Audio T Verdict
The REL T/9x is the flagship of the standard Serie T/x range and one of REL’s strongest all-rounders for music and home cinema.
Its front-firing 250mm FibreAlloy active driver, matching 250mm down-firing passive radiator and 300W Class A/B amplifier deliver considerably greater scale and authority than the smaller T/5x and T/7x.
Despite its output, the T/9x is not designed simply to make bass louder. Properly positioned and adjusted, it can improve the weight, timing, openness and physical scale of the complete system without becoming obvious as a separate sound source.
High Level, low-level and dedicated LFE inputs make it suitable for conventional stereo systems, active loudspeakers and home cinema, while the optional REL Arrow system provides wireless High Level or LFE connection.
REL T/9x Serie T/x Subwoofer
The REL T/9x is a high-performance active subwoofer developed for music systems, television, gaming and home cinema.
It combines a front-firing 250mm FibreAlloy active driver with a matching 250mm down-firing passive radiator, a 300W RMS Class A/B amplifier and low-frequency extension reaching 27Hz at the stated minus 6dB point.
The T/9x can be used as a powerful single subwoofer, as part of a stereo pair or within a properly planned multi-subwoofer REL 3D home cinema system.
The Flagship Standard Serie T/x Model
The T/9x sits above the T/5x and T/7x within REL’s standard Serie T/x range.
Its larger active driver, increased amplifier output and greater cabinet volume provide substantially more scale and dynamic headroom than the smaller models.
The T/9x remains compact enough to integrate into many domestic listening rooms while offering the output required for larger loudspeakers and higher playback levels.
It is particularly well suited to medium-sized and larger rooms where the T/7x may not provide sufficient effortless output.
250mm FibreAlloy Active Driver
The front-firing active driver uses REL’s 250mm long-throw FibreAlloy cone construction.
Its lightweight composite cone is reinforced by an inverted alloy centre cap, providing the stiffness required for controlled bass without adding unnecessary moving mass.
The revised suspension allows greater controlled movement than the previous generation, helping the driver reproduce sudden musical transients and demanding cinema effects without becoming loose or indistinct.
A rigid steel chassis provides a stable mechanical foundation for the driver, voice coil and suspension.
250mm Down-Firing Passive Radiator
A matching 250mm long-throw passive radiator is positioned beneath the cabinet.
It uses FibreAlloy cone material with an inverted alloy centre cap and steel chassis.
The passive radiator responds to pressure created inside the cabinet by the active driver, supporting deeper extension and greater output without requiring an open reflex port.
Because the passive radiator does not have its own voice coil or amplifier, its movement is controlled by the active driver, cabinet air pressure and carefully selected suspension.
Front-Firing Active and Down-Firing Passive Design
The combination of matching 250mm active and passive drivers allows the T/9x to move a considerable volume of air from a comparatively manageable cabinet.
The front-firing active driver provides speed, control and direct output into the room, while the down-firing passive radiator supports the deepest frequencies and larger dynamic changes.
The cabinet must remain upright on a firm and stable surface so that the passive radiator has the correct operating clearance beneath it.
Keep the Passive Radiator Clear
Do not place the T/9x on its side, obstruct the space beneath the cabinet or allow loose cables and objects to contact the down-firing passive radiator.
Thick or uneven floor coverings should not prevent the cabinet from standing securely or reduce the intended clearance beneath the subwoofer.
27Hz Low-Frequency Extension
REL specifies low-frequency extension to 27Hz at minus 6dB.
This gives the T/9x access to frequencies that many standmount and floorstanding loudspeakers cannot reproduce with useful output.
It can add greater weight and physical scale to bass instruments, drums, orchestral music, electronic recordings, television, films and games.
Room dimensions, placement, floor construction and the listening position will all influence the extension and output achieved in practice.
300W Class A/B Amplifier
A 300W RMS Class A/B amplifier powers the FibreAlloy active driver.
REL uses a high-current MOSFET amplifier design intended to provide the control, tonal richness and dynamic response required for music.
A substantial power supply helps the amplifier respond quickly when a recording or soundtrack demands a sudden increase in low-frequency output.
The output is rated as continuous RMS power rather than a short-duration peak figure.
Fully Analogue Input Filtering
The T/9x uses REL’s fast analogue filtering to blend its output with the main loudspeakers.
The High Level and low-level signal paths pass through an adjustable low-pass crossover, allowing the upper limit of the subwoofer’s output to be matched to the natural roll-off of the speakers.
Keeping the filtering within the analogue domain avoids unnecessary digital conversion within the normal signal path.
The T/9x does not include digital room correction or the dual parametric filters found on REL’s Reference models.
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 installation, ventilation and connection practices.
REL High Level Connection
REL’s preferred connection for many conventional stereo systems is the supplied High Level Neutrik Speakon cable.
This 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 T/9x 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 T/9x.
Check High Level Amplifier Compatibility
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.
Low-Level RCA Input
A single RCA low-level input allows the T/9x to receive a mono signal from a suitable pre-amplifier, integrated amplifier, processor or active loudspeaker system.
The source must provide a suitable variable output that follows the main system volume.
Low-level connection can be useful with active loudspeakers and equipment that does not permit a suitable High Level connection.
The low-level input shares the T/9x’s Hi/Low Level gain and crossover controls with the High Level input.
Dedicated RCA LFE Input
A separate RCA LFE input connects to the subwoofer output of a compatible AV receiver or surround processor.
This carries the dedicated low-frequency effects channel used by film, television, concert and multichannel game soundtracks.
The LFE input has its own level control and operates independently from the High Level or low-level music connection.
Bass management, loudspeaker crossover points, delay and channel level can normally be configured from the connected home cinema processor.
Simultaneous Music and Cinema Connection
The T/9x can use its High Level or low-level input 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 subwoofer 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 amplifier are shared between a stereo system and home cinema processor.
Separate Hi/Low and LFE Level Controls
The Hi/Low Level control adjusts the output produced from the High Level Speakon or low-level RCA input.
The separate .1/LFE Level control adjusts the output produced from the dedicated home cinema input.
These independent controls allow the T/9x to maintain one setting for music and another for home cinema without requiring repeated adjustment when changing source.
Variable Crossover Adjustment
The rear crossover control adjusts the upper frequency reproduced through the High Level and low-level signal paths.
It should be set so that the T/9x supports the natural low-frequency roll-off of the main loudspeakers without creating an obvious overlap in the upper bass.
The crossover does not control the dedicated LFE input because the home cinema processor normally handles the relevant filtering and bass management.
An excessively high setting can make the system sound thick or reveal the location of the subwoofer, while an excessively low setting may leave a gap between the speakers and subwoofer.
0 or 180-Degree Phase Adjustment
A two-position phase switch helps align the movement of the T/9x active driver with the main loudspeakers at the listening position.
The correct setting is normally the one that produces the strongest, fullest and most coherent bass.
Phase should be established before completing the final crossover and gain adjustment.
The best setting depends on the room, speaker position, subwoofer position and listening seat rather than the brand or size of the loudspeakers alone.
Standby and Always-On Operation
UK 220V to 240V versions of the T/9x include a standby-mode switch.
Standby mode allows the amplifier to enter a low-power state when no signal is detected, while always-on operation keeps the subwoofer ready for immediate use.
The preferred setting may depend on the system, listening habits and the level of signal reaching the input.
REL Arrow Wireless Compatibility
The T/9x is compatible with the optional
REL Arrow Wireless Transmitter
.
Arrow can transmit a REL High Level or home cinema LFE signal without using conventional Bluetooth or household Wi-Fi.
Its receiver docks directly into the wireless interface on the rear of the T/9x, avoiding the need for a separate audio cable between the receiver and subwoofer.
REL uses uncompressed wireless transmission to preserve timing, dynamics and the character of the incoming signal.
The stated wireless range is up to approximately 15.2 metres with a clear line of sight, although walls, furniture and wireless interference may reduce the practical distance.
Arrow Does Not Transmit the Low-Level RCA Input
REL Arrow provides High Level and LFE wireless connection.
It does not provide a conventional low-level RCA transmitter input. Systems requiring the T/9x’s low-level RCA connection should use a suitable wired interconnect.
The T/9x continues to require its normal mains connection when Arrow is used.
Bassline Blue High Level Cable
A standard 10-metre High Level cable is supplied with the T/9x.
The optional
REL Bassline Blue High Level cable
provides an upgraded connection for compatible amplifiers and REL subwoofers.
Bassline Blue is available in different lengths and connection versions, including configurations developed for compatible Naim amplifiers.
Confirm the correct cable version and amplifier wiring arrangement before ordering.
Positioning the REL T/9x
Begin with the T/9x positioned along the same wall as the main loudspeakers.
A corner position can increase output and low-frequency extension, while moving the cabinet away from the corner may reduce excessive room-related bass.
Small changes in position can make a significant difference, so the final location should be established by listening rather than appearance alone.
Avoid enclosing the subwoofer tightly within furniture or positioning it where the active driver, passive radiator, controls, wireless receiver or amplifier ventilation can be obstructed.
Initial Stereo Setup
- Place the T/9x along the same wall as the main loudspeakers.
- Switch off the complete system before making any connections.
- Connect the supplied High Level cable or a suitable low-level RCA interconnect.
- Begin with conservative crossover and Hi/Low Level settings.
- Select the phase setting that produces the strongest and most coherent bass at the listening position.
- Adjust the crossover so the T/9x supports the natural roll-off of the main loudspeakers.
- Increase the Hi/Low Level control until the additional bass is clearly audible.
- Reduce the level slightly until the subwoofer no longer draws attention to itself.
- 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 dedicated RCA LFE input.
- Set the T/9x .1/LFE Level control conservatively.
- Configure suitable loudspeaker crossover points within the processor.
- Run the processor’s measurement and room-correction procedure where provided.
- Review the measured subwoofer level, distance and crossover settings.
- Check that bass effects do not overpower dialogue or the main loudspeakers.
- Complete the setup using familiar film, television and music material.
Single T/9x or Stereo Pair?
Single T/9x
- Substantial output from one manageable cabinet
- Simplest positioning and connection arrangement
- Well suited to medium-sized and larger rooms
- Supports both music and home cinema systems
- Provides a foundation for later expansion
Stereo Pair
- One T/9x can support each main loudspeaker
- Can improve left-to-right low-frequency balance
- Provides greater combined dynamic headroom
- May improve bass consistency within the room
- Each subwoofer requires individual positioning and setup
Two subwoofers are not used purely to make the system louder. Correctly positioned and adjusted, a stereo pair can improve low-frequency balance, soundstage scale and integration with the main loudspeakers.
Can the T/9x Be Vertically Stacked?
The T/9x is not designed for vertical REL line-array stacking.
Its cabinet, feet and down-firing passive radiator require conventional upright floor placement with clear operating space beneath the enclosure.
Customers interested in an approved vertically stacked REL system should consider compatible Serie S or Reference models instead.
REL 3D Home Cinema Systems
REL’s 3D approach uses several subwoofers to support different areas of a surround system rather than relying entirely on one cabinet.
A dedicated Serie HT model may handle the main LFE channel, while T/x subwoofers support the front loudspeakers, centre speaker or rear region.
The output and flexible connectivity of the T/9x make it suitable for demanding roles within a properly planned multi-subwoofer installation.
The number and position of subwoofers should be planned around the room, speaker layout, processor and intended listening levels.
REL T/5x, T/7x or T/9x?
REL T/5x
- 200mm down-firing FibreAlloy active driver
- No passive radiator
- 125W RMS Class A/B amplifier
- 32Hz extension at minus 6dB
- Approximately 300 x 307 x 313mm
- Approximately 14.3kg net weight
- Most compact standard T/x model
View the REL T/5x
REL T/7x
- 200mm front-firing FibreAlloy active driver
- 250mm down-firing passive radiator
- 200W RMS Class A/B amplifier
- 30Hz extension at minus 6dB
- Approximately 356 x 320 x 363mm
- Approximately 17.5kg net weight
- Balanced size and performance
View the REL T/7x
REL T/9x
- 250mm front-firing FibreAlloy active driver
- 250mm down-firing passive radiator
- 300W RMS Class A/B amplifier
- 27Hz extension at minus 6dB
- Approximately 370 x 340 x 393mm
- Approximately 20.6kg net weight
- Flagship standard T/x model
All three models provide REL High Level, low-level and dedicated LFE inputs and are compatible with the optional Arrow wireless system.
The most appropriate model should be selected according to room size, loudspeaker capability, required playback level and available floor space rather than amplifier output alone.
REL T/9x or T/9x Special Edition?
REL T/9x
- Standard Serie T/x flagship
- 250mm FibreAlloy active driver
- 250mm FibreAlloy passive radiator
- 300W RMS Class A/B amplifier
- Piano Black, Gloss White and selected additional finishes
- Excellent all-round music and cinema performance
REL T/9x Special Edition
- Revised lighter active-driver assembly
- Faster response and slightly greater output
- Distinctive high-gloss colour options
- Retains the 300W Class A/B amplifier
- Retains High Level, low-level and LFE inputs
- Compatible with REL Arrow wireless connection
View the REL T/9x Special Edition
REL T/9x or Classic 98?
REL T/9x
- Modern gloss cabinet design
- Front-firing FibreAlloy active driver
- Down-firing passive radiator
- 300W Class A/B amplification
- Fast, precise and highly dynamic presentation
- Designed for music and home cinema
REL Classic 98
- Heritage-inspired walnut cabinet
- Single down-firing pulp-on-paper driver
- No passive radiator
- 300W Class D amplification
- Warmer and more relaxed presentation
- Particularly suited to classic-style music systems
View the REL Classic 98
Softly Rounded Cabinet
The T/9x cabinet uses softly rounded corners and clean surfaces to reduce its visual impact within a living room.
The revised proportions provide greater internal volume than the previous generation while avoiding the appearance of a simple equal-sided cube.
The curved edges and reinforced cabinet construction also help control unwanted panel vibration while giving the T/9x a more contemporary appearance.
Finish Options
REL officially lists Piano Black Lacquer and Gloss White Lacquer as the standard T/9x finishes.
Audio T may also offer Grey or other finish options according to current UK availability and remaining stock.
Five coats of hand-polished lacquer create a deep gloss surface intended to complement contemporary loudspeakers, furniture and system components.
Use a clean, soft microfibre cloth for routine care and avoid abrasive household cleaners that could mark the finish.
Matching Front Grille
A removable matching grille is supplied to protect the front-firing active driver.
The grille should be fitted carefully and removed by applying even pressure rather than pulling sharply from one corner.
Keep the grille and driver clear of liquids, cleaning sprays and objects that could damage the cone or suspension.
System Matching
Well Suited To
- Medium-sized and larger listening rooms
- Standmount and floorstanding loudspeakers
- High-performance stereo amplifiers
- Active speakers with a suitable variable output
- Stereo amplifiers using REL High Level connection
- AV receivers with an RCA subwoofer output
- Music, television, gaming and home cinema
- Single and stereo-pair installations
- REL Arrow wireless systems
Check Before Installation
- Allow clear operating space beneath the passive radiator
- Confirm the correct High Level amplifier wiring
- The low-level input is a single mono RCA connection
- An RCA interconnect is not supplied
- REL Arrow is an optional accessory
- The T/9x has no signal output connections
- The T/9x is not designed for vertical stacking
- Do not obstruct the driver or amplifier panel
- Finish availability may change
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 T/9x rather than making it obvious
- Use the dedicated LFE input for home cinema
- Review automated room-correction results
- Adjust from the normal listening position
- Test with familiar music and film material
- Recheck the setup after moving the cabinet
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 standard REL Serie T/x active subwoofer
- Front-firing active driver and down-firing passive radiator
- 250mm long-throw FibreAlloy active driver
- Inverted alloy active-driver centre cap
- Steel active-driver chassis
- 250mm long-throw FibreAlloy passive radiator
- Inverted alloy passive-radiator centre cap
- Steel passive-radiator chassis
- 27Hz low-frequency extension at minus 6dB
- 300W RMS Class A/B amplifier
- Fully analogue input filtering
- High Level Neutrik Speakon input
- Single low-level RCA input
- Dedicated RCA LFE input
- Separate Hi/Low Level and .1/LFE gain controls
- Variable low-pass crossover for High Level and low-level inputs
- 0 or 180-degree phase adjustment
- Standby-mode switch on UK 220V to 240V models
- Compatible with the optional REL Arrow wireless system
- Supports simultaneous music and home cinema connection
- Suitable for single and stereo-pair installations
- Suitable for REL 3D home cinema systems
- Softly rounded cabinet
- Piano Black, Gloss White and selected additional finishes
- Five coats of hand-polished lacquer on standard gloss finishes
- Matching front grille supplied
- 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 T/9x designed mainly for music or home cinema?
It is designed for both. High Level and low-level inputs support music systems, while the dedicated RCA LFE input provides home cinema connection.
What is the difference between the T/7x and T/9x?
The T/7x uses a 200mm active driver and 200W amplifier. The T/9x uses a larger 250mm active driver and 300W amplifier for greater extension, output and dynamic headroom.
What is the difference between the T/9x and T/9x Special Edition?
The Special Edition uses a revised, lighter active-driver assembly intended to provide a faster response and slightly greater output. It is also available in distinctive high-gloss colours.
Does the T/9x include a High Level cable?
Yes. A Neutrik Speakon High Level cable measuring approximately 10 metres is supplied.
Can the T/9x connect to active loudspeakers?
Yes, provided the active system offers a suitable variable mono low-level output. The T/9x has one low-level RCA input.
Can High Level and LFE connections be used together?
Yes. This allows the T/9x to support the main loudspeakers during music while also reproducing the dedicated .1 channel from a home cinema processor.
Does the T/9x have a balanced XLR input?
No. It provides High Level Speakon, mono low-level RCA and dedicated RCA LFE inputs.
Can the T/9x operate wirelessly?
Yes. It is compatible with the optional REL Arrow system, which can transmit High Level or LFE signals.
Is REL Arrow included?
No. Arrow is an optional wireless accessory and should be purchased separately.
Can Arrow transmit the low-level RCA signal?
No. Arrow provides High Level and LFE transmitter connections. The conventional low-level RCA input requires a wired interconnect.
Does the T/9x have a passive radiator?
Yes. It uses a front-firing 250mm active driver together with a matching 250mm down-firing passive radiator.
Can two T/9x subwoofers be used as a stereo pair?
Yes. One T/9x can be positioned beside each main loudspeaker, with each subwoofer independently adjusted for its channel and room position.
Can T/9x subwoofers be vertically stacked?
No. The T/9x is designed for conventional upright floor placement and is not compatible with REL line-array stacking.
Can the T/9x be used in a REL 3D home cinema system?
Yes. Its output and flexible connectivity make it suitable for selected front, centre, rear or main LFE support roles within a properly planned multi-subwoofer system.
Is an RCA interconnect included?
No. A suitable low-level or LFE RCA interconnect should be selected separately according to the source equipment and required cable route.
What finishes are available?
REL officially lists Piano Black and Gloss White. Audio T may also offer Grey or other finishes according to current UK availability.
How large and heavy is the T/9x?
It measures approximately 370 x 340 x 393mm and weighs 20.6kg. Clear operating space should be retained beneath the passive radiator.
Why Buy From Audio T?
- REL subwoofer and loudspeaker-matching advice
- Comparison with the T/5x, T/7x and T/9x Special Edition
- Comparison with the heritage-inspired REL Classic 98
- High Level amplifier-compatibility guidance
- Low-level and RCA LFE connection advice
- Combined stereo and home cinema system planning
- Single and stereo-pair setup assistance
- REL 3D home cinema planning
- Room-positioning and phase-setting guidance
- Crossover and gain setup support
- REL Arrow wireless compatibility advice
- Bassline Blue cable recommendations
- Current finish and stock availability guidance
- Ongoing system and after-sales support
Contact your local Audio T store
to discuss demonstrating, positioning and integrating the REL T/9x within your music or home cinema system.