Audio T Verdict
The Sennheiser AMBEO Sub is not simply there to make an AMBEO system louder. Its job is to extend the system properly into the lowest frequencies, using an 8-inch long-throw driver, sealed enclosure and substantial 350W Class D amplifier to reach a claimed 27Hz.
It is also unusually flexible within the AMBEO family. Pair it wirelessly with the AMBEO Soundbar Plus or Mini and the whole system can be calibrated together, with support for as many as four wireless AMBEO Subs if the room demands it. Owners of the larger AMBEO Soundbar Max can use the same Sub, but through a conventional wired RCA connection.
For most rooms, one AMBEO Sub will be more than enough. But if you want greater low-frequency extension, more physical impact from films and a better chance of achieving even bass across a larger seating area, it is the natural next step for an AMBEO system.
Sennheiser AMBEO Sub
The Sennheiser AMBEO Sub is a compact active subwoofer developed to extend the low-frequency performance of Sennheiser's AMBEO home cinema systems.
Inside its sealed enclosure is a single 8-inch long-throw cellulose-cone woofer powered by a dedicated 350W RMS Class D amplifier. Sennheiser specifies a frequency response extending from 27Hz to 80Hz at -3dB, providing considerably deeper bass than the AMBEO soundbars can reproduce on their own.
The AMBEO Soundbar Plus and Mini can connect to the Sub wirelessly using Bluetooth Low Energy and the LC3 codec, while a conventional mono RCA input also allows wired operation with compatible equipment.
- Dedicated Sennheiser AMBEO active subwoofer
- Sealed enclosure
- 8-inch long-throw cellulose-cone woofer
- 350W RMS Class D amplification
- 27Hz to 80Hz frequency response
- Wireless connection with AMBEO Soundbar Plus
- Wireless connection with AMBEO Soundbar Mini
- Up to four wireless AMBEO Subs supported
- Bluetooth Low Energy 5.2 wireless connection
- LC3 wireless audio codec
- Up to 10m wireless range
- Mono RCA wired input
- Compatible with AMBEO Soundbar Max by wired RCA
- Room calibration as part of compatible AMBEO Soundbar systems
- Sennheiser Smart Control integration with compatible AMBEO systems
- Compact approximately 27.7cm-wide enclosure
- Approximately 8.2kg weight
8-Inch Long-Throw Woofer
The AMBEO Sub uses a single 200mm / 8-inch long-throw cellulose-cone driver.
A long-throw design allows the cone to move through a greater distance than a conventional short-excursion driver, helping it move the volume of air required to reproduce genuinely low frequencies from a relatively compact cabinet.
This is particularly important with film soundtracks, where low-frequency effects often extend substantially below the range of ordinary television speakers or compact soundbars.
350W RMS Class D Amplifier
The woofer is powered by its own 350W RMS Class D amplifier.
Because the amplification is built directly into the Sub, the connected soundbar does not have to supply any of the power required to drive it.
The internal amplifier and driver can therefore be designed as a complete system rather than asking the customer to match a separate power amplifier to the subwoofer.
Bass Down to 27Hz
Sennheiser specifies the AMBEO Sub's frequency response from 27Hz to 80Hz at -3dB.
That takes the system well into the region where bass is increasingly felt as physical pressure as well as heard.
Deep soundtrack information can include:
- Explosions
- Thunder
- Vehicle and aircraft effects
- Film-score percussion
- Electronic bass
- Low organ notes
- Low-frequency atmosphere and room effects
Why 27Hz Matters
The lowest frequencies in a film soundtrack are often responsible for the sense of scale and physical impact that separates a convincing home cinema system from simply making the television louder.
A subwoofer capable of reaching into the upper 20Hz region can reproduce information that smaller loudspeakers and soundbars may roll away considerably earlier.
The result should not simply be more bass, but a deeper foundation underneath the complete soundtrack.
Sealed Enclosure
The AMBEO Sub uses a closed, or sealed, cabinet rather than a reflex port.
A sealed design avoids port noise and gives Sennheiser direct control over the relationship between the amplifier, driver and enclosed air volume.
It also allows the cabinet to remain relatively compact for an 8-inch subwoofer capable of reaching a specified 27Hz.
Wireless With AMBEO Soundbar Plus
The AMBEO Soundbar Plus can connect to the AMBEO Sub without requiring an audio cable between the two products.
The wireless connection uses Bluetooth Low Energy 5.2 together with the LC3 codec and has a specified range of up to approximately 10 metres.
You still need a mains power connection for the Sub itself, but the absence of a signal cable gives considerably more freedom when choosing its position in the room.
Wireless With AMBEO Soundbar Mini
The smaller AMBEO Soundbar Mini also supports wireless AMBEO Sub connection.
This is particularly useful because the Mini is designed around a very compact enclosure. Adding the Sub allows low-frequency duties to be handled by a dedicated 8-inch driver while the soundbar concentrates on the rest of the soundtrack.
Up to Four Wireless AMBEO Subs
The AMBEO Soundbar Plus and Mini support as many as four AMBEO Subs connected wirelessly.
That does not mean every installation needs four subwoofers.
For most ordinary living rooms, a single AMBEO Sub is likely to provide more than enough low-frequency output.
Why Use More Than One Subwoofer?
Adding multiple subwoofers is not purely about maximum bass output.
Low frequencies interact strongly with room dimensions and boundaries, creating areas where particular bass notes become exaggerated and other areas where they partially cancel.
Using several carefully positioned subwoofers can help create a more even low-frequency response across a wider listening area.
One Sub or Several?
Start with one. In many rooms that will be all you need. Multiple AMBEO Subs become particularly useful in larger rooms, installations with several important seating positions or spaces where room modes make it difficult to achieve consistent bass from a single location.
Wireless Multi-Sub Calibration
When AMBEO Subs are wirelessly connected to an AMBEO Soundbar Plus or Mini, the soundbar and connected subwoofers are calibrated together as a complete system.
The Smart Control app guides the user through connection and room calibration, allowing the soundbar to account for the presence of the connected Sub or Subs when calculating the final system response.
The Soundbar Performs the Room Measurement
The AMBEO Sub should not be confused with a standalone subwoofer containing its own independent room-measurement microphone.
With the AMBEO Soundbar Plus and Mini, the soundbar's four built-in high-precision microphones measure the room and calibrate the complete system including any connected AMBEO Subs.
This keeps the soundbar, subwoofer and AMBEO processing working as one integrated system.
Calibration Is Part of the AMBEO System
The AMBEO Sub itself is not specified with a built-in calibration microphone. With the AMBEO Soundbar Plus and Mini, room measurement is carried out by the soundbar's built-in microphones. With the AMBEO Soundbar Max, calibration uses the Max's supplied external microphone.
Wired Connection
A mono RCA input is provided for conventional wired operation.
This allows the AMBEO Sub to receive a line-level subwoofer signal through a standard mono RCA cable rather than relying exclusively on the dedicated AMBEO wireless connection.
Using the AMBEO Sub With the Soundbar Max
The original AMBEO Soundbar Max does not contain the wireless subwoofer architecture used by the later Plus and Mini.
Instead, connect the Max's SW PRE OUT directly to the AMBEO Sub's RCA input using a mono RCA cable.
The Max then includes the connected subwoofer within its own room-calibration calculations.
Recalibrate the Max After Adding the Sub
Sennheiser recommends repeating the Soundbar Max room calibration whenever a subwoofer is connected or disconnected.
This allows the Max to calculate its low-frequency behaviour with the additional subwoofer present rather than continuing to use a calibration profile created for the soundbar operating by itself.
Wireless or Wired?
Wireless AMBEO Connection
- AMBEO Soundbar Plus
- AMBEO Soundbar Mini
- Bluetooth Low Energy 5.2
- LC3 codec
- Up to 10m specified range
- Up to four AMBEO Subs
- Managed through Smart Control
- System calibrated by the soundbar
- No analogue signal cable required
Wired RCA Connection
- AMBEO Soundbar Max
- AMBEO Soundbar Plus if desired
- Compatible equipment with subwoofer output
- Mono RCA connection
- Signal cable required
- One wired connection
- Useful for permanent installations
- Not dependent on wireless range
- RCA cable not supplied
Compatible With More Than One AMBEO Soundbar
The same AMBEO Sub can therefore be used across the current Sennheiser soundbar family, but the connection method is not identical for every model.
This is particularly important if an existing AMBEO owner upgrades or changes soundbars at a later date.
AMBEO Soundbar Plus and Sub
The Soundbar Plus already reaches a specified 38Hz using its pair of built-in 4-inch woofers.
Adding the AMBEO Sub extends the system down to 27Hz while also moving the deepest bass workload onto a dedicated 8-inch driver and 350W amplifier.
This can provide greater physical scale and low-frequency headroom, particularly with demanding film soundtracks.
AMBEO Soundbar Mini and Sub
The Soundbar Mini reaches a specified 43Hz from its very compact enclosure.
Pairing it with an AMBEO Sub extends the system substantially further into the lowest frequencies while retaining the Mini's discreet physical footprint beneath the television.
For a smaller room where a large soundbar is impractical, the Mini and Sub combination can therefore make a great deal of sense.
AMBEO Soundbar Max and Sub
The AMBEO Soundbar Max already offers unusually deep bass for a soundbar, reaching a specified 30Hz from six internal 4-inch bass and midrange drivers.
Adding the AMBEO Sub is therefore less about correcting a shortage of bass and more about providing additional low-frequency output and physical impact in larger rooms or more demanding installations.
Where Should the Subwoofer Go?
Subwoofer placement can make a substantial difference because low frequencies interact strongly with walls, floors and room dimensions.
Good starting locations may include:
- Near the front of the room
- Beside the television cabinet
- Near the Soundbar
- Along a side wall
- Another location identified through listening and calibration
The wireless connection available with the Plus and Mini gives you considerably more flexibility to experiment without having to run a long audio cable across the room.
Avoid Automatically Putting It in a Corner
A corner can increase perceived bass output because several room boundaries reinforce the lowest frequencies simultaneously.
That can be useful, but it can also exaggerate particular frequencies and produce bass that sounds heavy or uneven.
Do not assume the most convenient corner is automatically the best acoustic position.
Allow Space Around the Cabinet
The AMBEO Sub is relatively compact but still needs sensible ventilation and enough room for its power and signal connections.
Its current specified dimensions are approximately 27.7cm wide, 36.9cm high and 27.4cm deep.
Allow extra clearance behind the cabinet for cables and avoid positioning it where vents or connections may be obstructed.
8.2kg Construction
The AMBEO Sub weighs approximately 8.2kg.
That mass helps give the driver and amplifier a stable enclosure from which to operate while remaining manageable enough to reposition during setup.
Automatic Standby
The Sub incorporates power-saving standby behaviour.
When wirelessly connected to a compatible AMBEO Soundbar, it can automatically enter standby after the soundbar moves into its ECO mode.
Wired operation also incorporates automatic standby after a period without a signal.
Smart Control Integration
When used wirelessly as part of a compatible AMBEO Soundbar system, setup and management are handled through Sennheiser's Smart Control app.
The app can guide you through connecting additional AMBEO Subs and the subsequent calibration of the complete system.
Firmware Updates
Sennheiser continues to provide firmware support for the AMBEO system.
When the Sub is integrated with the Soundbar Plus or Mini, firmware updates can be managed as part of the AMBEO system through the Smart Control platform.
More Bass Is Not Always Better
A correctly integrated subwoofer should not constantly draw attention to itself.
The aim is for the main system and subwoofer to behave as though they are one larger loudspeaker system rather than hearing an obvious separate box producing bass from somewhere in the room.
Good integration should improve:
- Low-frequency extension
- Film impact
- Scale
- Weight
- Room-filling capability
- Consistency across the listening area
Who Is the AMBEO Sub For?
- AMBEO Soundbar Plus owners wanting deeper bass
- AMBEO Soundbar Mini owners wanting deeper bass
- AMBEO Soundbar Max owners wanting additional low-frequency output
- Film and home cinema enthusiasts
- Listeners wanting bass extension down to 27Hz
- Larger rooms needing greater low-frequency headroom
- Systems where physical soundtrack impact matters
- Customers wanting wireless subwoofer placement with Plus or Mini
- Customers considering a multi-sub AMBEO system
- Listeners wanting a compact sealed active subwoofer
Who Is It Not For?
- Customers assuming the Soundbar Max supports wireless AMBEO Sub pairing
- Systems requiring a speaker-level subwoofer input
- Customers wanting a passive subwoofer
- Users expecting a completely cable-free installation, as mains power is still required
- Anyone assuming four subwoofers are necessary in an ordinary living room
Key Features
- Sennheiser AMBEO Sub
- Model SW02
- Active subwoofer
- Sealed cabinet
- Single 8-inch driver
- 200mm woofer
- Long-throw design
- Cellulose-cone driver
- 350W RMS amplifier
- Class D amplification
- Dual-core SoC processing
- 27Hz to 80Hz frequency response
- Wireless AMBEO connectivity
- Bluetooth Low Energy 5.2
- LC3 wireless codec
- Up to 10m wireless range
- Wireless AMBEO Soundbar Plus compatibility
- Wireless AMBEO Soundbar Mini compatibility
- Up to four wireless AMBEO Subs
- Mono RCA wired input
- Wired AMBEO Soundbar Max compatibility
- Wired AMBEO Soundbar Plus compatibility
- Room calibration through compatible AMBEO Soundbar system
- Smart Control integration with compatible AMBEO system
- Automatic standby
- 100 to 240V universal mains operation
- Approximately 27.7cm width
- Approximately 36.9cm height
- Approximately 27.4cm depth
- Approximately 8.2kg weight
- Black finish
Frequently Asked Questions
Is the Sennheiser AMBEO Sub still current?
Yes. It remains part of Sennheiser's current AMBEO home cinema range.
Is this product a soundbar?
No. The AMBEO Sub is an active subwoofer designed to extend low-frequency performance.
What size driver does it use?
A single 8-inch / 200mm long-throw cellulose-cone woofer.
How powerful is the AMBEO Sub?
Sennheiser specifies 350W RMS from its built-in Class D amplifier.
How low does it go?
The specified frequency response extends down to 27Hz at -3dB.
What is the upper frequency limit?
80Hz at -3dB.
Is the cabinet ported?
No. The AMBEO Sub uses a sealed enclosure.
Does the AMBEO Sub connect wirelessly?
Yes, with compatible AMBEO Soundbar Plus and Mini models.
Does it connect wirelessly to the AMBEO Soundbar Max?
No. The Soundbar Max requires a wired mono RCA connection to the AMBEO Sub.
Can I use the AMBEO Sub with the Soundbar Plus?
Yes. It can be connected wirelessly or, if preferred, the Soundbar Plus also provides a wired RCA subwoofer output.
Can I use it with the AMBEO Soundbar Mini?
Yes. The Mini supports wireless AMBEO Sub connection.
How many AMBEO Subs can I connect?
The AMBEO Soundbar Plus and Mini support up to four wirelessly connected AMBEO Subs.
Do I need four subwoofers?
No. One AMBEO Sub will be sufficient for many rooms. Multiple Subs can be useful for larger spaces or improving bass consistency across several listening positions.
What wireless system does the AMBEO Sub use?
Sennheiser specifies Bluetooth Low Energy 5.2 with the LC3 codec for its dedicated AMBEO Sub connection.
What is the wireless range?
Up to approximately 10 metres under suitable conditions.
Does wireless mean it needs no cables?
No. Wireless refers to the audio connection. The AMBEO Sub still requires a mains power cable.
Does it have an RCA input?
Yes. A mono line-level RCA input is provided.
Is an RCA cable supplied?
No RCA audio cable is listed in the supplied package contents.
Does the AMBEO Sub have a built-in calibration microphone?
Sennheiser's current technical specification does not list a calibration microphone within the AMBEO Sub itself. Room calibration is performed by the compatible AMBEO Soundbar system.
How is it calibrated with the Soundbar Plus?
The Plus uses its four built-in calibration microphones to measure the complete system including any connected AMBEO Subs.
How is it calibrated with the Soundbar Mini?
The Mini also uses its built-in room-calibration microphones to measure the soundbar and connected AMBEO Subs together.
How is it calibrated with the Soundbar Max?
The Sub connects to the Max by RCA and the Max's supplied external room-calibration microphone is then used to recalibrate the system.
Should I recalibrate after adding a Sub?
Yes. The compatible AMBEO Soundbar should be recalibrated so the additional low-frequency capability can be included in the system calculation.
Can I move the Sub after calibration?
You can, but if its position is changed significantly it is sensible to repeat the room calibration.
Where should I put the AMBEO Sub?
There is no single correct position for every room. Start near the front of the room and experiment with placement while using the AMBEO calibration system to optimise the final setup.
Should I put it in a corner?
A corner can increase bass output, but it can also exaggerate room resonances. The best position depends on the individual room.
Can it be controlled through the Sennheiser app?
When integrated wirelessly with a compatible AMBEO Soundbar, connection and system setup can be managed through Sennheiser Smart Control.
Does the AMBEO Sub automatically go into standby?
Yes. Automatic standby behaviour is supported, with timing depending on whether the Sub is operating wirelessly or through a wired connection.
How big is it?
Approximately 27.7cm wide, 36.9cm high and 27.4cm deep.
How much does it weigh?
Approximately 8.2kg.
What comes in the box?
The AMBEO Sub is supplied with its power cord, instruction manual, Quick Guide and safety and compliance documentation.
Related Sennheiser Products and Audio T Guides
Why Buy the Sennheiser AMBEO Sub From Audio T?
Subwoofer performance depends heavily on the room, placement and the system it is being added to. Audio T can help you decide whether your AMBEO system needs an additional Sub at all, where it should be positioned and whether a single or multi-sub arrangement makes sense for your room.
We can also advise on wireless pairing with the AMBEO Soundbar Plus and Mini, wired connection to the AMBEO Soundbar Max, room calibration and getting the bass properly integrated rather than simply turning it up.
- Friendly home cinema advice
- AMBEO system guidance
- Subwoofer demonstrations where available
- Wireless AMBEO pairing advice
- Soundbar Max wired connection guidance
- Room calibration advice
- Subwoofer positioning guidance
- Single and multi-sub advice
- Bass integration guidance
- Home cinema system comparisons
- Home demonstrations where available
- Ongoing after-sales support
Contact your local Audio T store if you would like help adding an AMBEO Sub to your home cinema system or deciding where it should be positioned.