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Shielding components from EMI/RFI... Help please

A recent experiment with a product designed to reduce EMI/RFI left me curious about other ways to reduce EMI/RFI in my system. In the past ten days, I've stepped onto a slippery slope, at the bottom of which is surely some kind of insanity...

I've been experimenting with copper plates in an effort to absorb, deflect, diffract, and block EMI/RFI. I've tried copper plates under components, on top of components, and inside components.

This is the point where you tell me I don't know what I'm doing and I'm likely to short circuit something and/or electrocute myself. Consider me duly warned. This is also the point where you tell me to get some balanced interconnects, or at least to get some shielded interconnects for Chrissake. Consider me duly informed. Moving on...

I'm hoping you can help me make the most of this experiment, and help me avoid killing a component or myself. My strategy so far has been to:

1. Place copper plates at locations that generate a lot of EMI/RFI, e.g., components with switching mode power supplies or high frequency clocks. The system has a total of 3 SMPS and 3 clocks.

2. Place copper plates at locations that are vulnerable to EMI/RFI, e.g., under the amp, near the transformer.

3. Place copper plates inside noisy components -- in particular, my Meridian G68 preamp/processor. I've begun to build 2 partial Faraday cages, one for the SMPS, and one for the analog output stage.

4. Ground the copper plates either to the component chassis (when plates are used inside a component) or to an independent ground point (when plates are used above/below a component).

Has anyone tried this sort of thing?

Bryon
bryoncunningham

Showing 3 responses by sabai

sabai
2,027 posts
 
Bryon,
You might want to read my new thread on Synergistic Research Mini Power Couplers. It is related to EMF protection.
sabai
2,027 posts
 
Bryon,
I am an inveterate tweaker. Neodymium magnets are among my favorite tweaks. I place them on or under components near transformers to draw off EMFs. The effect can be to increase the focus of instruments and voices and to provide a clearer sound than without the magnets in place.

Yesterday I got a big surprise. I went around my system with a bundle of 4 neodymium magnets to see if I could feel any strong magnetic fields coming off of components or cables. I arrived at a Synergistic Research MPC. Lo and behold I felt a very strong magnetic field when the magnets came close to the MPC. I guess this should have been no surprise but I had just never got around to doing this kind of system test before. There was a spot on the back of the MPC where the magnets wanted to be. So I went through my system and let the magnets find their place on the back of 5 MPCs in my system -- mostly Galileo.

I flipped my system breaker and when the first sounds came through my speakers I knew the magnets were making a real difference in the sound. Instruments and voices became more focussed as well as smoother. The soundstage became a tad more recessed but also somewhat deeper. The sound is now softer, more pleasing and more musical to my ears -- without any loss of resolution. I am using all of my reference CDs to test this today and the results are uniformly good.
sabai
2,027 posts
 
Hi Bryon,
My last post was not allowed. Probably because I referred to another audio site that has about 200 posts about the use of neodymium magnets. You have to experiment with them to find where the magnetic fields are emanating from in your system -- typically transformers in components and AC adapters. Then you let the magnets guide you to the "sweet spot". I use 1/8" x 1/2" neodymium magnets in bundles.

They make a difference because they draw off the magnetic fields from the transformers. You place them on the outside of components and AC adapters. This has worked very well for me with SR MPCs that have a strong magnetic field.
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