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ASA Adjudication on Russ Andrews Accessories Ltd

Russ Andrews Accessories Ltd

Edge Bank House


12 January 2011





Number of complaints:


Complaint Ref:



A brochure for audio equipment featured a number of products that Russ Andrews Accessories claimed could reduce Radio Frequency Interference (RFI) from mains electricity, which, they maintained affected the quality of sound on hi-fi equipment. The brochure stated how Russ Andrews Accessories had commissioned their own research into claims that it had previously made about the technology, which, they explained, had been found to be unsubstantiated when previously investigated by the ASA in 2008.

Russ Andrews Accessories now felt that they had proof to support the claims, such as, "As with all our PowerKords, the woven design is proven to reduce RFI on the mains supply … allowing a sound that is fuller, more natural and more musical". A section of the brochure was headlined "measuring the RFI problem". It explained "the effect it [RFI] has on Hi-Fi equipment and why our cables are in such a good position to reduce the degradation RFI causes to Hi-Fi and Home Cinema components". Another section was headlined "Don't let interference ruin your music" and detailed the testing that Russ Andrews Accessories had had carried out. It stated "The results typically show a reduction in RFI ranging between three and ten times".


The complainant challenged whether:

1. Russ Andrews Accessories could substantiate the implication that RFI from mains electricity was a perceptible problem that effected Hi-Fi and Home Cinema systems; and

2. the ad was misleading, because he believed Russ Andrews Accessories' research did not support the claims that the cables could reduce mains-borne RFI beyond the reduction supplied by a standard mains cable.

CAP Code (Edition 11)


1. Russ Andrews Accessories Ltd (Russ Andrews) said the link between various forms of RFI and electromagnetic interference (EMI) had been established for many years. They cited and sent copies of a series of articles, appearing in various specialist hi-fi magazines over the past 30 years, which were based on subjective listening tests and some objective measurement of the phenomenon. Russ Andrews maintained that this information established that RFI was a widely accepted problem. Furthermore, they pointed out that research they had commissioned established and measured the link between the presence of RFI on the main and raised distortion levels in power amplifiers.

Russ Andrews nevertheless maintained that the claims were statements of opinion because a listeners perception of sound was purely subjective. They maintained that the expert advice cited in the ASAs adjudication in 2008 was flawed in objecting to the relevance of subjective evidence such as testimonials. They believed the ABX testing method suggested by the expert in that case was inappropriate as it had been widely disputed that audible differences could be measured and quantified. Russ Andrews provided a series of statements from industry academics, reviewers and manufacturers supporting their view that the statements were reasonably seen as subjective. They added that the hi-fi accessories field was a specialist area where consumers were likely to be knowledgeable about the issues involved and were unlikely to understand the claims in a strict objective manner.

2. Russ Andrews sent a copy of a study entitled Interference and Distortion Reducing Capabilities of Woven PowerKords, which they had commissioned following the ASA adjudication in 2008 and which, they maintained, supported their claims that their products could reduce mains-borne RFI. They pointed out that the study demonstrated that amplifier noise and distortion levels were altered by RFI, and that the RFI-reducing properties of woven cables could reduce that effect significantly. They said the study showed the conduction path for RFI into an amplifier through its mains input, the radio reception properties of a mains cable and provided an analysis of high frequency noise on the mains. They maintained that the topology and equivalent theory of woven cable was shown to be in agreement with the observed results.


1. Upheld

The ASA noted Russ Andrews argument that the issue of the effect of mains-borne RFI was subjective and therefore did not require objective substantiation. We also noted supporting statements provided, at Russ Andrews request, by a variety of industry sources. We noted the ad explained that RFI entered an audio system in two ways: by being picked up from radio signals in the general environment and via the mains supply. We noted in particular the ad emphasised the degradation to sound quality caused by mains-borne RFI and the implication that Russ Andrews products could mitigate it.

We acknowledged that specific subjective references to the qualities and properties of sound, in claims such as ... a sound that is fuller, more natural and more musical" were likely to be regarded by consumers as statements of opinion. However, we considered that readers were likely to infer from the ad that mains-borne RFI was a potentially serious and perceptible problem for hi-fi and home cinema systems.

We noted the ad explained the testing Russ Andrews had had carried out to demonstrate the effectiveness of their products; we noted the report, cited by Russ Andrews, attempted to objectively assess mains-borne RFI. However, we were concerned that Russ Andrews had presented insufficient evidence to support such strong claims in relation to the perceptible effect of mains-borne RFI. We noted Russ Andrews concerns, and those of the testimonials forwarded in the response, over the comments of the ASAs expert in the 2008 investigation. We noted, however, the reference to the ABX test was cited as a suggestion of a possible approach to securing more robust substantiation.

Because we had not seen sufficient, robust evidence to demonstrate the perceptible effect of mains-borne RFI on hi-fi and home cinema systems to the levels suggested by the ad, we concluded that the ad was likely to mislead.

On this point, the ad breached CAP Code (Edition 11) clauses 3.1 (Substantiation) and 7.1 (Truthfulness).

2. Upheld

We sought expert advice on the studies cited by Russ Andrews in support of the claims that their PowerKords products could reduce mains-borne RFI.

The expert said the design of PowerKords products rendered them incapable of having a beneficial effect on both modes of RFI: the differential mode (DM) and common-mode (CM) noise voltages and currents. He explained that RF voltages and currents had two modes of propagation along cables, which applied to mains power cables, such as those sold by Russ Andrews. The expert pointed out that both CM RF noise and DM RF noise caused interference problems for audio functions, but highlighted that the design of the product meant it was only possible for it to be effective in filtering DM RFI. The expert pointed out the products were two-core alternating current (AC) mains power cables in which the two cores were split into many strands acting as distributed constant RF filters. He said CM noise bypassed such methods of attempting to limit it and would thereby affect any device using a power lead such as the PowerKords products.

The expert said the test studies provided by Russ Andrews focused only on DM RFI, whereas in practical use a product would be subject to both DM and CM noise. The expert said, if one wanted to reduce the RFI from radio and TV broadcasts on electronic equipment such as audio products, the CM RF noise should be addressed first because it was almost certain, in most situations, that CM RF noise would be significantly worse than the DM RF noise from the same broadcasts. The expert went on to say the test also did not connect a protective conductor in the mains lead (i.e. the green or green/yellow insulated wire) which rendered any results unrepresentative of a device for which, in proper usage, a protective conductor would be connected. The expert also said the test terminated the DM operation of the PowerKords products with a purely resistive 50 Ohms at both source and load. He pointed out that such DM termination impedances were also unrealistic and that typical impedances typical of real-life applications could give different results.

We considered that readers were likely to infer from the ad that the PowerKords products were effective in reducing mains-borne RFI beyond the reduction supplied by a standard mains cable. We considered that, because the products did not have an effect on CM RFI noise, and given the experts concerns about the lack of protective conductor and unrealistic termination impedances in the testing of DM RFI noise, the evidence we had seen was not sufficiently robust to demonstrate that the PowerKords products were effective in reducing mains-borne RFI. We concluded that the ad was likely to mislead.

On this point, the ad breached CAP Code (Edition 11) clauses 3.1 (Substantiation) and 7.1 (Truthfulness).


The ad must not appear again in its current form. We told Russ Andrews not to imply that RFI from mains electricity was a perceptible problem or that their products could reduce mains-borne RFI beyond the reduction supplied by a standard mains cable, unless they held robust substantiation to show that was the case.

Adjudication of the ASA Council (Non-broadcast)

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