The Black Rhodium Blog

Magnetic Wave Absorbers and how they are designed to stop vibrations and noise generated from unused RCA inputs in your system.

 - By Graham Nalty, founder and owner of Black Rhodium

Magnetic Wave Absorbers work, and they work very effectively.

To test these, I constructed a number of shorted RCA plugs and plugged than into all unused RCA inputs in an amplifier. Then I replaced them with the Oyaide MWA-RC inserts. The difference was positive and quite audible. They certainly work better than shorted RCA plugs, which are, of course, better than nothing.

Here is some technical information on Oyaide MWA-RC.

It has long been recognised that by applying shorting links to unused sockets in amplifiers and other audio electronics, the distortion effects from Radio Frequency Interference (RFI) entering an amplifier via open sockets can be reduced. In strong fields of interference this shorting link can act as a low impedance aerial.


With the growing popularity of digital electronics such as computers and iPhones, the need to protect sensitive audio circuits from high frequency interference becomes more urgent.
Engineers at Oyaide in Japan have developed MWA-RC specially to cover RCA sockets to prevent magnetic noise and dust by attaching them to unused RCA sockets on the equipment.

The Key features of the Oyaide MWA-RC are:

⦁ MWA-RCs are easy to fit – simply place them on any unused RCA socket
⦁ Manufactured from polypropylene which dampens the tiny vibrations found in the unused contacts
⦁ The use of 1mm thick MWA absorbers on the cap reduces noise generated from the contacts. This material is called SENDUST which Oyaide have applied from a technology developed in Japan. By processing it into a flat shape this has increased the absorbing property against Electric Magnetic Waves
⦁ The cap also prevents dust build up.
⦁ Using the MWA-RC on multiple sockets can make the improvements much greater.
⦁ MWAs are suitable for both input and output sockets

The improvements to your sound quality from using Oyaide MWA can be very satisfying.

⦁ With MWAs placed in all open sockets, the improvement in sound quality can be very obvious
⦁ Your music loses stridency
⦁ Climaxes in sound are more natural, without the feeling of being ‘forced’ or loud
⦁ The music flows are more natural, allowing you to absorb yourself in the music rather than be distracted during listening
⦁ The level of improvement can be very far more effective than upgrading of hardware which would be very much more expensive
⦁ The benefits can be observed quickly and easily by simply lacing MWAs in the unused RCA sockets