REL T/9x SE

REVIEW
Alan Sircom
Jul 14, 2026

The standard REL T/9x SE is effectively the replacement for the T/9i we tested here. It uses the technology and product developments seen in the Serie T/7x reviewed here. It has a 10″ long-throw FibreAlloy cone with an inverted alloy centre cap in a steel chassis firing toward the listener. Additionally, there is an almost identical driver of the same size firing into the floor as a passive radiator. A 350W Class A/B amplifier powers the sub and features REL’s unique high- and low-level connections. These make it good for home cinema and hi-fi.

Ostensibly, the limited-edition T/9x Red (which became the T/9x SE) is the same subwoofer in a natty shade of gloss red at a price premium. But looks can be deceptive. It’s finished in Rosso Corsa, a specific red finish usually associated with very fast Italian cars with prancing horses in their logos. That is not an easy – or cheap – paint to work with. The result is basically a ‘blueprinted’ version of the standard cabinet built to an excessive degree. If you get it even slightly sub-par, the subwoofer gets an orange-peel finish. Then the guys in very smart suits take you on a one-way ride into the desert. Sadly, by the time the review was published, this limited-edition finish was all but gone; however, the lessons learned in making that finish permeate through the T/9x line to this day.

Super stiff

The result is a cabinet of even greater stiffness that can accommodate an even faster drive unit than the standard one. So, that main FibreAlloy cone gets an upgrade by replacing the light, inverted alloy centre cap with an even lighter carbon-fibre inverted centre cap. And lighter means faster. Much faster.

Of course, the problem with a Limited Edition model is that almost as soon as you discuss it, it’s gone. The T/9x Red is no exception. The subwoofer sold out almost immediately worldwide. While there are stocks in dealers, they are strictly limited. That invites the question, “Why review a sold-out product?” The T/9x Red proved so popular that REL developed the T/9x SE (Special Edition). This is available in a range of high-gloss colours… including ‘Italian Racing Red’. Other limited-edition models have been released, such as a bright orange one, which might also look spiffy on an Italian or German sports car.

Driver unimportant

In set-up and use, however, the colour of the cabinet and the choice of drive cover are unimportant. REL’s set-up procedure is now so well known that I feel it’s almost pointless to discuss, as you are going over a well-ploughed field. But for the uninitiated, the REL has both high-level and low-level inputs. The low-level inputs are the standard ‘point one’ subwoofer channel most commonly seen in home cinema systems. The high level is more interesting from an audio perspective. This connects to the amplifier’s loudspeaker terminals (with the speakers plugged in; you are running in parallel) via a long cable with a Neutrik connector at the REL end.

The other curious (for the uninitiated once more) part of the set-up for stereo use is just how low you set the subwoofer. You’re not watching a 1980s action movie, so don’t set the subwoofer so high that it barks along with the music. Instead, set it so that it’s only just audible, then turn it down one more notch. After a week, come back and check the settings in case something changed… You often need to turn the sub down even lower.

Magical transformation

When you do this, a magical transformation takes place, not to the subwoofer… to your loudspeakers. They sound bigger and better. The soundstage takes on a wider, deeper character, and the midrange gets more open. So far, so REL. What happens in the T9/x SE?

I’m pretty au fait with the degree of improvement the T-Serie does to systems, so I expected the same from the T/9x SE. What I got was something altogether faster, and that helped make the loudspeakers more alive further up the frequency range. This holds across the whole loudspeaker gamut. Although I can’t imagine someone with half a million quid’s worth of giant speakers adding a subwoofer at this price point, it costs less than a fuse for super-high-enders. They are missing a trick.

Speed Kings

The speed of the T/9x SE is best experienced by playing something with fast, higher-frequency transients, or transients across the board. Infected Mushroom’s ‘End of the Road’ is a perfect track to highlight when subs go right… and wrong. The sheer onslaught of attacking noises, including glass shattering and a powerful beat, can go one of two ways with a sub. It cleans up the midrange so you can hear more, or it adds ‘thump’. The T9/x SE really brings out the speed of those glass-breaking transients. Yes, you can set it to thumpy bass, but although your inner lout might approve, your outer audiophile will prefer something more musically beneficial.

In a way, the biggest downside to the REL T9/x SE is to REL rather than end users. It’s so good and so fast that it could cannibalise sales of the brand’s bigger, notionally better subwoofers. Fortunately, the bigger subwoofers also have greater sound reinforcement characteristics than the T/9x SE, Red or not. The ambience thing and the glow-up it brings to loudspeakers… that’s something the T/9x SE has absolutely nailed. But that powerful underpinning that adds rooted-in-space solidity to recordings… for that, you need a bigger subwoofer. There’s no replacement for displacement. A larger subwoofer that moves more air will deliver deeper, better-controlled bass than even the T/9x SE.

Fast enough

There is enough difference between the REL T9/x SE and other T-Series subwoofers to make this an exciting development for the company. Its faster pace makes it hard to ignore. The success of the T9/x Red begat the T/9x SE. I hope this is the first in a new line of even faster and more polished REL subwoofers. These have got all the right chops in all the right places… just like the T9/x SE.

And, if you think one is good, think what two can do… watch this space for more!