REL S/850

REL’s new Serie S marks the beginning of the company’s premium subwoofer range. The S/850 is a powered subwoofer equipped with a 12-inch driver, ABR, and an 850W Class D amplifier. The entry-level S/550 features 10-inch drivers and a 550W amplifier. Above the S/850 are the Carbon Special Black Label with an all-carbon 12-inch driver and a 900W amplifier. The top model, the 212 Black Label, has two 12-inch drivers, two ABRs, and a 1000W amplifier.

The S/850 features a shorter but deeper cabinet compared to its predecessor, the S/812. REL states this means it can be driven harder and produces substantially lower frequencies – 19Hz (±6dB) or 12Hz (±3dB). The 12-inch driver is a carbon/aluminium composite alloy with a large carbon fibre dust cap. This delivers up to 50% more output with reduced moving mass. The downward-firing ABR also features a new carbon-fibre-infused design. As a result, the S/850 can be in smaller spaces than the outgoing S/812.

High-level connections

REL recommends its subwoofers connect to the speaker output terminals of your amplifier. They supply a cable that runs from your amp’s speaker binding posts to a Neutrik Speakon input on the back of the S/850. Furthermore, they say that because of the sub’s high input impedance (150,000 ohms), it draws no power from your amp while ensuring the incoming signal to the sub is identical to that feeding your main speakers. They believe this produces better sound and helps the sub integrate more effectively.

On the back panel are controls that adjust the subwoofer’s phase relative to the main speakers, the frequency at which the subwoofer activates (between 20Hz and 120Hz), and the gain. Your retailer will set this up for you, but for those who need it, REL offers comprehensive guidance on its website. I entrusted the setup to REL’s UK sales director, Rob Hunt, who delivered the S/850 to me. It will vary for every system and room, but REL recommends placing the sub in one of the corners, behind the main speaker. In my room, this was not possible. So we positioned it in front of the left-hand speaker.

REL suggests that two subwoofers will produce a deeper soundstage and greater three-dimensionality for musicians. However, for my review, I used only one.

The bass thing

It took me a while to realise that a REL subwoofer is about much more than just the bass. Yes, it will produce deeper bass if your speakers are small, but what I discovered when I reviewed the Classic 99 for hi-fi+ in Issue 237, was that adding the subwoofer enhanced sound quality across the entire frequency spectrum. In addition, it revealed more details in cymbals, percussion, and bass lines.

Why? REL owner John Hunter explained to me that it’s because, when you let the speakers roll off below 40Hz, many fundamentals in the music and all the harmonics that derive from them are lost. This time, I was interested in hearing what would happen with the S/850 and some larger speakers than I used with the Classic 99s, namely the Fyne Audio Vintage 10, which are said to go down to 26Hz (±3dB). These were driven by my trusty Audio Note system for LP and CD. But this time I added streaming through the Metronome c/AQWO 2 (tested in Issue 248) and played Qobuz. 

I began streaming the track ‘Beautiful Fools’ from Jo Harrop’s The Path of a Tear album [Lateralize]. I noticed that with the sub enabled, the bassline’s individual beats were clearer, while her voice sounded more open, articulate, sensual, and sharply focused between the speakers. Delicate cymbal work was also cleaner. Rimshots sounded more precise, and all the different layers of the music blended more cohesively.

On to vinyl

Next was some vinyl, featuring jazz pianist and composer Fergus McCreadie. On ‘Sun Pillars’ from his Stream album [Edition], his piano sounded more open, more solid, with greater weight in the lower registers and a sharper edge when using the sub. The double bass line was heavier and easier to follow. Meanwhile, Stephen Henderson’s wonderfully delicate and nuanced drumwork was more clearly expressed. As a result, the entire track flowed better.

Next up was the title track from Joshua Redman’s latest album, Words Fall Short [Blue Note]. His soprano sax sounded better with the sub, and I could hear how he shaped each note.  It was also much cleaner in the upper registers. The bass solo was more fluid and agile. Additionally, I could listen to fingers plucking the strings. Cymbals and drums were also more delicate and detailed.

And now I come to what was the most enlightening and intriguing track – ‘We’re in This Love Together’, the title track from Chris Walker’s superb tribute album to Al Jarreau [CCW]. I had always felt that its powerful bass line was a bit overdone, but I was genuinely surprised when I switched the sub in; it cleaned it up and tightened it significantly. It was no longer overdone and became easier to follow. Was I losing my mind? I’d expected a sub to make it worse. But no, a dealer friend of mine confirmed he’d had similar experiences with REL subs. Additionally, vocals were clearer, Gerald Albright’s sax more expressive and filled with emotion, and Bob James’s piano sounded cleaner and easier to follow.

Substantial improvements

Using the S/850 in my system enhanced every element of the music. Guitar, saxophone, piano, double bass, vocals, cymbals, and percussion all sounded clearer, better defined, and easier to follow. Also, the subwoofer contributed to smoother music flow, with tighter, more focused bass lines that blended seamlessly with drums and percussion. This really made your foot tap to the beat. 

Unlike speaker cables, which differ in their tonal balance and suit various rooms and systems, a REL sub should enhance any system in fundamental musical ways. Also while it’s not about more bass… boy, can the S/850 can deliver bass. The REL S/850 is the real deal. 

Technical specifications

• Type: Subwoofer with built-in amplifier.
• Driver complement: 12in carbon alloy active driver with carbon dust cap, with downward-firing 12in carbon fibre-infused passive ABR. 
• Frequency response: -6dB at 19Hz
• Input connectors: High Level: Neutrik Speakon, low level: RCA, LFE RCA
• Amplifier: 850-watt linear Class D
• Wireless capability: Airship Direct
• Dimensions (HxWxD): 445mm x 432mm x 514mm
• Weight: 34kg
• Finishes: Piano black and gloss white
• Grilles: Black or white cloth comes as standard. Optional premium wood grille £449 extra
• Price: £3,599

Manufacturer

REL Acoustics Ltd

rel.net

+44(0)1656 768777

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