Connected Fidelity RF Blocker


The RF Blocker is entirely passive, has no effect on impedance or any other amplifier/speaker characteristics other than eliminating a broad spectrum of radio frequencies

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RF Blocker

RF Blocker

A wide-band radio frequency filter that increases audio fidelity.

The connected-fidelity™ “RF Blocker” is a simple to fit radio frequency (RF) filter array.

It is supplied in pairs and there are three connection options – banana and spade terminals, or bare wires.

They simply fit across the loudspeaker + and – input terminals (or amplifier loudspeaker outputs).

RF Noise

RF ‘noise’ (WiFi and all other radio signals) is picked up by all cables, electronics and loudspeaker coils unless perfectly screened against RF.

RF does ‘interfere’ with the audio signal so filtering out RF noise is an effective way of improving audio fidelity.

The RF Blocker is entirely passive, has no effect on impedance or any other amplifier/speaker characteristics other than eliminating a broad spectrum of radio frequencies, both going into the loudspeaker from the amplifier and RF re-entering the amplifier’s circuit via the loudspeaker cable.

The resulting increase in audible fidelity is usually clear to hear as an increase in musical coherence, the high frequencies are clearer, mids cleaner, the bass tighter and less ‘boxy’, the sound stage improved.

The overall effect is of less ‘confused’ musical details, getting you closer to the musical event.

As amplifiers and speakers are designed and built differently, the effect is slightly different in each amplifier / loudspeaker / loudspeaker cable combination, but there is almost always an audible improvement.

Suitable for use with all types of amplifiers (Class A, A/B, and D) and all types of loudspeakers and cables.

They are not compatible with active loudspeakers.

The connected-fidelity™ RF Blocker is based on sound electronics principles. There is no ‘Angel Dust’ used in this product!

The RF Blocker is designed to audiophile standards

High quality electrical components are housed in a die-cast aluminium box acting as a Faraday cage ensuring no further RF interference is picked up to enter the audio chain.

The short attaching cables are multi-strand OFC copper, connectors are gold plated.

Your audio system

RF Blocker Spades

The RF Blocker’s will work to a lesser or greater degree with all audio systems and the benefits will carry through to any further upgrades of amplifier or speakers or cables you may make in the future.

If you are bi-wiring, you can use two pairs of RF Blockers to maximize the benefits but one pair will also make an improvement.

Experiment fitted to the bass terminals, then on the mid/treble and decide which option sounds best to your ears.

They normally find it’s the critical 1-5,000Hz range (mid-range) that makes the most audible difference, but it is worth experimenting.

It is possible to fit at the amplifier end of course.

Fitting instructions

  • Fit and forget – then enjoy the music.

RF Blocker Specifications

  • Wide band radio interference filtering for clearer audio
  • Designed and made to audiophile standards
  • Die-cast metal body
  • Choice of three connection options


  • This is not a mains or electrical power product. DO NOT CONNECT TO MAINS POWER.

Additional information

Connector type

Banana plug, Bare Wire, Spade


Connected Fidelity

Connected Fidelity Michael Osborn, designer, engineer, manufacturer, and lifelong music lover, has been working in the Hi-Fi industry for over 30 years. He initially designed and launched the Astin Trew brand audio electronics ranges, then moved into audio products Distribution, introducing brands such as Astell n Kern and Hana cartridges to the UK during his long and successful career in the audio industry. As an inveterate designer and maker, Michael has throughout his career continued to design and develop products for his own use when nothing in the market fitted his sense of what makes music in the home sound so good and ended up selling these products to fellow audiophiles in an ad-hoc way mostly through word of mouth. He has also helped fellow audiophiles develop products they were working on and will be launching some of these through connected-fidelity™ when they fulfil a need in the market and pass the connected-fidelity™ sound-quality seal of approval!

So, connected-fidelity™ is the brand that now offers these fine products to everyone.

Connected-fidelity ™ products all do one thing.

They make the experience of listening to recorded or streamed music in the home more enjoyable by bringing you closer to the actual music.

This might seem like a simple and obvious statement, but the reality is not easy to achieve.

All the products have taken many long hours of development to get right, both sound-wise and price-wise, numerous development samples, research into materials and processes, long hours of comparison listening tests.

Connected-fidelity ™ is not shy about talking about the how and why.

Clearly there are some processing and manufacturing ‘secrets’ that are not disclosed for commercial reasons but are as open as possible about how the products are made – and the manufacture is in the UK.

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