cdacosta
Headphoneus Supremus
I am glad what you have tried has improved your system and you like it. I am also glad you experienced it the way you did and posted it. Lets try and improve on it...Progression notes with Rochelle salt hack recommended by @cdacosta
First few days I tried it behind AC wall faceplates. Initially I had mixed results, until shifting some things around. Trying it behind two auxiliary AC power cord faceplates on 2 other walls of the room (lamp, space heater and modem). I followed Chris (CDA)'s recipe down to the letter. Although being without a scale I got the same recommended salt and multi-pack of bags, used the same amounts, and eyeballed to compare to his photos in this post several times and I can say with certainty this is around 95% identical to his recommended amounts and precise placements he used behind the AC faceplates.
My system went from highly resolving and extended though somewhat bright - to even more resolving and with hyper extended highs that were just too fatiguing. After letting it settle for a day, still no change so I removed the larger bags from both of the "hot" line which is on the right when facing towards the faceplates, leaving only the bags installed in front of "ground" filtering behind the faceplates. One may surmise this hack with AC faceplates is like "HOT = TREBLE; GROUND = BASS", to some extent. At this point my system sounded better than the initial attempt, but something was off. It came down to my unique setup having multi-stage AC power filtering with a series of both Flux-50 knockoff from Aliexpress + iFi Audio Ground Defender before my multi-thousand $$ Furman central AC power conditioner PLUS the full recommended AC faceplate tweak from Chris was turning my system into a detail monster. So after removing both AC filters with just the very esteemed 15-core Valhalla AC cable into my power conditioner and already removing the taller hot side Rochelle filtering behind both AC faceplates leaving only the smaller Rochelle filtering the ground side on the left of the AC faceplate - this was the magic ticket. I also added Rochelle salt bags behind the main AC faceplate powering the main system (on both sides IIRC). Now sounding more neutral, analog and natural than before I started!
I would say this tweak is system-dependent - especially if you already have hefty / multi-stage AC power filtering, go easy on the larger bag on the "hot" / right side if any.
Today onto the ground box cable component side. Initially it was hard to notice a difference, but after installing at least 3, things started to sound even more lifelike and with more relaxed highs Most of my GB cables use 2 wire runs in parallel so each GB got 2 salt bags on the opposite end. Now with 10 medium-small bags wrapped like short cigarettes then wrapped parallel to the recommended copper ground box cables on various component sides - things are sounding quite stunning indeed! That along with a few small bags on top of various wall-warts in the system and one more and on the hot side of another ancillary AC faceplate (on the front only due to it being inaccessible for removal in tight quarters) - what I am hearing now friends, is making my (+/-) $7K sound system best most any other system I've heard under $20K at any CanJam I've been to! Quite unbeatable and enough to make your hair stand up! I'd describe it as that X-factor or 6th element. 4D sound, impressive detail, FR & resolution, uncanny realism and an unquantifiable factor. A lot of this amazing sound is also thanks to the Lhy OCK-2 external clock and my special mesh faraday fabric shielding I have on the walls around the desk of my system (mainly), and also iFi DC blocker & Flux-50 into the DI-20 DDC and various iFi DC blockers, not to mention the 4x custom +1 premade ground boxes I'm using so far. So good I'm overwhelmed and will let this sit before adding any more to the system.
The pics I provided are deceiving. How much you use makes a big difference as you already experienced. Sounds kind of almost not believable a small amount of Rochelle salt or anything away from the system attached in the middle of 1000'+ of wiring would do anything. But it does as you have experienced, even at only 2 or few locations. This is going to sound absurd, but what you are hearing is only part of what is available to you. There is still several or more levels of noise that is masking information still available to you. To the extent will lift your system beyond what you think is possible on good recordings.
So lets recap what we are trying to accomplish with absorbing EMI from the AC wiring. Should not matter what your AC line filtration or conditioning is or have. Your AC wiring in your home is picking up high frequency noise/EMI and accumulating it. This high frequency noise masks information that is available in the recording, which is limiting the amount of information your system has to decode. The less high frequency noise that reaches your system, the more information your system has to decode. Basically the more noise you remove, the more you hear, this is especially true of ultra fine detail.
What you experienced is exactly what I experienced when first experimented with this tweak. The Hot side in the AC wiring is the key for bringing out more, and more, and more detail until ultra fine nuances are heard. The ground is to control the weight or body of the presentation and balance out the overall tonal presentation. Ground side does remove some of the EMI but is a small fraction compared to the Hot side. As noted in my original DIY post, if leans to much toward neutral or bright, cut back on the amount of Rochelle salt on Hot side. If system presentation is too warm cut back on the salt in the ground wrap. If I were to guess, instead of 1 gram you used closer to 3 grams. When eyeballing, looks close to the same amount in a small zip lock bag. Trust me on this, I have spent many hours experimenting with this.
On those same outlets try 1/2 of what you were using, then listen. If still leaning toward neutral, back off a tad more until system tonally is the same. Precision scale obviously is handy for this. Key to this tweak and tuning is to install both wraps at a junction, then listen to your system. If you did install the 1 gram at Hot and .5 on ground there should not be a tonal shift. Or at best so slight you are not sure if there was a shift. So you can understand, install at a light switch plate or outlet not used by your system. This will be easy to test before and after by just placing the wall plate on or taking it off. The wall plate will stay in place without it being screwed in. Once you understand how well/effective the Rochelle salt is, you will understand less is better. Once you get the amount to use in wraps down, you will feel comfortable and want to treat "all" junctions along your AC wiring in the home. Because as you treat more junctions, your system becomes more and more resolving. You will hear the changes in your system with even junctions along the AC wiring in breaker circuits other than your systems.
The purpose of this post is to hopefully explain more clearly, or in a different way how to tune and go about judging installs. The performance gains from 2-4 partial installs is just a little taste of what is available to you.