The REL T/x Series at a Glance
The T/x series is REL Acoustics' entry into serious audiophile subwoofing, and it embodies everything the British specialist is known for. These are not generic subwoofers bolted onto a system as an afterthought. They are sub-bass systems engineered to integrate seamlessly with your full-range speakers, disappearing into the soundstage while adding the weight, air, and dimensionality that your main speakers cannot produce on their own.
What sets the entire T/x range apart, and REL as a whole, is the signature High Level connection. Using a Neutrik Speakon cable taken directly from your power amplifier's speaker terminals, each T/x sub receives the same amplified signal and tonal character as your main speakers. This is the heart of REL's approach to music, and it is why these subs blend so convincingly on two channel material. Every model in this guide also offers a Low Level RCA input and a dedicated .1/LFE input, so the same subwoofer serves double duty for home theater bass management when you want it to.
Shared Design Language Across the Range
Every T/x subwoofer shares fast, musical, filter-less voicing, continuously variable crossover and gain controls, and a phase switch to time align the sub with your room. All four are offered in high gloss finishes, all accept the three input types described above, and all are wireless ready with an optional REL wireless system such as the Arrow compatible transmitter, so you can avoid a long wired run when placement demands it. Always confirm the specific wireless system that matches the model you choose, since a transmitter makes no sound on its own and must be paired to a compatible subwoofer.
The Models, Tier by Tier
Entry Tier: REL T/5x
The REL T/5x is the compact starting point of the series. It uses an 8 inch long-throw forward-firing driver in an active closed-box cabinet driven by a 125 watt Class D amplifier, reaching down to 32Hz in room. Its footprint is genuinely small, at roughly 300 x 260 x 314 mm and about 27 pounds, which makes it ideal for tight rooms, apartments, and desktop-adjacent or bookshelf systems where a larger sub simply will not fit.
The T/5x is the natural partner for smaller standmount and bookshelf speakers, and for listeners who want to add genuine REL integration and musicality without dominating the room. It pairs beautifully with compact two channel setups and modest home theater rooms alike.
Mid Tier: REL T/7x
The REL T/7x steps up to an 8 inch forward-firing active driver augmented by a 10 inch down-firing passive radiator, now driven by a 200 watt Class A/B amplifier. Extension deepens to 30Hz, and the added radiator gives the T/7x a fuller, more effortless bottom end. This is one of the most popular RELs for good reason. It offers a generous balance of output, extension, and refinement in a cabinet that still suits most rooms.
The T/7x is the sweet spot for medium sized rooms and for floorstanding or larger standmount speakers. If you want a sub that handles music with finesse and still delivers convincing weight during films, this model rewards the step up. It is also compatible with the broadest set of wireless options in the range, including Arrow, AirShip II, and HT-Air MKII.
Upper Tier: REL T/9x and T/9x SE
At the top of the series, the REL T/9x moves to a 10 inch long-throw forward-firing active driver paired with a 12 inch down-firing passive radiator, powered by a 300 watt Class A/B amplifier. Low frequency extension reaches 27Hz, and the larger driver and radiator combination produces more output and a more authoritative foundation than the models below it. This is the T/x model for larger rooms and larger speakers, and for listeners who want the deepest, most confident bass the series can deliver.
The REL T/9x SE is a special edition refinement of the T/9x concept. It retains the 10 inch long-throw forward-firing active driver and the 300 watt Class A/B amplifier with 27Hz extension, paired here with a 10 inch down-firing passive radiator and finished in high gloss lacquer. The SE is aimed at the listener who wants the top of the T/x ladder with an added measure of finish and voicing refinement.
Which REL T/x Should You Buy?
By Speaker Size
For compact standmount and bookshelf speakers, the T/5x matches naturally and integrates without overwhelming them. For midsize standmounts and moderate floorstanders, the T/7x is the balanced choice. For larger floorstanders and full range speakers, the T/9x or T/9x SE supply the extra output and extension those speakers deserve.
By Room Size
Small rooms and apartments favor the T/5x. Medium rooms are well served by the T/7x. Larger listening rooms and dedicated spaces call for the T/9x or T/9x SE, which have the driver area and amplifier headroom to properly pressurize the volume.
By Music Versus Home Theater
Because every T/x sub carries REL's High Level connection, all four excel at music integration for two channel listening. If music is your priority in a modest system, the T/5x and T/7x deliver that signature seamless blend beautifully. If you want cinematic slam alongside musical finesse in a larger room, step up to the T/9x or T/9x SE, whose greater output and lower extension bring more impact to film soundtracks through the .1/LFE input. Listeners chasing the very last measure of refinement at the top of the series will gravitate to the T/9x SE.
A Note on Going Bigger with Two
If you find yourself between models or want to future-proof, remember that two RELs can be stacked in a line array for greater output and a larger, more enveloping soundstage. Two matched T/x subwoofers often integrate more evenly across a room than a single larger sub, so it is worth discussing if your goals are ambitious.
Let Us Help You Match a REL
All Elite Audio is an authorized REL Acoustics dealer with a showroom in Timonium, Maryland. Demo units rotate and not every model is always set up, so we invite you to contact us to arrange a listen or to help match the right REL T/x subwoofer to your speakers and room. Whether you are building around compact standmounts or driving a large room with full range towers, we are glad to guide you to the model that will disappear into your system and simply make the music sound whole.