Syzygy SLF-850 Subwoofer

The dictionary says that Syzygy is pronounced siz-i-jee, with the emphasis on the first syllable. A syzygy is defined as an alignment of three or more celestial objects.

Listening to the heavy bass groove in George Michael’s Older, I couldn’t agree more. My Quad 2815s and a pair of the SLF850 subwoofers are blending perfectly; this is not an easy task for any subwoofer. They don’t even feel as if they are on to begin with until the “mute” button on the handy iPhone app shuts them off. Then, the soundfield produced by the Quads merely collapses. This is subwoofer perfection.

Finished in a textured, matte black 12.5-inch cube, these subwoofers get the job done without drawing attention to themselves and can be used in a downward or front-firing configuration. In my room they prove to work best in the front firing configuration, but I have no pups of the two or four-legged variety to interfere with all things audio. Should you, the down-firing option will be greatly appreciated.

The main man at Syzygy, Paul Egan is by no means a stranger to the world of high-end audio, having spent 13 years at KEF and nearly as many at API, working with Mirage and a few other well-known speaker brands. So, when the time came to create his product, he not only knew what he wanted but where to procure everything. Leveraging his past relationships, he’s been able to pack a lot more into a sub-thousand dollar subwoofer than someone starting at ground zero. Keeping things lean and mean, he’s even eschewed putting grilles on his subs to keep them all business. Discussing the background of his products, Egan makes an excellent point when he says “I’m trying to democratize good sound at a reasonable price.” At $799 each, the SLF850 is a steal.


While there are two other 8-inch subs and a 12-inch in the product mix in addition to the SLF-850 reviewed here with a 10-inch carbon fiber driver, all but the smallest model are acoustic suspension with full wireless capability. While one sub is better than none, if you’re trying to extend the LF response of your speakers, a single sub can take a little more effort to place.

Which is why I enjoy wireless subwoofers so much. No worrying about running long cables to the proper placement. The DSP optimization functionality of the SLF850 takes this a step further, because the EQ makes it easy to place and integrate the woofer. Should you want to use your SLF-850 in a traditional, wired configuration, supplying signal from either your surround sound receiver’s LFE channel or the high level outputs from your preamplifier, that is no problem.

Setup couldn’t be more painless. These compact cubes unpack quickly and Syzygy includes an excellent manual to get you rocking in no time at all. If you are proceeding in wireless mode, the tiny Bluetooth receiver/interface needs to be plugged into a variable line-level output with traditional RCA cables. Once the SLF-850 is placed where you need to put it, download the app on whatever device (iPhone or Android) you possess and run a few processes.

First, the Syzygy Sub app finds and measures your woofer(s), with your smart device about a foot from its output. Then, moving to your listening position and running another sweep adjusts the woofer to your listening environment for optimum bass performance right at the sweet spot with the “Auto EQ” function.

This will get you about 90-95% of the way home and a bit more fine tuning will bring it all to perfection. Depending on the type of main speakers you are using, the Low Pass feature allows adjustment of the crossover from 40 – 150hz.

After everything is adjusted to taste, you can control the output level from your phone, and choose “normal,” “music,” “cinema,” or “night” settings, which are more like a preset bass level control. As I don’t have neighbors close by anymore, I just let the SLF850s rip in normal mode with excellent result, regardless of program material. The mute button helps you fine tune, making it easy to cut the woofer(s) out of the loop. The better you have it all dialed in, the less you notice the woofers, until a deep bass passage – as it should be.

A versatile performer

Though Egan sent me a pair of SLF850s for this review, I started with one, because not everyone will jump off the cliff for a pair right off the bat. Three sets of speakers were used, all presenting different perspectives. My Graham LS5/9 speakers go solidly down to about 40hz, with useable output to 30, making them a good speaker that can be run full range. The KEF LS-50s are strictly a satellite, being a challenge for any subwoofer because it will have to go sufficiently high without coloration to mate well with the little monitors. Lastly, the Quad 2812s are equally tough, but for different reasons; the difference in dispersion characteristics of the ESL panel and a piston woofer (not to mention the lightning speed of the ESL panel) is usually near impossible to get right, where you aren’t hearing speakers here and woofers there. But it can be done.

The short story is that the SLF850, both singly and as a pair mates flawlessly to all three of these combinations. In single woofer mode, the SLF850 was placed just slightly off center of the main speakers (all three) back against the rear wall in front firing mode. Thanks to the fine tuning allowed by the app, there were no issues at all integrating the SLF850 into the system and for the most part, if I were in a smaller space, I could probably get along just fine with one woofer.

Moving to dual woofer mode, the little KEFs worked great with the SLF850s slightly behind and off to the side of the stands. The Grahams a bit further in both directions and with the Quads, I ended up with the woofers fairly far back, almost behind the listening couch. This made for the most seamless integration. Not only did I notice even better integration, but a pair provides wider dynamic range and better low-level linearity as well. The bulk of the listening sessions were with two woofers in place.

You don’t realize you need it till you have it

If you’ve been predisposed to thinking that you don’t need low-frequency extension, prepare to be surprised. Even with the LS5/9s, which I previously thought had plenty of bass in my 11 x 18-foot listening room, came alive with a pair of SLF850s added to the mix.

They certainly made for a lot more fun with my favorite Dubstep and hip-hop tracks as well as the entire Genesis catalog, yet even when playing music that you might not think has a ton of LF content, the soundstage in the room opens up considerably with the woofers in place. Tracking through the classic Roberta Flack & Donny Hathaway hit, “Where is the Love?” the pair of SLF850s gives both singers voices more depth and breath. Ditto listening to Miles Davis’ Tutu. Yes, the heartbeat at the beginning of Dark Side of the Moon was pretty rocking too. Again, just hit that mute button to see what you are missing.

The LS-50s took the longest to optimize (about 15 min as opposed to about 5 min with the other two), but again, once the sweet spot was located, things jelled tremendously, and these small but mighty monitors could now light up the room with heavy rock music and play considerably louder too.

Skeptical as I was that these speakers would not be able to keep pace with the Quads, (and Egan assured me that they would) they succeed brilliantly with these pesky panels. The current crop of Quads is much livelier than models past, but they are still Quads. You won’t get much enjoyment out of Metallica without the woofers, yet once in place, hard rock can now be appreciated. Grooving through TIDAL’s “favorite dance tracks of 2016” proved equally entertaining. With some serious bass happening, I’ve been able to enjoy the Quads like never before. Purists be damned.

56 pounds of sheer fun

That is if you take two. But regardless of whether you add one or two of the SLF850s to your system, fine tuned, low-frequency extension is easy and affordable. Thanks to the wireless, DSP configuration and the small form factor, I can’t think of anyone not being able to integrate at least one of these into your listening room. You’ll be glad you did. I’m adding the review samples to my Audiophile Apartment system, so you’ll be seeing and hearing more of them in reviews to come.

Our compliments to Paul Egan and the staff at Syzygy for delivering an outstanding product at a very approachable price; earning them one of our first Exceptional Value Awards for 2017.

The Syzygy SLF850 Subwoofer



Amplification        Esoteric F-07 Integrated, PrimaLuna HP Integrated

Analog Source     Soulines Kubrick Turntable/ZYX 1000 cartridge

Digital Source        Gryphon Kalliope DAC, ELAC DS-101G Server

Speakers        KEF LS-50, Graham LS5/9, Quad 2812

Cable            Cardas Iridium