QED Reference Audio 40 review

QED’s latest iteration of its esteemed mid-ranging interconnect has big shoes to fill Tested at £94 (1m) / $169.95 (1m) / AU$199 (1m)

Interconnect: QED Reference Audio 40
(Image: © QED)

What Hi-Fi? Verdict

A recommendable and well-built all-rounder, if not the most musical at its price


  • +

    Compellingly big and clear soundstage

  • +

    Impressive clarity

  • +

    Quality build throughout


  • -

    Falls short of class-leading musicality

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It’s almost as if the QED Reference Audio 40 is aware it’s the middle child in the company’s analogue interconnect range (between the entry-level Performance and flagship Signature series). Adamant not to be ignored due to its rank order, it demands that your music sound big, clear and imposing. This is no bad thing – the QED does this in a pleasing way, prioritising clarity to help your music sound compellingly front and centre in your system’s soundstage. 

The previous iteration of QED’s Reference Audio 40 was a five-star cable we praised for relaying music with depth and dimension in an expansive soundstage, and those same characteristics certainly shine through here to make a solid first impression. That impression doesn’t waver as we make our way through our playlist – from jazz to rap to classical – over the course of our testing. It’s quite easy to fall for the cable’s showy, brightly lit nature, with the treble frequencies slightly (but not too overly) emphasised, and that’s nicely balanced with a sense that the QED is striving for technical correctness too.

There isn’t quite the same natural approach of the Atlas Element Achromatic, though, and we find the more musical Chord ClearwayX (and, to a lesser extent, even Chord’s more affordable C-line) a better communicator of dynamic expression and rhythmic cohesiveness. It’s fair to say the QED shares more of the talents of a public speaker than a born entertainer, then.


Interconnect: QED Reference Audio 40

(Image credit: QED)

QED can put the cable’s clear, refined and ultimately capable performance down to the upgrades it has made to bring this cable into the next generation. The British brand has built on the success of its first-gen Analoc plug design with what it fittingly calls Analoc2, which promises to quash the detrimental effects of pesky eddy currents more efficiently than in the isolated metal body of the previous plug design. To do this, QED has swapped in thermoplastic material for both the inner support structure and the cable strain relief, while still pairing copper connectors with metal barrels. 

Moving away from the plug and down to the cable, two silver-plated (and supposedly almost entirely oxygen free) copper conductors carry the audio signal, with each a different diameter to, QED says, provide an alternative path for the high frequencies that could become time-smeared within a single pathway.

QED Reference Audio 40 tech specs

Interconnect: QED Reference Audio 40

(Image credit: QED)

Conductor material 2 x copper

Length 1 metre

Dielectric material Polyethylene (LDPE)

Connector options RCA

Polyethylene (LDPE) for the inner jacket is the dielectric chosen to work alongside the conductors and reduce electrical energy loss. And lastly, a Zn/Mn Ferrite jacket has been chosen within the cordage in a bid to absorb unwanted high-frequency noise. Considering the clean, clear nature of the cable, we’d say it's a job well done here.

If the Reference Audio 40’s sonic characteristics sound like just what your system needs, know that nothing about its physical makeup should put you off. You can tell the cable’s high build quality before having to handle it to confirm it, and it’s not only a pleasingly built thing but also an attractive one thanks to its red braided cable inside the translucent jacket.


Interconnect: QED Reference Audio 40

(Image credit: QED)

The QED Reference Audio 40 might not tick every sonic box as boldly as its highest-level competitors at the price point, but there’s a lot to be said for a cable that can relay music with class-leading clarity and a stark radiance. And for that reason, it continues the model’s favourable legacy.


  • Sound 4
  • Build 5
  • Compatibility 4


Also consider the Chord Company ClearwayX

And the Atlas Element Achromatic

Power chords: the best interconnects you can buy

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What Hi-Fi?, founded in 1976, is the world's leading independent guide to buying and owning hi-fi and home entertainment products. Our comprehensive tests help you buy the very best for your money, with our advice sections giving you step-by-step information on how to get even more from your music and movies. Everything is tested by our dedicated team of in-house reviewers in our custom-built test rooms in London, Reading and Bath. Our coveted five-star rating and Awards are recognised all over the world as the ultimate seal of approval, so you can buy with absolute confidence.

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  • abacus
    Verifiable evidence please, or if non available say it’s in the reviewers opinion rather than giving the impression that it is fact.

  • Combat
    abacus said:
    Verifiable evidence please, or if non available say it’s in the reviewers opinion rather than giving the impression that it is fact.

    Lol, totally. It took me years to realise that the main reason What HiFi existed was not because of their love HiFi but because of their love of sponsored snake oil. Its a shame that they still do it because in this day and age it kills their credibility. I mean if they will take money to write a review about a cable then think about the rest.
  • Gray
    In the review, the sound of the QED is being compared to cables from other brands.
    Would WHF be able to identify each in a blind test?
    Cable believers always avoid the question of blind tests, saying that they prove nothing (whereas of course, they could prove everything).
    What's WHF's excuse? Surely they should be able (and willing) to do their own blind tests - if the differences are as described in the review, then surely they're readily identifiable in unsighted tests.
  • Navanski
    I have to agree with all the previous comments, in particular the absence of objective/subjective proof, the blind test. In addition I would have to suggest that QED are providing some real mumbo jumbo.
    According to QED, in this cable 'copper conductors carry the audio signal, with each a different diameter to, QED says, provide an alternative path for the high frequencies that could become time-smeared within a single pathway.' This suggests that the HF signal travels at a different speed dependant on the diameter of the conductor. I'm not in a position to dispute that. Surely, however, the high frequency signals now have two conduits with two different arrival times at the destination. I'd say the differing conductor diameter, if anything, increases the time smear. Then again we are talking speeds of around C*0.5 to C*0.98 so over a 1 metre cable I calculate it to be a maximum of 1.5 nano seconds.