SOUNDSTAGE! ON HIFIHot Product Archives

Published November 1, 2003


Stefan AudioArt Equinox HD 600/580 Headphone Replacement Cable

Brothers and sisters, I stand before you today as a headphone true believer. Is there anyone here who isn't a headphone true believer?

Yeah, me.

Me, too!

Get those audiophiles out of here. Now close the door.

Now fellow headphone lovers, I want to address a topic . . .

Uh, I want to addr . . .

Excuse me -- you over there -- are you listening to me? Somebody take that dude's iPod away from him.

Now, as I was saying, I want to address a topic that ordinary audiophiles just wouldn't be able to grasp: a specialty audio cable designed specifically for the most comfortable headphones ever made -- and, with the right amp driving them through the right cable, one of the best sounding.

Testify! Testify!

This will go a lot faster if you don't interrupt.

Sorry. I just got carried away.

That's understandable -- it happens to me all the time. Especially now that I've discovered the sound of my Sennheiser HD 600s through Equinox's HD 600/580 headphone cable.

I'm happy -- I'm happy!

I can see it's going to be a looong night.

No! Let me taste the whole of it

You do have to be more than a bit of a headphone true believer to even comprehend why there would be a product like Stefan AudioArt's Equinox HD 600/580 headphone cable. After all, it's a $189 USD wire ($199 if you want a minijack connection) that only fits two models of headphone, Sennheiser's $260 HD 580 and $450 HD 600 (it will also fit the recently announced HD 650, as well -- although Serdechny will have to do extensive testing before he calls it a synergistic match). That's pretty rarified territory -- especially if you consider that most people adding that pricey cable to an already pretty pricey pair of headphones are going to have a dedicated headphone amplifier to boot. If Stefan AudioArt were just doing this to get rich, choosing this line of approach might not be considered a savvy move.

But Stefan AudioArt isn't doing this out of some MBA's desire to dominate the audio industry. Stefan AudioArt is James Serdechny, a lifelong musician who has also worked as an engineer for Sennheiser and has extensive professional experience employing 'phones from Beyerdynamics and AKG. In other words, fellow headphone true believers, he's one of us.

So much so, that he spent years obsessing over the weak link in the headphone chain: the wires themselves. As an audiophile and music lover, Serdechny was aware that headphone sound wasn't all it could be, but as an applications engineer, he was also aware that the best headphone designs had stretched the limits of available technology when it came to driver systems, diaphragm materials, and surrounds. But that darn cable was designed to be flexible, durable, and cheap -- it seemed like no one even considered how it sounded.

So Serdechny did what any music-loving engineer would do -- he embarked on a series of listening tests (a three-year mission) that ended up producing what he describes as "an exhausting number of headphone cable designs." The results were the Equinox HD 600/580 cable for the Sennheisers and a special cable for the AKG K1000.

The HD 600/580 cable sports Sennheiser's proprietary "spade" connectors -- which is what makes the cable a dedicated Sennheiser cable (d'oh!). But "spade" in this case does not refer to the conventional massive fork that fits onto a speaker's binding post. It’s a tiny (1/8") two-pronged push connector (the prongs are different diameters, insuring correct polarity to the drivers) that connects to the cable within a molded plastic housing. The point where the terminations are coupled to the wire is covered in six layers of heatshrink tubing, ensuring a solid and lasting junction. Serdechny maintains that this is the best option for a variety of reasons -- sound, strain-relief, and appearance.

The cable itself is a "four-conductor, quad-braid, field geometry cable consisting of ultra-high-purity copper with individual strand isolation, enclosed with a Teflon/Oxygen dielectric, finished in black Techflex with white cabling," according to Stefan AudioArt's literature. What that means is that it's a braided design where each of the four conductors contains a smaller group of wire strands which are encased in Teflon dielectric. These sub-groups are composed of individual strands that vary in diameter in a configuration that Serdechny found synergistic with the HD 600 and 580 headphones. The four Teflon-clad conductors are braided together and covered with black Techflex from the connector to the first 8' 5" of the cable. In the remaining 12" (a 9' Equinox cable set is actually 9' 5" long -- all the Equinox cables are 5" longer than there stated length), the four braided sub-groups are paired into loosely twisted pairs, extremely flexible, that connect to each of the headphone's earpieces.

You can buy the cable with several different terminations: my review cable came fitted with an extremely high-quality (and substantial) 1/4" termination, although it is also available with a heavy-duty 3.5mm minijack and a mini-to-1/4" adaptor ($199 for the minijack/adaptor version; $189 for the 1/4").

The connectors are fused to the cable with Stefan AudioArt's proprietary Ultra-Solder process, which incorporates a scrupulous cleaning process Serdechny seriously describes as "sterilization." He told me that, far from being a minor step in the assembly process, this cleaning improved the cable's sound more than many materials changes he could have incorporated. (In fact, he attributes the improvements I heard in his most recent iteration in the cable exclusively to his "sterilization" process.) A critical stage of the Ultra-Solder process is ultrasonic cleansing of the termination points.

The cables are heat-treated to increase their overall flexibility. Serdechny claims this process improves the flexibility of the cable by increasing the gap between the wire and the Teflon dielectric. I have no way of evaluating this, of course, but the Equinox cable is marvelously supple, so I certainly have no reason to doubt it.

Happiness is a wine of the rarest vintage, and seems insipid to a vulgar taste

I listened to the Equinox HD 600/580 cable through a HeadRoom Max and my HD 600s. I checked the Equinox with my ancient HD 580s, just to determine that the combination worked without any major glitches, but the majority of my listening employed the 600s. Digital sources included an Audio Research CD3, Ayre AX-7, Classé CDP-10, and my iPod (where the HD 600/Equinox combo represented a greater investment than the source component, tee hee). Interconnects between source and HeadRoom included Kimber KCAG, Kimber 3 mini-to-RCA (iPod), and Shunyata Research Aries. I used Shunyata Research PowerSnakes Diamondback AC cables to power the CD players and Max.

Everyone carries his own inch-rule of taste

Assuming you didn't stop reading this when you discovered it was about a headphone cable, you might be wondering what's the big deal about the Sennheiser HD 580s and HD 600s. Headphones, like speakers and, I suppose, just about everything else, are a very subjective item, but there is a consensus among a large cross-section of headphone users that these two headphone models rank among the best choices out there. They are extremely comfortable to wear, and both models feature detail and finesse over the entire musical spectrum. The HD 600s are -- at least to my way of thinking -- quite a bit better than the 580s, but both models feature full-bodied bass, an eminently listenable midrange, and clear, extended high frequencies. The stock models of both headphones are, in other words, not too shabby.

But if you're an audiophile (and pretty much anyone who owns a pair of headphones that cost more than $200 must be considered an audiophile), the one constant factor in your quest for musical ecstasy is an overwhelming desire for mo' bettah. And that's a hope that the Equinox undeniably delivers on.

The HD 600's biggest draw for many listeners is its rock solid bass response, and this is an area where the Equinox made a substantial improvement. Building on the headphone's already impressive solidity and control, the leading edge of the attack transient seemed sharper and better defined, making recordings that prominently feature the bass guitar, such as Carla Bley's Looking for America [ECM/WATT 31], slam home with all the solidity of a fist in the solar plexus (which is a lot more satisfying than it sounds).

The Equinox also improves upon the 600's innate silkiness in the high frequencies. Not a lot, since there doesn't seem to be a lot of room for improvement in this area -- at least to my way of thinking -- but an improvement nonetheless.

This is particularly noticeable in the most simply recorded acoustic music, such as Deep River [CTS 1203], the new recording by Cantus. Deep River was laid down in the 1800-seat Great Hall of the Husby Performing Arts Center in Sioux Falls' Washington Pavilion of Arts and Science, which has a gloriously ringing acoustic. The Great Hall's sound is so supportive that that you could jump off one of its balconies and float to the ground on a cloud of reverb -- and with the Equinox you can hear that clangy cushion of decay fade and fade and fade (still going!) and fade some more.

But as impressive as all this is, it's what the Equinox does in the midrange that qualifies it for beatification. Here, the improvement over the stock HD 600 is phenomenal. Everything hangs together from top to bottom, but the stuff in the middle is the creamy filling -- and you'll want to eat it right up.

Tight brass harmonies, like the ones Carla Bley charts for the small brass ensemble on Charlie Haden's The Ballad of the Fallen [ECM 811546], just resolve like crazy (Jim Pepper and Steve Slagle, saxes; Gary Valente, trombone; Sharon Freeman, French horn; Jack Jeffers, tuba). There's a small amount of warmth, perhaps, but it doesn't interfere with the 600's ability to shine a light on those luscious inner voices.

Oh my.

That depends upon the taste and fancy of the speller, my Lord

Moving away from the stock cable on the HD 600, there are essentially two main choices besides the Equinox: the $119 Clou Cable 212 Red Jaspis headphone replacement cable and the $150 Cardas Cable replacement cable (not reviewed here -- yet).

The Clou has a lot going for it. It unquestionably offers improvement over the Sennheiser stock cable, but it doesn't match the Equinox's top-to-bottom coherence or smoothness. In fact, it sounds awfully bright now that I've heard the AudioArt cable. In addition, I found the Clou unwieldy to use -- it is stiff and heavy, and these properties proved to be major irritants when I was actually working. (Yes, monitoring recording sessions is work!). The Equinox seems about half the weight of the Clou and it is superbly flexible -- it flows like quicksilver.

The Cardas is a different kettle of fish entirely. I'll return to this cable for a full review later, but the short version is that it matches the Equinox for coherence, but errs (if you call it erring) on the lighter, more detailed end of the presentation spectrum. While I find the Equinox's top-end extension is essentially similar to that of the unmodded HD 600s, only more mwaah satiny, there's no question that the Cardas is even more open and, well, extended.

Which cable you'll prefer will depend largely on whether you value warmth more than brilliance. If you value warmth, the Cardas will seem cold and, perhaps, too revealing. If you just want the facts, thank you very much -- well, you might find more "truth" in the Cardas.

Critic: a bundle of biases held loosely together by a sense of taste

Do I like the Stefan AudioArt cable? Do I ever!

It isn't cheap, but its price isn't astronomical as cable prices go. James Serdechny told me that it initially took between six and seven hours of labor to produce the Equinox, although he has refined that to just under four -- hey, he is an applications engineer. Even so, that means he's working for a lot less per hour than I'd want to (actually, considering what a slow writer I am, let's not go there). For a limited-production, limited-market, high-labor niche item, the price seems pretty reasonable.

And, if the proof of the pudding is in the tasting, the Equinox is well worth the freight. If you listen to Sennheiser HD 580s or 600s and want even more of what you love about them, you owe it to yourself to experience them with the Stefan AudioArt Equinox cables.

It'll make a true believer out of ya.

 ...Wes Phillips

Stefan AudioArt Equinox HD 600/580 Headphone Replacement Cable
Price: $189 USD (1/4" jack); $199 (minijack with 1/4" adaptor).
Warranty: One year parts and labor; 30-day money-back guarantee.

Stefan AudioArt
115 Grennan Road
West Hartford, CT 06107
Phone: (860) 313-8088
Fax: (860) 313-8088


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