Audio T Verdict
The Dynaudio Sub 3 is a compact active subwoofer that adds genuine low-frequency depth and authority without demanding a large amount of floor space.
Its 24cm MSP+ Hybrid Drive woofer and 300W amplifier deliver controlled bass down to 22Hz, making it suitable for music systems, television sound and multichannel home cinema.
Adjustable crossover, phase, level and satellite high-pass settings make it considerably more flexible than a basic subwoofer. Careful positioning and setup are still essential, but the controls provide the tools needed to integrate it properly.
For customers who want deeper bass from compact standmount speakers or greater impact from a home cinema system, the Sub 3 is a discreet and capable solution.
Dynaudio Sub 3 Active Subwoofer
The Dynaudio Sub 3 is a compact sealed active subwoofer designed to add controlled low-frequency extension to stereo music and home cinema systems.
Its main components and features include:
- One front-firing 24cm MSP+ Hybrid Drive woofer
- A powerful 300W amplifier
- A sealed cabinet
- Low-frequency extension down to 22Hz
- Adjustable low-pass crossover
- Adjustable output level
- Selectable phase
- Automatic signal-sensing power control
- Stereo line-level connections
- A dedicated LFE connection
- Satellite outputs with selectable high-pass filtering
- Compact cabinet dimensions
The Sub 3 is equally suitable for adding bass extension to a compact stereo system or reproducing the dedicated low-frequency effects channel within a home cinema installation.
Compact Subwoofer, Serious Bass
The Sub 3 measures approximately 266mm wide, 276mm high and 320mm deep, allowing it to fit into rooms where a larger subwoofer would be visually or physically intrusive.
Despite its relatively compact cabinet, Dynaudio specifies bass extension down to 22Hz.
This makes the Sub 3 suitable for reproducing low-frequency information from:
- Kick drums
- Bass guitars
- Electronic music
- Grand piano
- Pipe organ
- Orchestral recordings
- Film soundtracks
- Television and gaming
The objective is not simply to make a system sound louder or heavier. Correctly adjusted, the Sub 3 should extend the main speakers while remaining difficult to identify as a separate source of sound.
24cm MSP+ Hybrid Drive Woofer
Low frequencies are reproduced by a front-firing 24cm Dynaudio MSP+ Hybrid Drive woofer.
The large diaphragm provides the cone area and excursion required to move substantial volumes of air while remaining compact enough for the Sub 3 cabinet.
The driver is designed to provide:
- Deep low-frequency extension
- Controlled cone movement
- Strong transient response
- Useful output from a compact enclosure
- Consistent performance with music and film soundtracks
The woofer, amplifier and cabinet are developed as a complete system rather than treated as unrelated components.
MSP+ Hybrid Drive Technology
The MSP+ Hybrid Drive diaphragm applies Dynaudio’s experience with Magnesium Silicate Polymer to a driver developed specifically for low-frequency reproduction.
The diaphragm must combine:
- Suitable stiffness
- Controlled internal damping
- Low-frequency excursion
- Resistance to unwanted flexing
- A stable connection to the motor assembly
The driver is optimised for subwoofer duties rather than being adapted from a conventional midrange or bass unit.
Front-Firing Driver
The woofer is mounted on the front of the cabinet rather than facing the floor.
A front-firing arrangement can make the driver easier to position and inspect while reducing dependence on the precise clearance beneath the enclosure.
The protective front grille should remain clear of:
- Furniture
- Curtains
- Boxes or equipment
- Heavy fabric
- Objects that could vibrate against the cabinet
300W Built-In Amplifier
The Sub 3 contains a dedicated 300W amplifier matched to the electrical and mechanical requirements of its 24cm woofer.
Integrating the amplifier within the cabinet allows Dynaudio to optimise:
- Driver control
- Low-frequency extension
- Maximum output
- Protection
- Crossover behaviour
- Standby operation
No separate power amplifier is required, although the Sub 3 must be connected to a suitable mains socket.
Sealed Cabinet Design
The Sub 3 uses a sealed cabinet rather than a bass-reflex port.
A sealed enclosure provides several practical and acoustic advantages:
- No bass port to obstruct
- No audible port turbulence
- A smooth low-frequency roll-off
- Good transient behaviour
- Relatively flexible room placement
- A compact overall cabinet
Room boundaries will still affect bass output, so the Sub 3 should not automatically be pushed into the nearest corner without listening and adjustment.
22Hz to 175Hz Frequency Range
Dynaudio specifies a frequency range extending from approximately 22Hz to 175Hz.
The final audible result will also depend on:
- Subwoofer position
- Room dimensions
- Listening-seat position
- Low-pass crossover setting
- Phase setting
- Output level
- The bass extension of the main speakers
- Room-correction or AV calibration
Very low frequencies are strongly influenced by the room, so published extension should not be considered independently of placement and setup.
Adjustable Low-Pass Crossover
The low-pass control determines the highest frequencies reproduced by the Sub 3.
A lower setting may suit larger floorstanding speakers that already produce substantial bass, while a higher setting may be appropriate for compact standmount or satellite speakers.
The correct setting should provide a smooth transition without producing:
- A gap between the speakers and subwoofer
- Excessive upper bass
- Male voices appearing to come from the subwoofer
- A thick or slow tonal balance
- An obvious separate source of bass
Begin with a setting appropriate to the main speakers’ useful bass extension, then adjust by listening.
Crossover Settings for Different Speakers
There is no single crossover frequency that suits every system.
As a broad starting point:
- Small satellite speakers may require a higher crossover
- Compact standmount speakers may suit a middle setting
- Larger standmount speakers may require a lower crossover
- Floorstanding speakers may need only the lowest bass reinforced
- An AV receiver may manage the crossover itself
The final setting depends on the loudspeakers, room, listening position and whether bass management is being performed elsewhere in the system.
Adjustable Output Level
The level control adjusts the relative volume of the Sub 3 compared with the main speakers.
Too little output can leave the system sounding lightweight, while excessive output can make bass notes sound slow, dominant or disconnected.
For music, begin with a conservative level and increase it gradually until the system gains depth and scale without making the subwoofer obvious.
A Subwoofer Should Not Constantly Draw Attention to Itself
A useful setup test is to switch the Sub 3 off after listening for several minutes.
The system should lose depth, scale and low-frequency atmosphere, but switching the subwoofer back on should not make every recording sound artificially bass heavy.
Selectable Phase
The phase control changes the timing relationship between the Sub 3 and the main speakers.
The correct setting is normally the one that produces the strongest and most even transition around the crossover frequency from the main listening position.
An unsuitable phase setting can cause partial cancellation, resulting in:
- Weak bass around the crossover region
- An uneven transition between the speakers and subwoofer
- Reduced impact
- Inconsistent bass between different seats
Test the available phase settings using familiar music or measurement equipment while seated at the normal listening position.
Automatic Signal-Sensing Power
The Sub 3 can detect an incoming audio signal and switch into operation automatically.
After a period without a suitable signal, it can return to standby.
This allows the subwoofer to remain ready for use without requiring the rear power control to be operated before every listening session.
Very low source levels may occasionally delay automatic activation, in which case the source output and subwoofer level structure should be checked.
Stereo Line-Level Inputs
Stereo RCA line-level connections allow the Sub 3 to be integrated with compatible stereo amplifiers, pre-amplifiers, streamers and active speaker systems.
A stereo connection may be useful where:
- The amplifier provides left and right pre-amplifier outputs
- The source provides a variable line-level output
- The subwoofer is being placed between a pre-amplifier and power amplifier
- The system uses active loudspeakers with a suitable subwoofer feed
The source output must provide variable volume control unless the Sub 3 is connected through another component that tracks the system volume.
Dedicated LFE Connection
A dedicated LFE connection allows the Sub 3 to reproduce the low-frequency effects channel from a compatible AV receiver or surround processor.
When an AV receiver manages the crossover, speaker size and distance settings, the Sub 3’s own low-pass control may need to be set according to the manufacturer’s recommended bypass or maximum position.
The AV receiver should then manage:
- Crossover frequency
- Subwoofer level
- Distance or delay
- Room correction
- Bass routing
- The dedicated LFE channel
Satellite Outputs
The Sub 3 provides line-level outputs for compatible satellite speakers or downstream amplification.
These connections can form part of a stereo system in which the signal passes through the subwoofer before reaching the main speakers’ amplifier or active electronics.
Compatibility depends on the complete system layout and the available inputs and outputs on the partnering equipment.
Selectable Satellite High-Pass Filtering
The satellite outputs provide selectable high-pass filtering to reduce the deepest bass sent to compatible main speakers.
Removing very low frequencies from smaller speakers can provide:
- Reduced driver excursion
- Greater playback headroom
- Lower distortion
- Improved midrange clarity
- A more controlled transition to the subwoofer
A flat setting can be used where the main speakers should continue to operate across their complete natural range.
Integrating the Sub 3 with Passive Speakers
A conventional passive loudspeaker cannot connect directly to the Sub 3’s line-level sockets.
The system requires suitable amplification and a compatible line-level subwoofer feed from one of the following:
- An integrated amplifier with pre-amplifier or subwoofer output
- A separate pre-amplifier
- A streaming amplifier with subwoofer output
- An AV receiver
- An external crossover or bass-management system
Speaker-level connection is not a substitute unless a compatible external converter is specifically suitable for the system.
Integrating the Sub 3 with Active Speakers
The Sub 3 can be used with compatible active loudspeakers that provide a variable subwoofer output or allow line-level bass management.
Current Dynaudio Focus models provide dedicated subwoofer management through the Dynaudio app, including presets for selected Dynaudio subwoofers.
Explore:
Using the Focus Subwoofer Preset
Current Dynaudio Focus firmware includes setup presets for selected Dynaudio subwoofers, including the Sub 3.
The Focus system can then manage suitable starting values for integration before further adjustment is made for:
- Subwoofer distance
- Speaker distance
- Output level
- Phase
- Time alignment
- Room behaviour
The exact controls available depend on the Focus firmware and app version installed.
Stereo Music Systems
Within a stereo system, the Sub 3 can extend compact speakers without changing their basic tonal character.
Potential benefits include:
- Deeper bass extension
- Greater scale
- Improved reproduction of low-frequency ambience
- More convincing drums and bass instruments
- Additional headroom when satellite high-pass filtering is used
- More flexible bass positioning than relying on the main speakers alone
The crossover and level should be set carefully so the system still sounds balanced on recordings containing little deep bass.
Home Cinema Systems
The Sub 3 can reproduce the dedicated low-frequency effects channel within a compatible home cinema system.
This can add weight and impact to:
- Explosions
- Vehicle effects
- Musical scores
- Atmospheric low-frequency sound
- Games
- Television drama and live events
Browse home cinema amplifiers and AV receivers at Audio T for compatible bass-management options.
Using One or Two Subwoofers
One Sub 3 can provide substantial bass extension in many small and medium-sized rooms.
Two subwoofers can sometimes improve bass consistency across a wider listening area by exciting the room from different positions.
Potential advantages of a two-subwoofer system include:
- More even bass between seats
- Reduced dependence on one room position
- Greater available output
- Lower workload for each individual driver
- More flexible placement
Two subwoofers do not automatically guarantee better results. Both units must be positioned, level matched and time aligned correctly.
Subwoofer Positioning
Low frequencies interact strongly with walls, floors and room dimensions.
Placing the Sub 3 close to a wall will normally increase perceived bass output. Positioning it in a corner can increase output further, but may also exaggerate particular frequencies.
Alternative positions may provide:
- More even bass
- Better definition
- Reduced boom
- Improved integration with the main speakers
- More consistent output across different seats
Do not assume that the visually neatest position will provide the most accurate result.
The Subwoofer Crawl
A practical way to explore possible positions is to place the Sub 3 temporarily near the main listening seat and play a repeating bass passage or low-frequency test signal.
Move around the room and listen for positions where the bass sounds relatively even and controlled rather than exaggerated or weak.
Promising locations can then be tested with the subwoofer moved into those positions.
Move the Subwoofer Safely
Switch the Sub 3 off and disconnect its mains and signal cables before moving it.
Lift the cabinet rather than dragging it across the floor, and protect high-gloss surfaces from jewellery, buckles and hard objects.
Listening-Seat Position
The position of the listener can affect bass just as much as the position of the subwoofer.
A seat placed directly against a wall may experience excessive bass at some frequencies, while another position can produce a significant bass reduction.
Moving the listening seat by a relatively small distance can sometimes improve low-frequency consistency without changing any equipment settings.
Room Correction
A compatible AV receiver, streaming system or external processor may provide automatic room correction.
Room correction can help manage:
- Subwoofer level
- Distance and delay
- Crossover behaviour
- Strong room resonances
- Integration with the main speakers
Electronic correction should be used after sensible physical positioning rather than as a substitute for it.
Sub 3 or Sub 6?
Choose the Sub 3 When
- A compact cabinet is essential
- A 24cm woofer suits the room
- 300W amplification provides the required output
- Straightforward analogue controls are preferred
- The room is small or medium in size
- The lower purchase price better suits the system
Choose the Sub 6 When
- Greater output and headroom are required
- Dual opposing woofers are preferred
- DSP setup and parametric equalisation are useful
- Speaker-specific performance maps are required
- Balanced connections are important
- The larger cabinet can be accommodated
The Dynaudio Sub 6 is a larger and more advanced model with dual opposing drivers, DSP control and speaker-specific performance maps.
Finish Options
Audio T currently lists the Sub 3 in understated finishes designed to complement Dynaudio loudspeakers and modern living spaces.
Finish availability may include:
Availability can vary according to current UK production and stock.
Cabinet Care
Clean the cabinet with a soft, dry or very slightly damp cloth.
Do not use:
- Abrasive cleaning products
- Furniture polish
- Solvents
- Aerosol sprays
- Excessive water
Keep liquids away from the rear controls, signal connections and mains inlet.
Ventilation and Heat
Although the Sub 3 uses an efficient amplifier, its rear electronics require suitable ventilation.
Do not install the subwoofer:
- Inside a sealed cabinet
- Directly against a radiator
- Beside another strong heat source
- Where curtains cover the rear electronics
- Where liquids could reach the mains connection
Allow air to circulate around the cabinet and rear amplifier panel.
Power and Signal Cables
The Sub 3 requires a mains connection and an appropriate line-level audio cable.
Cable choice depends on the system:
- A single RCA subwoofer cable for an AV receiver or mono subwoofer output
- A stereo RCA interconnect for left and right line-level operation
- Additional RCA cables where the satellite outputs are used
Keep signal cables away from mains adapters and tightly bundled power cables where practical.
Key Features
- Compact active subwoofer
- Suitable for stereo and home cinema systems
- Front-firing 24cm woofer
- Dynaudio MSP+ Hybrid Drive technology
- Built-in 300W amplifier
- Sealed cabinet design
- Low-frequency extension down to 22Hz
- Upper operating range up to approximately 175Hz
- Adjustable low-pass crossover
- Adjustable output level
- Selectable phase
- Automatic signal-sensing power mode
- Manual power mode
- Stereo RCA line-level inputs
- Dedicated LFE connection
- Stereo satellite outputs
- Selectable satellite high-pass filtering
- Suitable for compact standmount speakers
- Suitable for floorstanding speakers
- Suitable for compatible active speakers
- Compatible with current Dynaudio Focus systems
- Suitable for AV receiver bass management
- Approximately 266mm wide
- Approximately 276mm high
- Approximately 320mm deep
- Approximately 10.5kg weight
- Black Satin finish
- White Satin finish
- Up to three-year electronic and eight-year passive-part warranty after registration
Frequently Asked Questions
Is the Dynaudio Sub 3 an active subwoofer?
Yes. It contains a dedicated 300W amplifier and requires a mains connection.
Which driver does it use?
A front-firing 24cm Dynaudio MSP+ Hybrid Drive woofer.
Is the cabinet ported?
No. The Sub 3 uses a sealed enclosure.
What is the lowest published frequency?
Dynaudio specifies low-frequency extension down to approximately 22Hz.
How powerful is the amplifier?
The built-in amplifier is rated at 300W.
Can it be used with a stereo amplifier?
Yes, provided the amplifier or another system component offers a suitable variable pre-amplifier or subwoofer output.
Can it connect directly to passive speakers?
No. Passive speakers require their own amplifier. The Sub 3 uses line-level audio connections.
Can it be used with active speakers?
Yes, where the active speaker system provides a compatible variable subwoofer or line-level output.
Is it compatible with Dynaudio Focus speakers?
Yes. Current Focus systems include setup options for selected Dynaudio subwoofers, including the Sub 3.
Can it be used with an AV receiver?
Yes. A compatible AV receiver can connect through the dedicated LFE input and manage crossover, level, distance and room correction.
What does the low-pass control do?
It determines the highest frequencies reproduced by the subwoofer.
What does the phase control do?
It changes the timing relationship between the Sub 3 and the main speakers around the crossover region.
Does it switch on automatically?
Yes. An automatic mode can detect an incoming signal and place the subwoofer into operation.
Does it provide high-pass filtering for the main speakers?
Yes. The line-level satellite outputs provide selectable high-pass filtering for compatible systems.
Does the Sub 3 require speaker cable?
No. It uses line-level RCA connections rather than conventional passive speaker cable.
Which cable is needed for an AV receiver?
A suitable RCA subwoofer cable is normally used between the AV receiver’s subwoofer output and the Sub 3’s LFE input.
Where should it be positioned?
Begin near the front speakers, then test alternative wall and room positions while listening for even, controlled bass.
Can it be placed in a corner?
Yes, but a corner will normally increase bass output and may exaggerate particular room frequencies.
Can two Sub 3 subwoofers be used?
Yes, provided the system offers suitable signal distribution and both subwoofers are correctly positioned, level matched and time aligned.
Does it require a grille?
The front driver is protected by the supplied cabinet grille.
What are the dimensions?
Approximately 266 x 276 x 320mm (W x H x D).
How much does it weigh?
Approximately 10.5kg.
Which finishes are available?
Audio T currently lists Black Satin and White Satin, subject to availability.
What warranty is available?
Registration within 12 months may extend total cover to 36 months for electronic parts and 96 months for eligible passive parts, subject to Dynaudio’s full warranty terms and proof of purchase.
Related Dynaudio Products and Audio T Guides
Why Buy From Audio T?
- Dynaudio Sub 3 demonstrations
- Comparisons with the Dynaudio Sub 6
- Stereo and home cinema system-matching advice
- Compatibility checks for amplifiers and active speakers
- AV receiver and LFE setup guidance
- Low-pass crossover adjustment
- Output-level and phase setup
- Satellite high-pass configuration
- Subwoofer positioning advice
- Room-mode and listening-position assessment
- Single and dual-subwoofer setup guidance
- Dynaudio Focus app and subwoofer-preset assistance
- Subwoofer cable selection
- Finish selection and cabinet-care advice
- Home setup may be available by arrangement
- Part exchange may be available on suitable existing equipment
- Dynaudio warranty-registration guidance
- Ongoing system, setup and after-sales support
Contact your local Audio T store to arrange a demonstration or discuss positioning, crossover, phase, cabling and system matching for the Dynaudio Sub 3.