Smaller does not mean lesser. We designed the compact T/5i to give smaller sized spaces and systems equal quality sound, so while scale may change the performance stays the same.

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Purity Reimagined

Stunningly Simple

Simplify, Then Add Lightness: Simplicity is its own reward and T/5i reduces the classic cubic sub to its bare essence. A single, high quality AlloyFibre™ composite driver and down firing orientation produces maximum coupling with the floor and eliminates the need for a grille. T/5i is the purest expression of REL.


Reinforced Simplicity

A 360-degree Upgrade

When we upgraded our drivers, we were forced to redesign outward. The lovely cabinets grew over its predecessor due to thicker cabinet walls and improved bracing. Why? Because the additional speed and impact of the new drivers requires greater control or the benefits can be lost before they get to the listener.


Faster & Deeper


We began by updating our classic 8” bass engine to reduce mass, while greatly increasing stiffness. This improvement led to upgrading cabinet dimensions and wall thickness to better control the deep bass. Additional upgrades extended even into the design of our feet, resulting in greater speed and solidity to the presentation of sound.


Proven Power

REL's Reliable Brains And Brawn

REL’s electronics are the brains and power behind our success. Serie Ti uses the same Class A/B power amplifier sections with large, high current power supplies, precision-wound transformers and an amazing reliability record that has powered some 100,000 RELs. Standby Mode switch not included on 110V units.


Zero Compression Wireless

Introducing Arrow™

Arrow™ is REL’s latest generation of zero compression wireless. Super-fast delivery of both High Level Bass and .1/ LFE ensures the rich, natural warmth that only RELs can deliver. With a throw distance of some 45’(13.7M) Arrow permits flexible placement without sacrificing sound quality.

Customer Reviews

Based on 33 reviews
Best Blend

After trying a few other (lower priced) subwoofers, I brought this REL home and found the perfect match in my listening space with Triangle Titus. The 5i is just what the Triangles need. Together, this is a set that sounds, to me, as the most live-like reproduction possible in this price range. The crossover on the REL needed to be set higher than the suggested starting point, but that's one of the beauties of the REL -- it's flexibility. An added bonus is the high-end finish on the REL (white) is a perfect match to the white gloss on the Triangles.

Spendor s3 with t5i

I love my new t5i sub. It does exactly what I hoped it would - gives my spendors improved tonal balance and expansiveness. Now I’m hearing the bass, rather than imagining it, and this makes my experience of the whole sound much more complete and enjoyable. There’s also more spatial information.

T/i5 paired with Chorus 714 speakers

Very please, use with tube integrated, which seems to be lacking in low end, fills in what now seems to have been missing with the 714's, blends in very very well, T/i5 holds up it's end of the job without trying to over take the 714's


I ordered this sub after my disappointment with the Martin Logan. I was watching Paul of PS Audio's YOUTUBE video., and he mentioned that a sub will enhance the sound of my hi-fi system which I thought already sounded very good to my ears. And he specifically an REL subwoofer. He was dead on! I was pleasantly surprised because I now hear and feel the lows that I never had before. And when I play my meditation and spiritual enlightenment background music, I feel the sound envelope my whole body. I am truly impressed and I plan to buy another in the very near future.

Very Musical Sub

The Rel T/5i has proven to be an excellent companion to a pair of Kef LS50s in my small (11ft X 12ft) listening space. Integration with the supplied High Level Speakon cable is seamless and fills in the bottom end (bass) with noticeable improvements in soundstaging and scale. Impressive build quality and precision feel of the controls are an added plus.


Suggested Retail: $599

Smaller does not mean lesser. We designed the compact T/5i to give smaller sized spaces and systems equal quality sound, so while scale may change the performance stays the same.



Closed Box, down-firing driver

Active Driver Size & Material

8 in., 200mm long-throw, FibreAlloy™ inverted aluminium dust cap, steel chassis, white cone

Passive Radiator Size & Material


Low Frequency Extention

-6dB at 32 Hz

Input Connectors

High Level Neutrik Speakon, Low Level single RCA, LFE RCA

Output Connectors


Power Output

125 watts (RMS)

Amplifier Type

Class A/B

Wireless Capability

Arrow (Optional), Zero Compression, Single Large Scale Integrated Chip

Protection System

Fully Electronic Set Safe


D.C. Fault


Output Short


Mains Input Voltage

220-240 volts, 110-120 volts for certain markets


1.6 Amp semi delay 230 volts operation, 3.15 Amp semi delay 115 volts operation


W x H x D

10.5 x 12.5 x 12.7 in. (267 x 317 x 322 mm)

Net Weight

26.5 lbs. (12 kg)


High Gloss Black, High Gloss White, 5 coats

Supplied Accessories

Mains Lead


Neutrik Speakon

Yes (10 Meters Nominal)


Users Manual


In the interest of product development, REL Acoustics Limited reserve the right to vary these specifications without notice.