Audio T Verdict
The REL No.32 is a true flagship subwoofer, designed for systems where every part of the low-frequency performance must match the quality, scale and control of the main loudspeakers.
Its 380mm pure carbon-fibre driver, 1,000W NextGen 7 amplifier and 15Hz extension deliver tremendous weight and physical authority, but the No.32 is not simply about producing more bass.
Properly positioned and adjusted, it expands the scale, space and realism of music while retaining the speed and delicacy required to integrate with the finest loudspeakers.
High Level, low-level and dedicated LFE connections make it equally relevant to reference stereo systems and ambitious home cinemas. The supplied remote and dual parametric filters also allow unusually precise adjustment from the listening position.
At approximately 85kg, this is an exceptionally substantial product requiring careful delivery and installation planning. For systems capable of revealing its performance, however, the No.32 represents the full expression of REL’s Reference Series engineering.
REL No.32 Reference Series Subwoofer
The REL No.32 is the flagship model in REL’s Reference Series and represents the culmination of more than three decades of subwoofer development.
It combines a front-firing 380mm pure carbon-fibre driver, 1,000W RMS NextGen 7 amplifier, sealed cabinet and low-frequency extension reaching 15Hz at the stated minus 6dB point.
The No.32 can operate as a single reference subwoofer, as part of a stereo pair or within an advanced vertically stacked REL Reference line array.
REL’s Flagship Reference Subwoofer
The No.32 sits above the
REL No.31
and is intended for customers seeking the greatest scale, extension and dynamic capability available within REL’s range.
REL has not treated it as a larger version of a conventional subwoofer. Its driver, amplifier, controls, cabinet and line-array capability have been developed as a complete Reference system.
Its performance is intended to support high-end loudspeakers and amplification without slowing the system, masking detail or making the subwoofer obvious as a separate source.
380mm Pure Carbon-Fibre Driver
The No.32 uses a front-firing 380mm long-throw driver constructed entirely from carbon fibre.
A large inverted carbon-fibre centre cap is bonded to the main cone, reinforcing the structure and helping it remain stable during substantial low-frequency movement.
Carbon fibre combines low moving mass with high rigidity and useful self-damping properties, helping the driver reproduce both powerful effects and subtle changes in musical texture.
The driver is mounted within a rigid die-cast alloy chassis that provides a stable mechanical foundation for the cone, suspension and motor assembly.
100mm Driver Travel
The No.32 driver suspension permits approximately 100mm of total fore-and-aft travel.
This substantial excursion allows the large cone to move the volume of air required for deep, high-output bass without depending on a reflex port or passive radiator.
The suspension, voice coil and motor system are designed to retain control throughout this movement, helping the No.32 combine physical impact with fast transient response.
Closed-Box, Front-Firing Design
The No.32 uses a sealed cabinet with no reflex port or passive radiator.
Air trapped within the enclosure helps control the driver’s movement, supporting a fast response and gradual low-frequency roll-off.
The absence of a reflex port also removes the possibility of port airflow noise during demanding music and cinema passages.
Its front-firing configuration allows the cabinet to operate on a variety of firm floor surfaces without requiring working clearance beneath a down-firing driver.
15Hz Low-Frequency Extension
REL specifies low-frequency extension to 15Hz at minus 6dB.
This allows the No.32 to reproduce extremely deep musical and cinematic information while adding scale and authority to the complete frequency range.
The extension achieved at the listening position will also be influenced by room dimensions, placement, seating location and the settings used on the subwoofer.
The goal is not to make every recording sound bass-heavy. Properly adjusted, the No.32 should extend the system naturally and reveal low-frequency information only when it is present.
1,000W NextGen 7 Class D Amplifier
A 1,000W RMS NextGen 7 Class D amplifier powers the 380mm carbon-fibre driver.
The amplifier provides the current delivery and dynamic headroom required for sudden musical transients, deep orchestral information and powerful home cinema effects.
Its output is rated as continuous RMS power rather than a short-duration peak figure.
The No.32 implementation includes revised limiting, higher gain and carefully selected components intended to preserve speed, tonal colour and dynamic contrast.
Advanced Output Limiting
The amplifier’s limiting system is designed to allow the No.32 to operate close to its intended performance envelope without introducing obvious compression.
Rather than making loud passages sound mechanically restricted, the system helps preserve contrast, timing and a sense of ease.
Protection operates in the background while allowing the large driver and amplifier to deliver substantial output when required.
Fully Electronic Protection
REL’s electronic Set-Safe system monitors the amplifier during operation.
Additional protection is provided against DC faults and output short circuits.
These systems operate automatically but do not replace correct connection, ventilation and installation practices.
Dual Parametric Filters
Two adjustable parametric filters allow the No.32 to be fine-tuned for the loudspeakers, room and listening position.
Filter A can be used to refine the deepest part of the subwoofer’s response, helping achieve flatter and more extended low-frequency performance.
Filter B can assist with the upper part of the subwoofer’s range, helping refine the transition between the No.32 and the main loudspeakers.
The filters may also help reduce a specific room-related bass excess without applying broad correction across the complete low-frequency range.
Parametric adjustment should be treated as a final stage after sensible positioning, phase, crossover and gain settings have been established.
REL Reference Remote Control
The supplied REL Reference Remote allows the principal setup controls to be adjusted from the listening position.
Separate controls are provided for High Level or low-level gain, crossover frequency and the dedicated .1/LFE channel.
Metal toggle switches provide access to remote power, phase adjustment and the two parametric filters.
The phase control allows selection between 0 and 180 degrees, while filters A and B can be engaged and adjusted without repeatedly moving between the listening seat and the subwoofer.
Once the No.32 has been correctly configured, the remote can be set aside until the room, equipment or system layout changes.
REL High Level Connection
REL’s preferred connection for many conventional stereo systems is the supplied High Level Neutrik Speakon cable.
This connection receives the same signal and sonic character being delivered by the main amplifier to the loudspeakers.
The main speakers remain connected directly to the amplifier and continue to receive their normal full-range signal. The No.32 is added alongside them and adjusted to support their natural low-frequency roll-off.
A nominal 10-metre Neutrik Speakon High Level cable is supplied with the No.32.
Check High Level Compatibility Before Connection
The correct High Level wiring arrangement depends on the design of the connected amplifier.
Balanced, bridged, differential, Class D and certain specialist amplifier designs may require a different grounding arrangement from a conventional stereo amplifier.
Do not assume that a wiring method used with one amplifier will be suitable for another. Check the amplifier instructions or contact Audio T before connecting the High Level cable whenever there is uncertainty.
Stereo Low-Level RCA Inputs
Two RCA sockets allow the No.32 to receive a stereo low-level signal from a suitable pre-amplifier, integrated amplifier, processor or active loudspeaker system.
The source must provide variable outputs that follow the main system volume.
Low-level connection can be particularly useful with active loudspeakers and equipment that does not permit a suitable High Level connection.
Dedicated RCA LFE Input
A dedicated RCA LFE input connects to the subwoofer output of a compatible AV receiver or surround processor.
This carries the separate low-frequency effects channel used by film, television, concert and multichannel game soundtracks.
The No.32 provides independent .1/LFE gain adjustment, allowing its home cinema output to be configured separately from the High Level or stereo low-level connection.
Balanced XLR LFE Input
A balanced XLR LFE input is provided for compatible surround processors and professionally planned installations.
Balanced connection can be useful where the processor is positioned a considerable distance from the No.32 or the cable route passes close to other electrical equipment.
The connected processor must provide a suitable variable balanced subwoofer output.
Simultaneous Music and Cinema Connection
The No.32 can use its High Level or stereo low-level connection for music while also remaining connected to the dedicated LFE output of a home cinema processor.
The two signal paths provide separate gain adjustment, allowing the No.32 to integrate naturally with the main loudspeakers during stereo listening while reproducing the dedicated .1 channel during films.
This arrangement is particularly useful where the same main loudspeakers and power amplifier are shared between a stereo system and home cinema processor.
Signal Output Connections
The No.32 provides High Level Speakon, low-level RCA, balanced XLR LFE and balanced XLR line outputs.
These can be used to pass the relevant signal to an additional compatible REL when building a stereo pair, multiple-subwoofer system or Reference line array.
Every No.32 remains independently powered and retains its own gain, crossover, phase and filter settings.
REL Airship II Wireless Compatibility
The No.32 is compatible with the optional
REL Airship II wireless system
.
Airship II can transmit High Level and LFE signals using REL’s dedicated 5.8GHz wireless connection, providing greater freedom when a conventional cable route would be difficult.
High Level and LFE signals can operate concurrently, preserving the No.32’s separate music and home cinema connection options.
The Airship II receiver can mount directly to the amplifier panel of the No.32, avoiding the need to leave the receiver loose behind the cabinet.
Wireless Does Not Remove Every Cable
Airship II carries the audio signal only.
The transmitter still connects to the amplifier or processor, the wireless components require power and the No.32 continues to require its normal mains connection.
Bassline Blue High Level Cable
A standard High Level cable is supplied with the No.32.
The optional
REL Bassline Blue High Level cable
provides an upgraded connection for compatible amplifiers and REL subwoofers.
Bassline Blue is available in different versions and lengths, including configurations developed for compatible Naim amplifiers.
Confirm the correct cable version and amplifier wiring arrangement before ordering.
Positioning the REL No.32
Begin with the No.32 positioned along the same wall as the main loudspeakers.
A corner can increase output and low-frequency extension, while moving the cabinet away from the corner may reduce excessive bass created by the room.
The No.32 should not be enclosed tightly within furniture or positioned where its front driver, rear amplifier panel or ventilation can be obstructed.
Its approximately 85kg weight and 816mm cabinet depth mean that delivery access, floor suitability and the final cable route should be considered before installation.
Plan Delivery and Installation Carefully
The No.32 measures approximately 743mm wide, 540mm high and 816mm deep and weighs approximately 85kg.
Allow additional space behind the cabinet for plugs, cable bends, ventilation and access to the amplifier panel.
Several people or appropriate handling equipment will be required when unpacking, moving or repositioning the subwoofer.
Check doorways, staircases, corners and the intended delivery route before ordering.
Initial Stereo Setup
- Place the No.32 along the same wall as the main loudspeakers.
- Switch off the complete system before making any connections.
- Connect the supplied High Level cable or suitable stereo low-level interconnect.
- Begin with conservative crossover and gain settings.
- Select the phase setting that produces the strongest and most coherent bass at the listening position.
- Adjust the crossover so the No.32 supports the natural roll-off of the main loudspeakers.
- Increase the gain until the added weight is clearly audible.
- Reduce the gain slightly until the subwoofer no longer draws attention to itself.
- Use the parametric filters only after placement, phase, crossover and gain have been established.
- Complete the setup using familiar music from the normal listening position.
Initial Home Cinema Setup
- Connect the AV receiver or processor’s subwoofer output to the appropriate RCA or balanced XLR LFE input.
- Set the No.32’s dedicated .1/LFE gain conservatively.
- Configure suitable loudspeaker crossover points within the AV processor.
- Run the processor’s measurement and room-correction procedure where provided.
- Review the measured subwoofer distance, level and crossover settings.
- Check that the No.32 does not overpower dialogue or the main loudspeakers.
- Complete the setup using familiar film, concert and music material.
Single No.32, Stereo Pair or Line Array?
Single No.32
- Exceptional output and extension from one cabinet
- Simplest Reference Series installation
- Suitable for high-end stereo systems
- Powerful dedicated home cinema LFE performance
- Provides a foundation for future expansion
Stereo Pair
- One No.32 supports each main loudspeaker
- Can improve left-to-right low-frequency symmetry
- Provides greater combined dynamic headroom
- May improve bass consistency within the room
- Each subwoofer requires individual setup
Reference Line Array
- Typically uses three matching No.32 units per side
- Five per side may suit exceptionally tall rooms
- Creates a floor-to-ceiling low-frequency presentation
- Every subwoofer retains independent adjustment
- Requires substantial space and professional planning
REL Reference Line Arrays
The No.32 is designed to support vertically stacked Reference line-array systems.
A typical stereo Reference array uses three matching subwoofers beside each main loudspeaker, although exceptionally tall rooms may accommodate five units per side.
Every subwoofer within the stack retains independent crossover and gain adjustment, allowing the lower, middle and upper units to be configured according to their individual positions.
The purpose is not simply to increase volume. A correctly designed array can create a more even floor-to-ceiling wavefront while increasing the apparent height, scale and physical presence of the reproduced soundstage.
Reference line arrays require suitable room dimensions, significant floor space, dedicated mounting hardware, careful signal distribution and expert installation.
Supplied Line Array Mounting Hardware
REL supplies line-array mounting hardware with the No.32.
The hardware is intended to secure matching No.32 cabinets when they are installed in an approved vertical configuration.
The combined height and weight of a complete stack mean that the installation must be planned carefully and completed in accordance with REL’s instructions.
Do not attempt to improvise alternative brackets, fixings or supports.
Bassline Blue Line Array Connectors
The
REL Bassline Blue Line Array Connectors
can pass the High Level signal between compatible REL subwoofers within a vertical stack.
This allows one main High Level cable to run from the amplifier to the lower subwoofer, with shorter connectors carrying the signal to the units above.
A pair of connectors is required for each vertical level when building matching left and right arrays.
The number of connectors and mounting components required should be confirmed as part of the complete line-array design.
REL No.31 or No.32?
REL No.31
- 300mm pure carbon-fibre driver
- 900W RMS NextGen 7 amplifier
- 17Hz extension at minus 6dB
- Approximately 638 x 435 x 720mm
- Approximately 52kg net weight
- More manageable Reference cabinet
View the REL No.31
REL No.32
- 380mm pure carbon-fibre driver
- 1,000W RMS NextGen 7 amplifier
- 15Hz extension at minus 6dB
- Approximately 743 x 540 x 816mm
- Approximately 85kg net weight
- REL’s flagship Reference subwoofer
Both models provide Reference Remote control, High Level and LFE connectivity, dual parametric filtering, Airship II compatibility and support for vertically stacked Reference arrays.
The choice should be based on the main loudspeakers, room, required scale and available installation space rather than amplifier output alone.
Curved Reference Cabinet
The No.32 uses the curved cabinet form associated with REL’s Reference range.
The top surface curves down towards the rear corners, requiring complex construction and finishing but giving the large cabinet a less conventional appearance.
The cabinet’s curved panels and substantial internal structure provide the mechanical stability required to support the large driver and control unwanted resonance.
Substantial Internal Construction
The rear internal backing plate is more than half an inch thick and is shaped to follow the curved interior of the cabinet.
This creates a rigid foundation for the amplifier panel and helps the enclosure withstand the forces generated by the 380mm driver.
REL states that the cabinet requires approximately three weeks of labour to complete.
Triple-Plated Lifting Handles
Triple-plated steel handles are recessed into elliptical sections on the sides of the cabinet.
These provide secure gripping points when the No.32 must be moved, although its approximately 85kg weight still requires several people or suitable handling equipment.
The handles should not be treated as a substitute for safe lifting practices or an appropriate delivery plan.
Reference Badge and Driver Detailing
The No.32 badge combines carbon fibre with a polished cast-alloy surround finished in three layers of plating.
This reflects the materials used within the driver while giving the flagship model a distinctive visual detail.
The plated elements and deep gloss cabinet are intended to complement similarly finished reference loudspeakers and equipment.
Twelve-Coat Piano-Black Lacquer
The cabinet is finished in twelve coats of piano-black lacquer.
The deep gloss finish reflects the time and craftsmanship involved in building the No.32 and helps the substantial cabinet appear more refined within a dedicated listening room.
Use a clean, soft microfibre cloth for routine care and avoid abrasive cleaners that could mark the lacquer.
System Matching
Well Suited To
- Reference stereo systems
- Medium-sized and large listening rooms
- High-performance full-range loudspeakers
- Active speakers with suitable variable outputs
- Premium AV receivers and surround processors
- Combined stereo and home cinema installations
- Single and stereo-pair configurations
- REL Reference line-array systems
- Airship II wireless installations
Check Before Installation
- The cabinet weighs approximately 85kg
- Allow space behind the stated 816mm depth
- Check the complete delivery route before ordering
- Confirm the correct High Level amplifier wiring
- RCA and XLR interconnects are not supplied
- Airship II is an optional wireless system
- Do not obstruct the driver or amplifier panel
- Retain access to the mains connection
- Line arrays require substantial vertical space
- Professional handling and installation are strongly recommended
Setup Guidance
- Begin along the same wall as the main speakers
- Establish phase before final crossover adjustment
- Keep the initial gain setting conservative
- Blend the No.32 rather than making it obvious
- Use the LFE connection separately for home cinema
- Apply parametric filtering only after basic setup
- Adjust from the normal listening position
- Test with familiar music and film material
- Recheck the setup after the system has been used
Browse our
home cinema subwoofers
,
home cinema amplifiers
,
home cinema speakers
,
wireless accessories
and
subwoofer and system cables
, or explore the
REL range at Audio T
.
Key Features
- Flagship REL Reference Series active subwoofer
- Closed-box cabinet with front-firing driver
- 380mm long-throw pure carbon-fibre cone
- Inverted carbon-fibre centre cap
- Die-cast alloy driver chassis
- Approximately 100mm of total fore-and-aft driver travel
- 15Hz low-frequency extension at minus 6dB
- 1,000W RMS NextGen 7 Class D amplifier
- Advanced wide-envelope output limiting
- Dual adjustable parametric filters
- Supplied REL Reference Remote
- High Level Neutrik Speakon input
- Two stereo low-level RCA inputs
- Dedicated RCA LFE input
- Balanced XLR LFE input
- High Level Speakon signal output
- Low-level RCA signal output
- Balanced XLR LFE and line outputs
- Simultaneous High Level and LFE operation
- Compatible with REL Airship II
- Suitable for single and stereo-pair systems
- Supports vertically stacked Reference line arrays
- Line-array mounting hardware supplied
- Curved and internally reinforced Reference cabinet
- Triple-plated recessed steel lifting handles
- Carbon-fibre and plated-alloy badge
- Twelve-coat piano-black lacquer finish
- Fully electronic Set-Safe protection
- DC fault and output-short protection
- Three-year REL warranty, subject to current terms
Frequently Asked Questions
Is the REL No.32 intended mainly for music or home cinema?
It is designed for both. High Level and stereo low-level inputs support music systems, while RCA and balanced XLR LFE inputs provide dedicated home cinema connection.
What is the difference between the No.31 and No.32?
The No.31 uses a 300mm driver, 900W amplifier and smaller 52kg cabinet. The No.32 uses a 380mm driver, 1,000W amplifier, deeper 15Hz extension and a substantially larger 85kg cabinet.
Does the No.32 include a High Level cable?
Yes. A Neutrik Speakon High Level cable measuring approximately 10 metres is supplied.
Can the No.32 connect to active loudspeakers?
Yes, provided the active system offers suitable variable low-level outputs. The left and right RCA low-level inputs can then be used.
Can High Level and LFE connections be used together?
Yes. This allows the No.32 to support the main loudspeakers during stereo playback while also reproducing the dedicated .1 channel from a home cinema processor.
Can the No.32 connect using balanced XLR?
Yes. It provides a balanced XLR LFE input for a compatible AV processor, together with balanced LFE and line outputs for suitable expanded systems.
Can the No.32 operate wirelessly?
Yes. It is compatible with the optional REL Airship II system, which can transmit High Level and LFE signals.
Does it include a remote control?
Yes. The supplied REL Reference Remote allows gain, crossover, phase and dual parametric filter settings to be adjusted from the listening position.
Can two No.32 subwoofers be used as a stereo pair?
Yes. One No.32 can be positioned beside each main loudspeaker, with every subwoofer independently adjusted for its channel and room position.
Can No.32 subwoofers be vertically stacked?
Yes. A typical Reference line array uses three matching units per side, while exceptionally tall rooms may accommodate five. The correct mounting hardware, space and professional installation are essential.
Is the mounting hardware included?
REL lists line-array mounting hardware among the supplied No.32 accessories. Additional signal connectors and installation components may still be required for a complete array.
What do the dual parametric filters do?
They allow selected parts of the low-frequency response to be adjusted more precisely, helping refine deep-bass extension, loudspeaker integration and specific room-related bass excesses.
Is an RCA or XLR interconnect included?
No. The appropriate low-level or LFE interconnect should be selected separately according to the source equipment and required cable route.
How large and heavy is the No.32?
It measures approximately 743 x 540 x 816mm and weighs 85kg. Additional space should be allowed behind the cabinet for cables, ventilation and access to the amplifier panel.
Can one person safely move the No.32?
No. Its approximately 85kg weight and substantial cabinet dimensions mean several people or suitable handling equipment should be used when unpacking, positioning or moving it.
Why Buy From Audio T?
- Reference subwoofer and loudspeaker-matching advice
- Comparison with the more compact REL No.31
- High Level amplifier-compatibility guidance
- Low-level, RCA LFE and balanced XLR connection advice
- Combined stereo and home cinema system planning
- Single and stereo-pair setup assistance
- REL Reference line-array planning
- Room-positioning and phase-setting guidance
- Crossover, gain and parametric filter support
- Airship II wireless compatibility advice
- Bassline Blue cable recommendations
- Delivery-route and installation planning
- Ongoing system and after-sales support
Contact your local Audio T store
to discuss demonstrating, delivering and integrating the REL No.32 within your stereo or home cinema system.