Serie S


S/812 takes REL’s medium chassis concept to reference-like levels of performance and does so with style, beauty and devastating power. It delivers incredible levels of all ‘round performance for both music and film sound, gives customers a taste of what our reference models offer, and does so at a fraction of the cost.

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The All New S/812

Shattering Performance Barriers

For S/812, every aspect of the previous generation’s inner workings were examined without regard to its critical and customer-driven success. We turned a fresh eye to power requirements, driver improvements, and specialty filters, upgrading each to extract all the extra performance possible. All this alongside the cabinet refinements necessary for those upgrades to emerge cleanly. This latest S range is a triumphant development that has exceeded every expectation of our design team.

Our requirements were for far stronger deep bass output between 19-35 Hz, vastly improved theatre dynamics, and an even more open and spacious soundfield which benefits both music and film. We turned to our NextGen5 amplifier, tuned to 800 watts, with huge reserves of power beyond this, added a light film of carbon fibre to the rear of the driver to handle the extra power, and developed two new sets of custom filters to extract the utmost in brute force and spaciousness. Finally, we imbued 812 with the ability to be stacked in 4- or 6-unit line arrays, just like our reference models.


Invisible Upgrades to S/812’s Bass Engine

Pure Carbon Fiber Backing

S/812 required upgrades to its ContinuousCast™ Alloy Cone to allow it to survive the massive power upgrades. To permit its thin, aluminum cone to survive 800 watts and incredibly long stroke, we added an ultra-lightweight backing of pure carbon fibre, strategically placed over portions of the rear surface of the cone. This produces two benefits; it strengthens and stiffens the cone and also eliminates reversion, wherein the backwave inside the cabinet is now prevented from interfering with the main launch of bass into the room. The result is more accurate and far louder deep bass.


There is Nothing Passive About These

Carbon Passive Radiator

Our uniquely tuned passive radiators use special suspensions, now with an additional 30mm of linear travel, to produce performance far beyond conventional subwoofers. Our new SuperProgressive™ passive radiator produces extremely long travel allowing for very loud output while retaining the variable stiffness of its suspension. This allows it to act like a sealed box compact 12” design at low volume and a high output 14” design at its limit.


Warning: Power Amplifier on Steroids

800 watts and Counting

At 800 watts the NextGen5 amplifier is borrowed from our reference models and rocks huge reservoirs of power and current. The 45% increase in power (previous version was 500 watts) is needed to deliver both the profound output levels needed for modern theatre, as well as to produce the deepest bass in a high end 2-channel system. This increase in power is necessitated by our development on the musical front of an all-new circuit termed PerfectFilter™ that balance both frequency extremes.

PerfectFilter performs two seemingly disparate qualities; extending the strong, even response of the extreme low end of bass frequencies while simultaneously opening up air and delicacy in the middle and high frequencies of one’s system. Additionally, we applied customized PureTheatre™ filters to allow S/812 to deliver the most awe-inspiring theatre effects ever offered in a classic REL.


Serie S Line Array

Stacked for Ultimate Performance

In the real world, bass occurs with width, depth and height. By stacking up to three units per side (stereo or theatre main L-R speakers) the proper perspective and height of sonic events are illuminated. This elevates reproduction from conventional stereo or theatre to a floor-to-ceiling panoramic, full scale perspective of each sonic event. Reviewers are lining up to marvel at the transformation of music and film into the full-scale representation that REL Line Arrays uniquely deliver.

Customer Reviews

Based on 12 reviews
What an upgrade, and what an amazing company!

My speaker system consisted of the Totem Model One Signatures and a Linn AV5150 subwoofer. The Linn is an amazing subwoofer and served Me well for over 15 years. However, I felt it was time for an upgrade, and the wireless option offered with the S/812 sounded quite appealing. I contacted My dealer Connon from Tune HiFi here in Seattle and he bought the S/812 over for an audition. He set it up and connected it via the REL Airship wireless connectivity kit, and then left Me to My own devices. It’s a challenge to explain (without listening to one) how a well-engineered subwoofer while producing amazing deep and tight bass, provides additional support to the midrange. The air that I can hear around voices, and hearing fingers slide across guitar strings is nothing short of breathtaking. Then there is the soundstage… I feel transported to a cave, a church, or an auditorium, depending on the recording. And then there was Godzilla verses Kong…. The experience of feeling two titans throw down and shaking My living room was nothing short of awesome!
Unfortunately, the S/812 started to develop intermittent thumps without music playing, and I could not figure out why. I tried different interconnects, and re-pairing the Airship to no avail. I connected Connon and found out the he had unexpectedly lost his mother. Needless to say, he had more important matters (We only have one mother) to attend to than My subwoofer issue, so after offering My condolences, I contacted REL and asked them could they do some sort of work-around, as I wanted to give Connon all the time he needed to attend to the loss of his mother.
Christopher and Rachel at REL were more than understanding and respectful of Connon’s situation and worked with Me directly. After describing My issue, they determined it was most likely the Airship that wasn’t functioning properly, and promptly issued Me a replacement unit along with an RMA label to ship the other unit back to them. After the unit arrived, I installed it and there hasn’t been anymore issues.
Additionally, they passed on their condolences to Connon, as well as a message stating that if he needed anything, to simply call them, and they would be happy to help. If you want to buy a product that is of exceptional build quality, and have the support of a company the that treats its staff, dealers, and customers like family, consider giving REL the opportunity to serve you.

Curtis Huffman

I bought one from Up Scale audio; got it home; hooked it up....loved it....SO, i purchases a 2nd one from Up Scale....WOW, now I have my own bass section, or so it would seem. I am running all tube equipment (Prima Luna gear) and these two subs are augmenting my Klipsch Hersey 3's until i can get corner horns....but these subs add what i have been missing all my life.....just the right amount of bass.....i am not an audiophile nor do i have the greatest gear in the world....but I am sure I am getting $100K sound out of my $40K system....and the REL's bring it all home....these babies are not even broken in yet....hope to have them broke in so when i get the Khorns, my life long dream of having "the sytem" in my mind, anyways...is done.....great investment.

Cedric Hubeau
Easy setup and clear upgrade

I purchased a single S/812 at the end of 2020, as suggested by the subwoofer finder/speaker pairing. It's a lovely-looking piece of kit that screams outstanding fit-and-finish. I love the high level input that ensures that the S/812 blends perfectly with my speakers since I use it mostly for music. I upgraded to the Bassline Blue cable, which brought a subtle yet noticeable improvement over the standard cable in terms of naturalness. Placement and gain/crossover tweaks took few weeks. Counterintuitively, the S/812 works better when placed on the inside of the right speaker, halfway between said speaker and my equipment rack, aimed at the listener/seat. I settled with the gain one click over 9 o'clock, and the crossover about one click over 10 o'clock. Yes, some tracks can use a higher crossover or gain, but this particular setup works across all tracks in a long listening session. I listen to a lot of music across various genres. The S/812 has added depth and scale to many tracks, with more texture on voices and the midrange in general. And of course, segments with very low range (organ, synth, various drums, electric bass or double-bass) have become much more impressive without sounding overblown. Interestingly, this applies to recordings that used to sound "thin" including few piano albums that now sound fuller (but again, not artificially so). Very pleased.

Yves Normand

The S-812 has an excellent quality, after breaking in as recommended on the web-site.
The only complain I would have is the following:

I understand and agree that Rel builds very high quality sub-woofers. I watched many video from John Hunter and do trust his engineering and expertise. Very impressive guy!!!

However, as far as packaging, there should be more dedicated engineering on this aspect, PLEASE COMMUNICATE THIS EMAIL TO MR HUNTER...
Packaging seems weak and not be adequate for such units. I own several McIntosh equipment and was impressed with their packaging…

After the package was delivered and left at my door (too late to complain), I found after unpacking that one of the vertical side edges got busted (by some lift?). The cardboard had a large cut on each vertical side for about 4 or 5 inches.
It seems that the vertical side edges are not protected at all. The top and bottom were indeed solid, vertical side edges had no protection. See attached picture.

Some to think in the future with your development Team and Mr. Hunter. It is unfortunate for me, such a beautiful unit. And… this was my second unit ordered this month.

More Than Richness

My wife was outraged when I said I'd like to try a subwoofer with my system. She pointed out that I already had an excellent system with deep bass (down to 32hz). What more could I want? Why would I want to mess up our living room with a box that sticks out like a sore thumb? So just to see what would happen, I assembled a cardboard box with the exact dimensions as the S/812 and placed it behind the TV stand where the subwoofer would go. After several days, she hadn't noticed it. It was invisible. The actual unit itself, being black, is even more invisible.

So having gained provisional approval, I went ahead and ordered the sub. After a week or so of fine tuning, I got it to the point of "disappearing" sonically. It's there without drawing attention to itself. So just a few minutes ago I put on a meditative jazz piece by Gerry Mulligan—Night Lights. There are no drum thwacks on this piece. Nothing that would qualify as a sonic spectacular. It's simply mellow jazz with a single upright bass providing the foundational notes. When the CD ended I played a track with the sub disconnected. Here's my wife's response: "With the subwoofer on the music is so much richer. Actually richness doesn't quite express it. As you know, my dad was a saxophone player. Occasionally I would go to his club performances. Every so often he would look up at me as he was playing and I'd feel a special flutter in my stomach. That's the feeling the subwoofer brings to the music."

Her response is what I believe REL intends. It's not about precise measurements. It's not about "pumping up," boosting, or intensifying. It's about letting the music reveal itself intimately and fully.

[P. S. My wife just apologized to me about having gotten so infuriated about the subwoofer.]

Reviews + Awards

"The REL S/812 is a genuinely impressive subwoofer that manages to combine low-end extension with powerful amplification to produce a performance that’s responsive, controlled and highly effective. This sub goes deep and, even on its own, had absolutely no trouble filling my home cinema with low frequency energy. However, this is no blunt instrument, and the S/812 is capable of astonishing deep bass that’s delivered with a surprising amount of subtlety and grace."

AV Forums

"A friendly warning: A pair of S/812 changes the personality, the emotional output, of a system. Further, to a substantial degree it changes your relationship with familiar recordings. And prepare to feel a little deflated when you remove it from the system. It’s like air being released from a balloon"

The Absolute Sound
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Suggested Retail: $2,999

S/812 takes REL’s medium chassis concept to reference-like levels of performance and does so with style, beauty and devastating power. It delivers incredible levels of all ‘round performance for both music and film sound, gives customers a taste of what our reference models offer, and does so at a fraction of the cost.



Front-firing active driver, down-firing passive

Active Driver Size & Material

12 in., 300mm long-throw, Continuous CastAlloy™ cone structure, cast chassis

Passive Radiator Size & Material

12 in., 300mm Carbon/Carbon flat cone structure, steel chassis

Low Frequency Extention

-6dB at 19 Hz

Input Connectors

High Level Neutrik Speakon, Low Level stereo RCA, LFE RCA, LFE XLR

Output Connectors

High Level Neutrik Speakon, LFE RCA, LFE XLR

Power Output

800 watts (RMS)

Amplifier Type

NextGen5 Class D

Wireless Capability

Yes- REL AirShip system [required]. Sold separately.

Protection System

Fully Electronic Set Safe


D.C. Fault


Output Short


Mains Input Voltage

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


5 Amp 220 volts operation, 9 Amp 120 volts operation


W x H x D

17.5 x 18 x 20 in. (430 x 455 x 514 mm)

Net Weight

75 lbs. (34 kg)


Piano Black Lacquer, White Lacquer, 8 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.