I’d like to extend a special thanks to Double Helix Cables founder and owner, Peter Bradstock, for sending us a sample Complement C cable and a set of Triple Threat adapters, without any expectation other than a fair review. Your support is much appreciated.
Preface
It’s been a while since I last concerned myself with headphone cables – or headphones in general, for that matter. For the last few years, I’ve been entrenched in the ‘portable’ side of the hobby, mainly IEMs, DAPs, and their respective ecosystems.
But my personal audio journey began in the world of headphones, and I once again find myself gravitating to the larger, more effortless sound of headphones, despite their portability constraints.
Which brings me to the catalyst for this review: having re-purchased my two long-standing favourite open and closed headphones, Sennheiser’s HD800S and Sony’s MDR-Z1R respectively, I wanted to see which cable combinations would best optimise these classics for my current preferences.
So yes, while this review was borne of a very personal journey (and a rather narrowly-focused one at that), I hope that some of the insights in this review will help to answer any questions you might have about your own setups.
Consummate copper
If there’s one thing I hold true from my own experience over the years, it’s that cables can and do make a difference to the sound of a headphone, and that different cable materials affect that sound in different ways.
Ok, that’s two things, but you get the point. If you’re someone who finds no correlation between cables and the sound of your headphones – relative to the stock cables they ship with – then you’ve saved yourself a 15-minute read. But if, like me, you find that cables do indeed affect at least some aspects of sound, then please read on.
When I started looking at options for the personal project I so eloquently described above, I narrowed them down very quickly with one simple requirement: pure copper.
Without going into extreme (and frankly subjective) detail about why this is so, I’ll just say that when it comes to my sound preferences, I index for bass quality and quantity first and foremost, balanced with the least amount of smooth treble required for a natural-yet-detailed sound. Generally speaking, I find that pure copper cables more often than not hit both of these targets.
That said, pure copper is not the ultimate material if you’re wanting to optimise signal conductivity; that accolade goes to pure silver. But as it turns out, maximum conductivity is not exactly what’s required to shepherd the sound of my chosen headphones closer to my preferences.
Again, speaking in broad strokes, I find most pure silver cables improve resolution and extend the treble response almost to a fault, whereas good pure copper cables help attenuate the treble, softening peaks, and as a result, place more focus to the lower frequencies.
Before you start writing heated comments that there are copper and silver cables that defy these ‘norms’, you’re right. I’ve tried and tested silver-sounding copper and copper-sounding silver cables in the past – admittedly mostly in the IEM world – but there are always exceptions to the rules, so please take my opinions as no more than that.
Still, considering how well-established the headphones in question are for many thousands of users around the world, the accumulated knowledge I’ve read over the years combined with my own experience makes pure copper a pretty safe bet for what I was looking to tweak.
Enter DHC Complement C
So where does one start looking for a pure copper cable that won’t break the bank and still do everything I want for the sound of my headphones? It didn’t take too long to zero in on a small, boutique company called Double Helix Cables, whose reputation seems to be well established in audiophile circles.
Founded by a microbiologist, Peter Bradstock started the company as a hobbyist, looking to optimise his headphone system with the best materials available for the job. That was more than 15 years ago now, and today, DHC’s products adhere to the same non-negotiable principle he established back then: that pure copper and pure silver were the only two materials required to maximise both conductivity and neutrality.
Whatever Peter is doing seems to be working, because with few exceptions, almost everyone I asked about his company and products had only good things to say about them. So I tracked Peter down on Telegram, we started the conversation, and a few months later, here I am with the cable he suggested I start with: the $599 Complement C.
Interestingly, Complement C has its origins in technology Peter developed around the same time my headphones were ruling the roost in 2018. Back then, the ‘Clone’ series perfected the use of dual-coaxial Litz-based cable designs.
Complement C evolves this technology using “ultra-flexible insulation and internal cotton damping – [encasing] a tubular negative conductor braided directly over the cotton-encased positive conductor – which allows for a 18.8awg x 2 design in a single wire that is substantial yet ergonomic.”
Since I’m not looking to drive highly insensitive and inefficient planar or ribbon headphones like Susvara or Immanis, Complement C, with its large gauge, is more than enough for my needs – with plenty of headroom to spare. As a sidenote, for most users, selecting a cable gauge larger than 26awg should suffice for all but the most demanding applications.
According to Peter, Complement C offers “conductivity approaching that of Prion4 (DHC’s flagship large gauge pure silver cable), dwarfs the potential of its predecessor (Complement4), while remaining in the same price bracket and occupying just over half the volume.”
A tried-and-true 18.8awg type 6 OCC Litz layout, shared with Prion4 and Elite19, is employed here – using a combination of 35 Litz groups, six neutral cotton damping cores, and a central carbon anti-static core. Certain sweet spots just “work” when it comes to finding the right blend of detail, realism, and engaging personality in a cable – and the Prion4 pattern is “it.”
Design and fit
The one advantage of having a cable made by a perfectionist like Peter is that the build options are endless and the workmanship is uncompromising. For example, you can order Complement C with or without a y-splitter, allowing for a traditional twisted-pair configuration up to the y-split, or independent left/right cables from amp-end to earcups for true channel separation.
You can also select from a wide variety of sleeving options – though I opted for the “naked” version to show off that glorious copper wire – and a range of standard Eidolic splitters or bespoke custom-made options. Connection options are also varied, but sticking with Eidolic makes sense for maximum compatibility and guaranteed quality.
In my case, since I wanted to test the cable on both of my headphones, I also needed a way to connect them natively to one and adapt them to the other.
It turns out Peter is one of the few manufacturers that custom-makes adapters for this very purpose – and specifically ‘no-cable’ adapters that preserve the sonic qualities of the original cable and giving you direct connector-to-headphone conversion regardless of which cable you’re adapting. Along with Complement C, I therefore received a set of DHC’s ‘Triple Threat’ adapters, with a female HD800S socket at the base and male 3.5mm connectors for the Sony Z1R at the top.
I think you’ll agree that the carbon fibre splitter and connectors on my Complement C, matched with the Triple Threat adapters, befit the premium look of this meticulously-made cable.
If there are any downsides to all this boutique bespoke-ness, it’s possibly build time and communication. Peter is extremely busy, and his cables take time and focus to construct. Each cable (and adapter set) is made by hand, and so I caution users looking for a ‘quick fix’ that going the custom build route with DHC will take some effort and a generous helping of patience.
The reward, however, is worth it.
Continue to sound impressions, pairings and conclusion…
