Fidelity Audio No Noise Z - Speaker RFI Purifier/Filter

[Fidelity Audio No Noise Z - speaker noise filter]

Noise trap

[Italian version here]

Product name: No Noise Z (NNZ) - Speaker RFI Purifier/Filter
Manufacturer: Fidelity Audio - UK
Cost: 199 UKP/pair (Currency conversion)
Reviewer: Richard Varey - TNT New Zealand
Reviewed: October, 2015


The NN Z Speaker Filter connects across speaker terminals. It filters out high frequency interference that is picked up via the speaker cable and internal speaker wiring, and is created by speaker crossover coils. The NN Z is designed to help deliver a three-dimensional soundstage image and a blacker background with a much lower noise floor.

Further, the manufacturer suggests users can expect wider stereo imaging, better instrument separation, and less midrange muddle - overall better tonality in the speaker performance. But they also note that systems react differently to filters. Untreated, they have different amounts of noise and at different frequencies. The more noise present in the system, the bigger the impact the filter will have. To realise full effect from the filters, they advise a burn in period of at least 100 hours.

Each NN Z is a 53mm x 37mm x 23mm black box fitted with RFI / EMI absorbing technology using high quality audio grade parts and high quality Silver plated Oxygen-free Copper cable (OFCC) with PTFE insulation. The unit has 6 poles of articulation ranging from 60 Hz to 5.4 Mhz. The PCB is damped to eliminate vibration of components that may affect performance.

You can connect the NN Z to the 4mm binding posts at the rear of your speakers with the Gold-plated Beryllium Copper piggy-back bananas or 8.5 mm spades, or connect at the amplifier's speaker terminals.

In use

I received a pair of filters for review direct from the manufacturer with no retail packaging or documentation, so went back to the website to find out more. I was able to very easily install them in 2 minutes at the end of May, and my review is being written mid September, after several weeks of the units being in place and largely forgotten about.

You won't find any hype from the Company. This is not a glitz or glamour product. There is no arty “value-adding” packaging to make the product more appealing with glossy presentation - and thus more costly, yet tossed in the trash (think Apple, iFi, certain expensive cables and interconnects). It was designed to be neither seen nor heard.

It's one of those easy products - fitted in seconds without the need for tools or (sometimes expensive) additional parts, and out of sight - thus easily forgotten (apologies to Brent at Fidelity Audio for the delay in putting this review together - I did forget about these units as I enjoyed my super-engaging musical presentation)! There is no need for a user manual - the operating instructions are simple - attach and listen to music!


[Fidelity Audio No Noise Z - speaker noise filter]

How do they perform? I put my head as close to the speaker driver as I could without touching - there was no audible difference between my amplifier switched on or off. Any interference is eliminated. Perhaps there is even a sense of an enlarged and more dynamic soundstage, subtle yet discernable.

This is literally a “black box” - perhaps even the audio equivalent of a black hole - no noise! I think these filters have got to be one of the easiest upgrades I have made to my system (there have been many!). I recommend you give your music listening experience a boost and try them.

Thanks to Brent at Fidelity Audio, Doncaster, South Yorkshire, UK.

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