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Nordost Sort Isolation System

Why should we spend valuable time and money researching and acquiring aftermarket resonance-control devices? Because they can bring about substantial improvements in system performance. While I’m not wild about adding another complexity to my system or finding more ways to spend money, I am also results-oriented and have heard truly remarkable sonic improvements through the careful application of resonance-control devices—not only in my own system but in other systems as well. In some cases, they have changed the treated system from aggressive and rhythmically stuttering to neutral and wonderfully free-flowing.

In my experience, the first rule of using aftermarket resonance-control devices is to experiment. Place footers in different locations under the equipment or try orienting them up and down. Try different shelves. Try different combinations of the two. What works with one component may not work with another. The resulting interactions among components, footers, and supporting structures—including the room—can vary greatly. The basic protocol applies: Alter only one variable at a time and use the A/B/A comparison method. It takes time and effort, but the results can be worth it.

Nordost offers three resonance-control devices as part of its Sort System line: the Sort Kone (four models, for use under electronics), Sort Füt (height-adjustable heavy-duty feet used under racks and speakers), and Sort Lift (cable lifters). If you haven’t noticed, Nordost uses Scandinavian words in its product names. Nordost means northeast in all of the Scandinavian languages. Sort means black in Danish, a reference to “black background.” Nordost makes products that are designed to reduce underlying noise artifacts, which results in a “darker background.” I can verify that all three of the Sort products do just that to varying degrees, which I will cover with each product below.

Sort Kone
All Sort Kone models share the same basic design; their materials and prices differ accordingly. AS ($70, not supplied for this review) uses an aluminum post and base with a hardened-steel coupling ball. The other three all use a ceramic ball instead of a steel one, but their posts and cone base materials differ: AC ($85 per unit) = aluminum; BC ($149 per unit) = bronze, and TC ($370 per unit) = titanium. Rather than attempt to isolate the supported component from external vibrations, Sort Kones are designed to create an effective mechanical grounding path for the resonances within the electronics and shunt them into their supporting structures. Nordost says the Sort Kones act like a diode, letting unwanted vibrations drain out of the electronics but preventing extraneous vibrations from coming in. The instructions recommend positioning the cones with their points facing upwards, touching the bottom of the component. These “points,” by the way, do not terminate in a sharp tip but in a truncated cone—a flat, disc-like surface that is about ¼” in diameter. The instructions also give some helpful tips on where the user should place Sort Kones for maximum performance, such as under transports, transformers, and output tubes—i.e., parts that are prone to generating strong vibrations. I followed all recommendations and used three cones per chassis. I did not experiment with a four-cone configuration.

Do Sort Kones reduce apparent background noise? Yes. All three auditioned models reduced haze between images and throughout the larger soundscape. They helped contribute to a more organized and less splashy presentation compared to most of the tested components’ stock feet. As a result, images were more focused and the whole listening experience became more relaxed and involving. In ascending price, each model more effectively brought forth details and spatial information. Each also tended to change the apparent tonal center of focus in the following ways: AC seemed to strengthen the lower midrange and correspondingly reduce the upper midrange and lower treble, as if it had applied a slight so-called “BBC dip” (2kHz–4kHz) to the sound; BC seemed to widen the component’s effective operating zone and moved the tonal emphasis closer to the center of the midrange, reducing the BBC dip effect but not completely eliminating it; TC was by far the least colored and most rewarding musically. It seemed to allow its supported component to retrieve details and portray dynamic contrasts markedly better than the other two models. TC costs a lot more than AC or BC, but its performance jump is commensurate with its price.

I compared all three Sort Kone models to Stillpoints Ultra SS footers ($249 each) under every component in my system. (One component was tested on different shelves.) I also compared the Sort Kone models to Ultra SS in a friend’s system under his Esoteric X-01 D2 CD/SACD player with completely different shelving and room characteristics than those of my system. No matter the component or supporting shelf, the results were consistent in the two systems. Stillpoints did not alter the apparent zone of tonal emphasis, except to allow the components to play better at the frequency extremes. This made bass lines a bit more defined and extended, and upper-frequency definition and “air” more apparent. With the Stillpoints, some of the musical verve and immediacy also returned, whereas the Sort Kones—including the TC—tended to tame some of the music’s spontaneity and rhythmic momentum, while reducing background haze.


Compared to Ultra SS, Sort Kones—including TC—also tended to push the front of the soundstage back farther, and did so without a corresponding deepening of the soundstage. The end result yielded a small reduction of perceived soundstage depth. Width was also slightly reduced with Sort Kones. I could not discern any appreciable difference in image height between TC Sort Kones and Ultra SS. Overall resolution was also better with the Ultra SS and, more importantly, the musicality quotient—the emotional connection and artistic expressiveness in the music—was undeniably more apparent with Ultra SS in the mix.

My audio buddy, in whose system we also compared all of the Sort Kone models, confirmed exactly what I was thinking about the whole exercise without any prompting from me. I realize this is the opposite result TAS contributors Charles Zellig and Jay Clawson wrote about in Issue 248 in their series on “New Methods for Quantifying Sonic Performance.” I don’t know what to make of the Zellig-Clawson findings, as I usually hear many of the same sonic characteristics my fellow writers describe. In this case, all I can say is that these results are a good example of how system variables and personal responses to a given device come into play. Were Sort Kones preferable to stock feet? Most definitely, yes. Would I use Sort Kone if I did not have access to Ultra SS footers? Yes. My personal preference is for Ultra SS, though.

Sort Füt
As mentioned, Sort Füts are designed for use as replacement for stock audio rack and speaker footers. They screw into the rack or speaker base with threaded studs and raise the speaker or rack height by about 2.75″. Nordost offers some Sort Füt accessories that you can add to your installation as you see fit. Sort Kup ($299/four) is a matching floor protector that accommodates the dome shaped Sort Füt “tip.” Sort Lock ($179/four) is a large, visually-matched, finger-adjustable nut that allows you to lock in height adjustments so you can be sure the Füt stays in place, and also so you can easily return to a particular setting if you need to. I have a carpeted listening room, so Nordost did not send any Sort Kup, but it did include Sort Lock, which I used.

Nordost also offers a Premium Package ($1500), which includes four Sort Füt, an adjustment tool to make raising or lowering Sort Füt easier, a laser-equipped level, instructions to aid in precise speaker positioning, and an assortment of 8mm, 6mm, and other threaded mounting adapters. The Premium Package costs $100 more than a set of four Sort Füt on their own. You could go to a hardware store and buy a similar laser level for less than $100, but the Premium Package also includes an attachable laser-focusing device and a small plastic target to make speaker matching adjustments easier than a standard laser level would. I also found the custom adjustment tool came in handy. The fit and finish quality of Sort Füt is quite high.

Because changing out the existing spikes on my speakers and rack to Sort Füt was not a quick or easy task, I was not able to use the standard A/B/A evaluation method. However, I can report that I liked everything I heard with Sort Füt in my system. I do not believe I am too far out in pure speculation territory to attribute the following sonic improvements to Sort Füt and the Premium Package: greater sonic ease and less edginess, an improvement in subtle detail retrieval, and more coherent dynamics. Music just sounded more focused and less jumbled, as if small timing errors had been corrected. While I noted those improvements when Sort Füt were installed under my speakers, I believe the greatest improvements were wrought by using Sort Füt under my primary equipment rack (a wood and MDF unit made by QS&D with adjustable spikes for each shelf). Sort Füt helped ratchet up my system’s performance across the board without any apparent downsides.


Sort Lift
Logically, lifting speaker cables off the floor would not necessarily bring noticeable sonic benefits, but I have found that it usually does. And the means for getting them off the floor does seem to affect sound quality, too. I will leave it to others to speculate about the possible reasons for this effect (static build-up, dielectric interference, vibration reduction) and to critics to dismiss the whole idea as pseudo-science and condemn cable lifters as “snake oil.” All I can say is that I prefer to get my cables off the floor—all cables. Sort Lift will work with speaker cables, both the flat ribbon sort (à la Nordost) and traditional round ones, as well as with power cables and interconnects. I used them solely with round speaker cables.

Over the years, I have tried DIY wood blocks, ceramic cups, purpose-made foam lifts, and ones made of high-carbon-content plastic. All were better than leaving the cables on the floor, but they all also had a common shortcoming—the cables were easily nudged off their lifts. Nordost has solved this problem. Each Sort Lift has a heavy metal base, two flexible, opposing, vertical loops, and two small horizontal spring-loaded support cables, all of which form a rather tall three-point-contact “cradle” into which you slide the cable from above. The audio cable maintains its secure position even if it is jostled. Ingenious.

Positional stability is well and good, but what about any sonic improvements?

With Sort Lifts deployed in my system, the soundscape opened up with a greater sense of air and space than with no lifts at all. I had the impression that Sort Lift was, indeed, allowing more subtle spatial cues to come through. I was able to get a clearer picture of “a chorus in a hall” in Morten Lauridsen’s “O Nata” from Lux Aeterna [Hyperion], for example. I also noted a slight reduction of tone color. Some recordings benefited from the open airiness of Sort Lift, while others seemed to lose some of their impact from that apparent reduction in tonal density. The round speaker cable I used has a diameter of about 1.35″, so the Sort Lift might have gripped a cable of this thickness too tightly to work as intended.

I compared Sort Lift with Shunyata Research’s older model Dark Field Elevator v2 ($295 for 12, now replaced by the DFSS model) in both my system and in my audio buddy’s. In my system, the DFE v2 pretty much maintained the same tonal characteristics without cable lifts, but simply improved overall resolution and background quietness, although more subtly than Sort Lift did. In my audio buddy’s system, Sort Lift reduced background noise and enhanced upper-frequency information as it did in my system, but also notably increased liveliness, transient crispness, and overall musicality and resolution. His listening room has hardwood floors, whereas mine has carpet over concrete slab. He uses Cardas Clear Beyond speaker cable; I use Shunyata ZiTron Anaconda (which has its own internal static-reduction technology). The DFE v2 influence on both systems was subtler. The Sort Lift effect was more obvious. Whether either one will appeal in your system is up to you. Sort Lift really elevated (no pun intended) my friend’s system performance to a degree that I did not think was possible by means of such a seemingly simple device.

Entire Sort System
Nordost sent enough Sort Kone AC, Sort Füt, and Sort Lift to kit out my entire system. So what did it sound like? Clean, coherent, calm. The background noise was, indeed, reduced all around. Musicians’ positions in space and the overall sonic envelope were fleshed out very well. All good things, except I couldn’t shake the feeling that some of music’s inherent sparkle and verve was also reduced along with the background noise. This could be because of the effect of a full system’s worth of Sort Kone ACs, as I had the same impression when I evaluated the Sort Kone models separately. I believe the performance of all vibration control devices is highly system dependent and also affected by the supporting “ecosystem” (rack, shelving, room, etc.) Your preferences may differ from mine.

Nordost has taken a logical approach to vibration control: Create an effective mechanical ground path for spurious vibrations within components to drain into their supporting structures. The sonic results can vary greatly depending on a myriad of factors, such as the resonant characteristics of interfacing component and supporting structures. All of the Sort Systems products appear to be well made and should hold up over time. Sort Füt impressed me the most, and its Premium Package does offer some useful additions. A qualified recommendation with the proviso that you should audition Sort devices in your own system before you buy.

Specs & Pricing

Sort Kone
Type: Vibration-control cone placed under electronics
Weight limit: 100 lbs. per unit
Height: 2.2″
Prices: AS $69, AC $84, BC $149, TC $369 (each)

Sort Füt
Type: Threaded vibration-control feet mounted under audio racks or speakers
Weight limit: 200 lbs. per unit
Height: 2.75″
Price: $350 (each), Premium Package $1500, Sort Lock $179 (four), Sort Kup $299 (four)

Sort Lift
Type: Signal and power cable lifter
Height: 3.30″ (raises cable about 1″ off the floor)
Price: $599 (pair)


93 Bartzak Dr.
Holliston, MA 01746
[email protected]
(508) 893-0100

Associated Equipment
Analog source: Basis Debut V turntable and Vector 4 tonearm, Benz-Micro LP-S MR cartridge
Digital sources: Ayre C-5xeMP, Esoteric X-01 D2, HP Envy 15t running JRiver MC-20, Hegel HD30
Phonostage: Moon by Simaudio 610LP
Line stages: Ayre K-1xe, Hegel P30
Integrated amplifier: Hegel H360
Power amplifiers: Gamut M250i, Hegel H30
Speakers: Dynaudio Confidence C1 Signature, YG Acoustics Sonja 1.2
Cables: Shunyata ZiTron Anaconda signal cables, Nordost Heimdall 2 USB, Audioquest Coffee USB and Hawk Eye SPDIF, Shunyata Anaconda S/PDIF, Shunyata ZiTron Sigma power cords
A/C Power: Two 20-amp dedicated lines, Shunyata SR-Z1 receptacles, Shunyata Triton v2, and Typhon power conditioners
Room treatments: PrimeAcoustic Z-foam panels and DIY panels

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