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AudioQuest Earth, Castle Rock, and NRG‑4 cables

AudioQuest Earth, Castle Rock, and NRG‑4 cables

Like many enthusiasts, my first system upgrade was a sly one. Having bought a system a couple of years before, I was not in a ‘wife-ready’ position to change a component, but I had a bad case of GAS (Gear Acquisition Syndrome) all the same. So, I swapped out the QED 79 Strand that came free with the system, and replaced it with AudioQuest Type 4. The change was so significant, so immediately obvious, and so beneficial in every respect that it signed me up as a life member of the audiophile club. I may have had my moments of pragmatic disbelief along the way, but that Type 4 experience never quite left me.

So I was keen to try AudioQuest’s new Elements range of interconnect cables, its new addition to the Flat Rock loudspeaker cables, and power cords named after… a house music club in Ciampino, Italy. The music just keeps on coming too, because that Elements interconnect range includes Earth, Wind, and Fire (oh, and Water).

Earth is second in the range of Elements interconnects, with Water cheaper, and Wind and Fire more expensive. It features the company’s PSC+ (Perfect-Surface Copper) conductors in a triple-balanced geometry for accurate ground referencing, air filled tubes of FEP as insulators, a six‑layer carbon insulator ‘noise dissipation’ system that acts to shield the shield, and cold-welded silver-plated copper phono (or XLR) plugs.

Castle Rock loudspeaker cable replaces Gibraltar as the entry level in AudioQuest’s second from the top Flat Rock range (with Comet, Meteor, and K2 further up the Flat Rock mountain). The loudspeaker cable shares the same quality PSC+ copper conductors, but uses a combination of foamed polyethylene insulation for the positive and carbon-loaded polythene as a partially-conductive insulator for the negative conductor. The shotgunned (internally bi‑wired used in single-wired mode) cable uses a double star-quad (Litz) construction, with different sized conductors spread through the layout to reduce the potential for consistent sized conductors creating a ‘signature’ sound.

NRG‑4 power cords also share a lot of design criteria with Earth and Castle Rock, once again featuring PSC+ copper conductors with the ‘multi-position carbon-based noise-dissipation and cross-talk dissipation systems’ (read: insulators) as the loudspeaker cables. The NRG‑4 has a different internal layout, however, with the positive conductors spiralling in an opposite direction to the negatives. The terminations are cold-welded and sit in moulded plugs that you’d struggle to open with a hacksaw. Despite the prefix, NRG‑4 is actually sixth from the entry-point in the power cord line-up from AudioQuest.

, AudioQuest Earth, Castle Rock, and NRG‑4 cables

Both Earth and Castle Rock include the latest 72v DBS (Dialectric-Bias System). According to AudioQuest, DBS eliminates the need to break in a set of cables, by applying a continual charge to the dielectric of the cable. It uses a wire down the middle of the cable itself, attached to the negative pole of the battery box, while the shield is connected to the positive pole. The company further states this creates a DC field with a comparatively high voltage but minimal current draw, so the little camera batteries inside the DBS box last for years. A battery check push-button lights a green LED if the six cells are still alive.

The easiest way of testing DBS is to get two sets of identical interconnects, remove the batteries from one and extract them from the system, while leaving the others with powered-up DBS in situ, which is precisely what I did. AudioQuest also suggests DBS’s dielectric involvement takes time to dissipate, so you need to wait a week or two. Which, again, is precisely what I did.

AudioQuest is built on a bedrock of pure observation. As a consequence, ‘it does…’ is more important than ‘why does it?’ And nowhere is that observational stance more obvious than when dealing with the DBS system. The no‑DBS Earth cable appeared audibly slower, less temporally correct, and less coherent than its batteried‑up counterpart. There’s also a shade more definition and space around the instruments. Not massively so, but enough to make the inclusion of DBS worthwhile. DBS was most clearly missed in playing modern music, like ‘Correspondences’ by Dutilleux [Salonen, OPRF, DG], paradoxically because the dream-like ebbs and flow of music are deceptively precise, so that loss of temporal precision when DBS is removed sometimes undermines the musical whole. It took two weeks for the DBS effect to wear off, a week and a half for it to come back to life, and less than 15 minutes of direct comparison to hear why it matters.

You can get fixated on such things, but in reality DBS simply forms a part of the wider findings about a product. Looking at the gestalt of the Earth cable, it’s a remarkably layered, three-dimensional sound, with plenty of size and scale to the imagery. It manages to be impressive, yet is not flashy or overtly ‘hi‑fi’ sounding. It’s still an upfront presentation; music is not a shrinking violet through Earth, but neither is it zingy and upfront. It’s a sound that is immediately likeable, enjoyable, and entertaining, snapping your attention to focus with ease and charm.

The same applied perfectly to the Castle Rock cables, and the two make a perfect match. It’s an impressive, insightful sound, full of dynamic shading, detail, precision, and large stereo imagery. It’s capable of extracting the inherent qualities of the amplifier without imposing too great a character on the sound.

Meanwhile, NRG‑4 act’s like The Dude’s rug in The Big Lebowski, as it ‘really ties the room together’. The NRG‑4’s influence (like any good power cord) is more icing on the cake than the cake itself, but it helps to order the bottom end slightly, possibly trading depth for speed and texture. That sense of control extended up into the midrange, giving it a poise and harmonic structure that brought out the spatial qualities of well-recorded music, and stopped less-than-well-recorded music from sounding wayward and overtly agressive. NRG‑4 is perhaps not as universal as Earth or Castle Rock, however, because that order and control can make an already taut-sounding system appear overtightened and controlling. If your system needs to let its hair down, NRG‑4 isn’t the power cable for you. Fortunately, hair and I parted company some years ago.

Hi‑Fi+ is perhaps best known for reviewing cables in complete ‘looms’, and AudioQuest’s offerings make a strong case for continuing this method of investigation. This is one of those instances where the whole is better than the sum of the parts, despite the parts being extremely good in their own rights. Candidly, my regular tastes in music probably make me an outlier, but with the complete AudioQuest system helped me find my mainstream musical mojo, because I found myself listening to – and thoroughly enjoying – the sort of sounds I would never normally listen to. My collection of what my wife calls ‘cat strangling’ jazz sounded lithe and detailed, but the AudioQuest package helped me better appreciate Duke Ellington in his earlier (and later) years. It made me discover there were lyricists after Bob Dylan, that rock music didn’t end with Led Zeppelin, and that Mozart isn’t just fluffy chocolate box music. In short, the AudioQuest cables presented the sound so well, I had to temporarily turn off my music snob filter. It’s Type 4 all over again!


In sonic terms, the big bonus of an all‑AudioQuest loom for me was the sheer openness of the midrange, and the effortless dynamics the system seemed capable of. Yes, I’ve experienced similar with some of the Top Table Cable, but I can’t quite shake that ‘no cable should cost more than a car’ meme, and the AudioQuest cable set brings those midrange and dynamics qualities down to my pay grade. That it also does this from a very quiet, precise background and has all the detail a studio engineer would crave, and a sense of temporal order that would make a Time Lord smile, just rams home the message.

, AudioQuest Earth, Castle Rock, and NRG‑4 cables

I’m extremely taken with this AudioQuest cable system. Both as individual cables and as a loom, they have a common aim of producing an impressive sound, but without the brightness and etched qualities commonly associated with ‘impressive’ audio performance. It’s a sound at once upbeat and unforced, a rare combination that is extremely attractive. Even the DBS battery boxes work, keeping your cables in tip-top condition, despite some initial scepticism on my part. It’s clear AudioQuest is listening to its cables empirically, and the Earth, Castle Rock, and even NRG‑4 get my strongest recommendation for real-world audio systems.


Prices (as tested)

  • AudioQuest Earth interconnect cables: £800/1m pair
  • AudioQuest Castle Rock loudspeaker cables: £1,455/3m pair
  • AudioQuest NRG‑4 power cord: £209/0.9m

Manufactured by: AudioQuest

URL: www.audioquest.com

Tel: +31 165 541404


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