Review: Stillpoints ERS Tweak

Category: Accessories

I must admit a fondness for trying almost every tweak that comes down the pike. Going in, many make sense and many do not. I remember being very suspicious of any difference a power cord could make, as it just didn’t make sense. After all, if your house was wired with romex, how could the last leg of the chain make a difference? Well, we all found that they do make a difference, and some to a larger degree. For some of the same reasons, the Stillpoints ERS also comes through with flying colors.

From the Stillpoints website:
The core of ers is made of a blend of carbon fibers of various lengths and sizes. Using a proprietary method, these fibers are coated with metals, such as nickel. These fibers absorb, reflect and diffuse RFI/EMI. ERS has on average about 66 db noise reduction in it's 10meg to 17 gig range. This is all that we can claim, due to its defense restrictions. (the product was previously defense department classified) The exterior is laminated with a polyester textile on both sides to make the material easier to handle and use.

Specifically, ERS rejects and absorbs EMI and RFI interference and it does so very efficiently. I say this because it doesn’t take full coverage to make a very audible improvement. ERS comes in 8 x10” sheets and by all reports, does the best job if attached internally to your equipments case. I noticed an immediate improvement just laying one sheet on the top of both my CD player and preamp. I am a big fan of EMI/RFI removal, as many well designed tweaks designed to do this will improve your sound top to bottom with no side effects. The Z-sleeves are one of these products and the Stillpoints ERS mimics the improvement you get with the Z-sleeves. I am told that ERS is one of the internal components of the Z-sleeve.

My first introduction to RFI reduction came in 1982, long before any commercial product was made available for audiophiles. I was invited to a listening session at an Oberlin College professor’s house in Oberlin, Ohio. He had modified some older Scott tube equipment and was showing it off with some Klipshorn LaScalla’s. I noticed some little red rings that his interconnects both passed through and were hanging on. He gave me a few to take home and lo and behold, an improvement. These were nothing more than ferrite choke cores and the predecessor to products like TDK’s noise filters and “Blockers”. They actually did a better job with none of the sonic disadvantages found in the later products. The other non-RFI related tweak he was utilizing was large copper Frankenstein-type throw switches in his speaker lines. This was wired so that he could change phase for each and every song in his collection. His albums were cataloged and marked according to phase – as well as individual songs on each album. I didn’t read about phase issues in the audiophile community for at least another ten years. This guy was ahead of his time!

Most of us have bought in to the idea that EMI and RFI are detrimental to our entire audio chain. This is evidenced by the many power conditioners that are now sold to eliminate the same. The problem is that these only solve the RFI interference that exists in the power line. RFI is present in every part of your audio chain. The longer your speaker wires are, the worse the problem can become. Think of your wires as an antenna.
According to Stillpoints, digital gear not only is more affected by EMI/RFI but actually produces RFI internally! For this reason, they feel the ERS works even better on digital gear.

This reminds me of a RFI toy that I had as a child. Many of you may remember the “radio rocket” which was nothing more than a transistor, potentiometer, and earphone. You would find ANY metal, attach the alligator clip, and you had a radio. Any metal object contained enough RFI to be an antenna. We would use fences, garage door tracks, and lamp cords – anything metal worked. This was a great toy back in the 60’s and proves that RFI is everywhere. Think of the increase of it since the 1960’s!

As we have found with any tweak, properly designed products work great, the ones that aren’t can actually cause sonic degradation. Stillpoints ERS work, and from a price standpoint, are a steal. These sheets improve the sound across the board and do so in a similar manner to any well-designed EMI/RFI filtration product. This includes removing a level of grain that you previously didn’t realize was there. Inner detail and focus, and transparency improve dramatically. Dramatic is a description that is easy to use considering that these sheets are only $20 a piece, and $29 for a pre-glued sheet. I also gained an improvement in soundstage width. I treated my entire system with four sheets and actually went overboard on the CD player. This is the efficiency I spoke of earlier. There is an improvement with just one sheet on the inside top of you components. You gain slightly more using it on the bottom inside panel as well. Mounting it on the sides is overkill and a waste of material. I ended up covering only the power supply in my Aesthetix Calypso, and the top inside panel of my Magnepan 3.6 crossovers. I also cut small strips and used them on the internal wire runs to and from the power supplies. This product is very easy to use, cut and install.

I’ve tried to make a case for EMI and RFI having a detrimental effect more than just your AC line. Stillpoints ERS is an inexpensive and effective solution to this problem. The Z-sleeves are another highly-recommended device on my list.

As with any tweak, ERS does require some experimentation. I read all the printed reviews to get a starting point for my use. I did initially mount a sheet above the analog boards in my CD player and after 6 hours, removed it. Although there was an improvement using it there, the highs were slightly too prevalent with it in place. In some analog circuits, the presence of EMI/RFI is tuned into the frequency response of the device. ERS can effect of the amplitude of the high frequency and/or the low frequency extremes resulting in a less than desirable balance.

Spend $20 to $100 and prepare to have some fun while improving your sound.

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Great review,ive been thinking of trying ERS for a couple months now,ill probably be getting some soon,and will report back.Thanks for all the info !
I just started experimenting with the ERS sheets this weekend. In this short amount of time I've discovered it works best over transformers in all equipment. I've also used cloth to segregate the power supply from the processor in my DAC, a sheet over the power supply section of DAC was also usefull. I've also tried them in various other locations on all my equipment.
Thus far I've found ERS cloth to be a subtle improvement, slightly more smoothness and quietness which results in more inner detail and focus. However, I've found that too much and/or improperly placed sheets can take away texture and air sort of making things sound lifeless. One needs to be very careful with these!
i had used these when they first came out which was a big hit with tact audio users in their digtial amps. what i found out and was supported by a company that did all the work on upgrading my equipment is that these sheets actually act like a treble tone control, what they do is reduce high frequency's which then makes you seem that your are getting better bass. because of this it lets you turn up the volume on your gear more. go back to you beginning days when you had a reciever or integrated amp with tone controls. treble was boosted as well as bass. when you thought you were running out of power you would turn down the treble so it could play slightly louder . this was removing high frequency's which sounded bad at really loud levels. when my gear was upgraded i could actually take a small piece and place it on the interconnect and hear the highs just get sucked away. the problem with even putting them on transformers is that it effects everything inside your piece of audio gear. i do not use them anymore for this reason. try rf clamps on your power cords and interconnects to see which leaves the life into the music. iwill tell you were they work is placed on your computer module in your car. it removes the rfi and causes the computer not to work as hard and actually you will notice a improvement in the cars idle as well as a improvemnt in fuel economy. just put a piece about 1/4 to 1/3 the size of the computer module over the center of it. worked great in the last 2 cars i had.


There is no question that used either in the wrong places, or in too much quantity that they will effect the balance. I isolated the power transformers and power lines within the CD player and preamp with very good results. I did get an increase in treble when using sheets in close proximity to the analoge section in the CD player and had to remove these. This is why I said experimentation was the key. When using them on the inside cover of the CD player, it was most definately an improvement, with no loss of high end and overall better inner detail and image width. There is no difference in bass response on my system. Again, a cheap tweak at $20 needed to cover just the inside lid of a CD player.
I am in a quandary. Years ago I bought four sheets of ERS paper. On my Reimyo 300B amp's transformer, I initially cut a 3 by 2 inch piece. It was awful. I cut it in half and tried again. This went on until the piece was a one half inch square, but I much preferred none. I put all of the ERS in a cabinet. But still the sound was dull and had no dynamics. I sold all the ERS.

Five year later I got the Z-sleaves Ultima and put it on my main pc from the wall. It sounded much improved even though it used ERS within. How could this be? Answer, I really don't know. Is it keeping the ERS off the circuit; is it the metal in the Z- sleaves cone, is it purely where I used ERs?
Tbg, difficult to be sure about the ERS in the new improved Z Sleeves. Is it possible that the Z Sleeves would actually sound better if the ERS was removed? In other words, the improved Z Sleeves have other innovations besides the ERS, is that true? Everything is relative - a. einstein