Reviewers' ChoiceDiscontinued well over a decade ago, Synergistic Research’s quantum tunneled X-series cables ran with the best in terms of soundstaging, three-dimensional imaging, transparency, speed, leading-edge detail, noise reduction, and dynamics. However, as I wrote at the time, those cables could sound a bit harsh and grainy in the upper frequencies. And given the great amounts of detail they could convey, and their somewhat forward sound, they could be fatiguing in some systems.

These observations are not criticisms. While there were cables out there that bettered the X models’ midrange bloom and harmonic texture, few, if any, could run head-to-head with them where they were strongest. Clearly, Ted Denney, Synergistic’s founder and lead designer, was on to something.

Over the next few years, Denney steadily improved Synergistic’s cable designs, using increasingly complex geometries and conductors made of such exotic materials as tungsten and graphene. The effects of these changes -- which, among other things, improved the cables’ harmonic richness -- elevated them to world class. Still, Denney’s continuing challenge was to preserve his cables’ exciting, dynamic, detailed sound, while putting even more meat on their sonic bones.

In 2013, Synergistic developed its proprietary Uniform Energy Field (UEF) electrical filtering compound, which further improved on the characteristics for which the company’s cables were already known, including noise rejection and perceived frequency response. Yet the compound also caused the cables to sound more effortless, rounded, full-bodied, and harmonically dense. Indeed, more than a few, me included, thought that Synergistic’s Galileo UEF cables (discontinued) represented the state of the art of audio cables. Seeming to yield nothing sonically, they engaged me on numerous fronts as no cable had done before.

In 2017, Synergistic introduced a very complex, limited-edition power cord, the SR25 ($20,000 USD). Delivering not only juice but also extensive electrical filtration, the SR25’s active geometry centers around 16 round, flat-mesh conductors of pure silver and copper that operate as a large, grounded, multi-layered electromagnetic AC filtering cell. Within that cell, two smaller cells provide targeted filtering of the current’s hot and neutral legs. And that just scratches the surface of the SR25’s features.

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Some of the SR25’s technologies have since appeared in other Synergistic products, including the subjects of this review, the Galileo SX models, which replace the Galileo UEFs: the Galileo SX interconnect ($7500/1m pair, RCA; $9500/1m pair, XLR), the Galileo SX speaker cable ($17,500/8’ pair), and the Galileo SX Integrated Frequency Termination (IFT) jumpers ($2000/pair).

In light of the Galileo UEFs’ extraordinary performance and the new technologies Synergistic claims to have baked into the Galileo SXes -- some developed for the SR25, some new -- I was eager to get the new cables in house.

“Without a filter, a man is just chaos walking.”
-- Patrick Ness, Chaos Walking

The Galileo SXes’ complex, non-active geometries share much with those of the Galileo UEFs. Anyone interested in the Galileo SXes should read my review of the Galileo UEF cables. Briefly, like the UEFs, the Galileo SXes are hand-built in Synergistic’s factory in Santa Ana, California. Each features multiple parallel conductors, monofilament and multi-axial, of 99.9999%-pure silver, tungsten, and graphene -- ten conductors in each speaker cable, four in each RCA interconnect, and six in each XLR interconnect. The conductors are surrounded by dielectrics of air, Teflon, and silk, as well as conductive shields that not only repel electromagnetic and radio-frequency interference (EMI and RFI, respectively), but also direct static electricity and high-frequency noise to ground.

Fitted over each of the Galileo SX cable’s exterior is a large, cylindrical, inductive AC filtration cell clad in carbon fiber that is not part of the signal path. Each cell is a labyrinth of sophisticated electrical engineering containing foil layers of 99.9999%-pure silver, copper, graphene, and UEF compound, all surrounded by a dielectric of Teflon and Japanese silk.

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The UEF compound is not only in the filtering cells but is also strategically positioned throughout the Galileo SXes, including on their shields, the latter also containing graphene. Further, each cable’s conductive parts are treated with Synergistic’s quantum tunneling conditioning process. Thankfully, this isn’t the quantum-barrier penetration that occurs during nuclear fusion. Ted Denney says that it involves enhancing the parts’ ability to conduct signals by subjecting them to a high-frequency signal at 1 million volts.

The Galileo SX cables also feature custom-designed silver connectors, removable passive SX sound-tuning “bullets” that attach to the cables’ shields with barrel connectors, and, for the interconnects, a star-grounding mechanism that permits their shields to be connected to an AC wall outlet’s ground pole via an included ground cable. For enhanced performance, the interconnects can be connected to one of Synergistic’s Ground Blocks ($595 to $2995).

The Galileo SX Integrated Frequency Termination (IFT) jumper cables’ geometries are identical to those of the thin pigtails that split off the SX speaker cables and connect to the speakers’ binding posts. The jumpers’ design eschews a shotgun biwiring approach in favor of one in which the signal runs from the power amp through one cable, and is then split just before the speaker terminals. Denney states that these jumpers exhibit extremely low phase distortion.

As with the UEF cables, Denney recommends that the Galileo SXes be used with one of Synergistic’s ultra-low-radio-frequency (RF) wave generators, such as the FEQ X4 ($995) or the 52”-tall, iPad-controlled Atmosphere Infinity ($3495). He states that these products excite the UEF filtering compound, in the SX cables, thus increasing their performance.

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The Galileo SXes bring to the cookout five principal design changes from earlier Synergistic cables:

1) An improved version of the UEF compound. Synergistic is tightlipped about the compound’s details, but says that this new variant, developed for their Blue fuses, further increases performance, and has a shorter and more linear break-in period than the original.

2) The shield’s construction features a new matrix grid pattern that was selected after six months of double-blind listening tests. This new design, trickled down from the SR25 power cord and not used in Synergistic’s less expensive lines of cables, is claimed to reduce ringing, and thus distortion.

3) An improved quantum tunneling treatment that uses a new high-frequency sweep pattern claimed to further improve performance.

4) Also trickled down from the SR25 cord are the Galileo SX tuning bullets, two of which -- one colored gold, one silver -- are provided for each cable channel. As in the Galileo UEF cables, the gold bullet is claimed to emphasize body, warmth, and musicality, the silver to emphasize speed, detail, and leading edges. According to Denney, the SX gold bullets are faster, more detailed, and cleaner on leading edges, while the SX silver bullets are more full-bodied, warm, and musical than their UEF counterparts.

The gold and silver bullets are included with the Galileo SX cables but are also sold separately ($300/pair). They can be used to improve the sound quality of Synergistic’s lower-priced Atmosphere X cables and many of the company’s older cable lines, including the Galileo UEFs. Just swap out those cables’ old bullets for the new.

5) The Galileo SX speaker cable and IFT jumper don’t include star grounding, though the Galileo SX interconnect does. Denney told me that while the sounds of some systems benefited when the Galileo UEF speaker and jumper cable were star grounded, most suffered -- so he omitted the feature for those models.

“The conversation of bullets.”
-- Markus Zusak, The Book Thief

My complex stereo system requires five pairs of interconnects. This is because, in addition to the usual two-channel components, I use, at line level, two JL Audio Fathom f113v2 subwoofers; JLA’s CR-1 active subwoofer crossover; and YG Acoustics Kipod II Signature speakers, whose powered bass cabinets connect to the CR-1.

To further complicate things, the CR-1 is so positioned that its rear panel is difficult to access. If you think that’s a dumb setup for someone who reviews lots of cables, join the club. Throw in the fact that the Galileo SX speaker cables are thick and stiff (the interconnects are less so), and installing these cables promised to be a challenge.

I requested review samples of four pairs of Galileo SX interconnects terminated with XLR plugs, and one pair with RCA plugs, the latter because the CR-1 has only single pairs of (XLR) and single-ended (RCA) amplifier output jacks. I requested spade connectors for the Galileo SX speaker cables. Unlike bananas, spades don’t tend to break when stressed.

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Aside from some painful arm contortions, connecting the SX cables went smoothly. Also in the plus column was that the cables had already been burned in by Synergistic. Although I was thus unable to test Denney’s claims regarding break-in, it was a trade-off I was willing to make to avoid having to do it myself.

Synergistic’s many products, including its cables, power cords, and bowl-shaped MIG 2.0 component footers, typically offer multiple setup options, each of which alters the sound in different ways. In short, their products can be “tuned” to match the stereo system in which they’re used, and the listener’s taste. The Galileo SX cables, for example, offer the configurable tuning bullets. Further, the MIG footers, which I use in my system, can be positioned with their rounded sides up or down. Each position produces a different type of sound: warm and layered, or focused and impactful.

After I installed the Galileo SX cables in my system, Ted Denney arrived to ensure that they were properly dialed-in. They weren’t. Because I knew that Denney was coming, I’d lazily left everything as it was when the Galileo UEF cables were in the system.

Denney began by selecting two or three recordings that we then repeatedly played during setup. He then removed the tuning bullets from each SX cable and my Synergistic power cords, which also use bullets. Starting with the source component’s interconnects and working his way through my system to the speaker cables, Denney auditioned each cable with both the silver and gold bullets, each time selecting the one that sounded better to him. The differences in sound between bullets ranged from the subtle to the profound. But there was always a difference.

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Denney soon turned the task of choosing bullets over to me, stating that he’d reached the point where he was tuning the system to my taste. Next, we repeated the above process with the Synergistic power cords and then the MIGs, each time beginning with the source component.

In short, Synergistic’s cables can’t be haphazardly thrown into a system. For example, Denney states that virtually no system will sound best with all gold or all silver bullets. However, as discussed below, these cables will not only pay huge dividends for those willing to put in a little effort, but will greatly increase the chances of or even guarantee that the cables will sonically match a system’s sound or the owner’s personal taste.

I listened to the Galileo SX cables with and without the Ground Block and my Atmosphere XL4 wave generator. When the Ground Block wasn’t in use, I instead used the Galileo SXes’ included ground cables, plugged into a power-line strip.

Silence is more musical than any song.”
-- Christina Rossetti

The Galileo SXes may well set a new high bar for audio-cable performance. Further, while at first glance their geometries are more similar to than different from those of the Galileo UEFs, the SXes considerably outperformed the older cables.

Not surprisingly, the Galileo SXes have Synergistic’s house sound. If you prefer staid, polite-sounding cables with a heavily romanticized midrange, the SXes are not for you. But that doesn’t mean that the SXes sound coarse, ill-mannered, or amusical. They are to audio cables as Ferrari Monzas are to automobiles -- they deliver not only all the chills, thrills, and spills, but also all the polish, refinement, and sophistication.

Somehow, Ted Denney has made the Galileo SX cables even quieter than the UEFs, whose calling card was their reduction of noise. While this is a genuinely remarkable achievement, it’s not really surprising. If you’re a cable manufacturer trying to improve the sound of your statement products, a good place to start is noise rejection. Still, with “Lucky Seven,” from Chris Squire’s Fish Out of Water (CD, Atlantic ARC-8085 WQCP-1019), the absence of noise was remarkable -- Squire’s bass guitar popped from the mix as I’d never before experienced.

The Galileo SXes were so quiet that, while auditioning them, I heard automobile noises from a distant bridge for the first time. A bit baffled, I varied the times of day when I listened to my system. Particularly late at night, the noise was still there. I then pulled the SXes out of the system, replaced them with the Galileo UEFs, and again listened late in the evening. The bridge noise was still audible, but only barely. To paraphrase Mos Def’s “Mathematics,” the SXes’ backgrounds were “blacker” than midnight on Broadway and Myrtle.

What also surprised me was the way the Galileo SXes’ low noise floor may have been related to their astonishing imaging and soundstaging. In Bettye LaVette’s version of the Who’s “Love Reign O’er Me,” from her Interpretations: The British Rock Songbook (16-bit/44.1kHz FLAC, Anti-/Tidal), the edges of aural images of her voice and the instruments were now so well delineated that my system placed LaVette’s voice in the left of the soundstage, about an inch from the blue power button of my Esoteric Grandioso K1 SACD/CD player. The SXes’ imaging was that focused.

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Cue the peanut gallery’s all-too-common refrain that live music doesn’t image in pinpoints. In reality, live music doesn’t image in flat pinpoints. The very best systems, aided by capable cables, generate deep, three-dimensional, precise images that create the illusion of musicians performing live in the listening room. I don’t think that anyone who pairs a good system with the Galileo SXes will complain of unrealistic imaging. The images I heard with these cables were more three-dimensional and lifelike than I’ve experienced with any other cable loom.

The Galileo SXes also caused my system to create deeper soundstages than it ever had. Never had there been so much vertical air and space in which voices and instruments could appear. With Anne Bisson’s “Do What You Please,” from the sampler Fidelio Reference 2 (CD, Fidelio FACD 910), the distance between Bisson’s voice, dead center on the soundstage, and bassist Jacques Roy, behind and ever so slightly to the left of the singer, now seemed large enough for a person to comfortably stand up in. With every other set of cables I’ve listened to this track through, the two performers seemed to occupy the same vertical plane.

Also remarkable was how sparkling everything sounded through the SXes. This cleanness of sound seemed to let my system reveal significantly more detail -- something else I may have unreasonably come to expect from new statement cables. With Ondekoza’s “Fujiyama,” a percussion track from YG Acoustics’ Test CD II, my system had never better juxtaposed the high-frequency components of drums struck near their rims with the lower-frequency sounds of drums struck close to the centers of their skins.

However, the Galileo SXes’ highly laundered sound seemed to do more than merely facilitate the revelation of hitherto unheard details in recordings. Rather, it represented a qualitative difference in sound from the Galileo UEFs that should be apparent to the listener from the first needle drop. Hopefully, this trait will become part of a new Synergistic house sound.

The Galileo SXes also made possible the greatest sonic envelopment of listener (me) by music (Pink Floyd) of any cables I’ve had in my system. The synthesized wind sounds that begin “Shine on You Crazy Diamond, Parts 6-9,” from Wish You Were Here (SACD/CD, EMI/Analogue Productions 5099952243325), not only spanned the rear of the soundstage, but swept several feet into the room along the sidewalls. With earlier cable upgrades, those sounds had gotten larger, cleaner, and more detailed, but they’d never before reached into the room.

Lastly, I switched out the SX tuning bullets for the UEF bullets. The edges of notes slightly blurred, tiny details disappeared, and the sound lost a bit of pleasing warmth -- all things I’d never missed until I heard the SX bullets. But once I’d heard them, I didn’t want to go back to the UEF bullets.

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The Galileo SXes are indeed audio’s Ferrari Monzas. No other cable I know of is fully competitive with them on any of their strengths: imaging, transparency, speed, leading edges, detail, noise reduction, dynamics. But don’t let my infatuation with their technical prowess diminish what seems to be these cables’ raison d’être: the reproduction of music. They offered musicality in spades, and on several occasions got me up off my couch and dancing. In “Love Reign O’er Me,” they conveyed Bettye LaVette’s emotional intensity to the point that I wanted to cry. Listening to Pink Floyd’s “Shine On You Crazy Diamond” with the lights low, I felt as if I were on a futuristic set from Blade Runner. These cables should appeal equally to your heart and mind.

And by playing with the gold and silver tuning bullets I was able to tweak my system’s sound to get the right mix of factors for my own heart (e.g., warmth, musicality) and mind (e.g., transient impact, detail, soundstaging). Yes, even with the UEF compound, there are cables that provide a more romanticized midrange and even more meat on the bones than did the Galileo SXes. But in my experience, those other cables sound comparatively soft, diffuse, and mushy, more classic Cadillac than Ferrari Monza.

She said, ‘Do you love me?’ / ’I tell her, ‘Only partly. I love my bed and my momma. I’m sorry.’”
-- Drake

When I became an audiophile, a friend cautioned me against falling in love with any audio product. This is particularly shrewd advice regarding cables, where competitors come to market at a rapid pace. Nonetheless, I’m smitten with the sound of Synergistic Research’s Galileo SXes: breathtakingly lively, exciting, and dynamic, yet gorgeously rich, musical, and accurately full-bodied. They are definite contenders for the designation “the state of the art.”

Another loom of ultra-high-end audio cables is on its way to me for review. The cable arms race continues. Stay tuned.

. . . Howard Kneller

Associated Equipment

  • Amplifier -- Esoteric Grandioso S1
  • Preamplifier -- Esoteric Grandioso C1
  • Sources -- Three-box Windows 10 music server with JPlay player, Linn Kazoo control software, JCAT USB and Ethernet cards, JCAT USB Isolator, HDPLEX 200W linear power supply, and iPad Mini 3; Esoteric Grandioso K1 SACD/CD player and Grandioso G1 master clock generator
  • Other electronics -- JL Audio CR-1 active subwoofer crossover
  • Speakers -- YG Acoustics Kipod II Signature
  • Subwoofers -- JL Audio Fathom f113v2 (2)
  • Interconnects -- Synergistic Research Galileo UEF
  • Digital links -- Mad Scientist Audio Black Magic (USB), Synergistic Research Galileo LE (USB) and Galileo (BNC)
  • Speaker cables -- Synergistic Research Galileo UEF
  • Power cords -- Synergistic Research SR25 (power conditioner) and Galileo UEF and Atmosphere Level 3
  • Power conditioners and distribution -- Synergistic Research PowerCell 12 UEF SE and QLS power strips
  • Isolation devices -- Silent Running Audio VR fp Isobase; Symposium Acoustics: Osiris Ultimate and Standard racks, Segue platform, Roller Block Series 2+ equipment support system; Synergistic Research: Tranquility Bases, MIG 2.0 footers
  • Room treatments and correction -- Synergistic Research: Acoustic Art, Atmosphere XL4, Black Box, HFT and FEQ devices; GIK 2A Alpha diffusor/absorber acoustic panels, WA-Quantum Quantum-Sound-Animator
  • Misc. -- Synergistic Research Active Grounding Block, Blue fuses, and Electronic Circuit Transducers (ECTs); Mad Scientist Black Discus Audio System Enhancers and Graphene Contact Enhancer, Hi Fidelity MC-0.5 Magnetic Wave Guides, Telos Quantum connector caps, f.oq damping tape

Synergistic Research Galileo SX Speaker Cables
Price: $17,500 USD/8’ pair, $800/additional foot.
Synergistic Research Galileo SX Interconnects
Price: $7500 USD/1m pair (RCA), $800/additional 0.5m; $9500 USD/1m pair (XLR), $1000/additional 0.5m.
Synergistic Research Galileo SX IFT Jumpers
Price: $2000 USD/pair.
Warranty (all): Lifetime.

Synergistic Research
1736 E. Borchard Avenue, Suite 102
Santa Ana, CA 92705
Phone: (800) 578-6489