear plugs or protective earphones to prevent hearing damage.
Even seemingly non-critical sound levels (from approximately 95 dB SPL) can cause hearing
damage if people are exposed to it over a long period. Anyone exposed to these levels should use
appropriate hearing protection devices. System and venue owners and operators are encouraged
to make hearing protection devices available to all customers and sta members.
In order to prevent accidents when setting up the loudspeakers or loudspeaker stands, make sure
they are standing on a firm surface. Ensure that all additional hardware, fixings and fasteners used for
installation or mobile deployment are of an appropriate size and load safety factor.
Pay attention to the manufacturers’ instructions and to the relevant safety guidelines. Regularly check
the loudspeaker housings and accessories for visible signs of wear and tear, and replace them when
necessary. Regularly check all load bearing bolts in the mounting devices.
Caution: Loudspeakers produce a static magnetic field even if they are not connected or are not
in use. Therefore make sure when erecting and transporting loudspeakers that they are nowhere
near equipment and objects which may be impaired or damaged by an external magnetic field.
A distance of 3 feet (1m) should be maintained between loudspeakers and sensitive equipment such as
CRT monitors or magnetic storage media.
Never attempt to carry out any operations, modifications or repairs that are not expressly described in
this manual. Contact your dealer or BASSBOSS support if the product is not functioning properly.
For installation purposes BASSBOSS strongly recommends that this product be installed by a qualified,
professional installer who can ensure correct installation and certify that it is installed in compliance
with the regulations in force.
The audio system must comply with current local standards and regulations regarding electrical systems.
FCC Compliance Notice
Note: This equipment has been tested and found to comply with the limits for a Class A digital device,
pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against
harmful interference when the equipment is operated in a commercial environment.
This equipment generates, uses and can radiate radio frequency energy and, if not installed and used
in accordance with the instruction manual, may cause harmful interference to radio communications.
Operation of this equipment in a residential area is likely to cause harmful interference in which case the
user will be required to correct the interference at their own expense.
WARNING
This is a class A product. In a domestic environment, this product may cause radio
interferences, in which case the user may be required to take corrective measures.
Este manual está disponible en español en nuestro sitio web en bassboss.com/support

Single 21”
Subwoofer
VS21-MK3
bassboss.com/support
Need more assistance?
We’re here to help.