Almost 8 decades......I am 76.
I did not invent this thang.....just tweaked the design for hours. Enacom made the first version of this thing in the 90s. Then Walker Audio made a version and then updated it later (later versions were something like $650 a pair), then Merlin made some that came with their $10K speakers. All the above no longer available. Stein Music makes the "Speaker Match" that sell for $700 and a super version that sells for $1800........and you see what mine sell for. By the way, a second set will cost you a big $100.....this includes a free pair of Ground Enhancers with each set. My versions use multiple tiny surface mount resistors in parallel and a modified small film cap. The end of the surface mount resistor pile is soldered directly to the modified caps tinned end. The ground wire is soldered directly to the cap body on the other side as well. Very delicate work....and the most transparent parts I know of. The wire itself is the connector......so the shortest signal path I can do. All constrain relieved in a hard thick paper tube (fireworks tube). Every single thing you do affects the sound. So, all resistors, capacitors, solder, wire, connectors, damping, etc. affect the sound of everything you do and these things are no exception.
So what the heck is it and how does it work? It is simply an RC filter. It is a single pole filter that operates above 200K (yes, it is measureable). So why would it matter if noise enters your speaker above that frequency? I am not an electron. I cannot tell you how much better it must feel when it does not have those nasty high frequencies along for the ride....he he. All I can do is describe what it does to the sound. There is only one person who returned these things stating he could not hear a difference. I returned his money along with the shipping charge. All he paid was the $8 to mail them back. And immediately I sent them to someone else who loves them.
I had a new experience with these things about 10 days ago. I very recently made a new open baffle speaker (to be described and shown on my website soon) and I am bi wiring it. I had a Music Purifier on the Planar mid/tweet but did not have one on the two 12 inch woofers. The woofers have a 2mh coil on them so they are starting to roll off the highs at around 300hz........so I did not expect much difference when adding a Music Purifier right before the coils. I put the second pair on the woofer wire and OMG.....I about fell off the chair. The purity and ambience went into another level. So, if you are bi wiring or bi amping you REALLY want two pairs.......and more if tri or quad amping.
What is so cool is that these are super cheap and super universal. They work on every kind of speaker and at any price point. So a $2k system will sound better and a two million dollar system will sound better. As long as you have speaker wire that act like antenna....then you have noise going into the speaker. If you have speaker cables that already have filters built in.....like some of the Transparent and MIT speaker cables do....or some ground/shield biased wires like the expensive Audioquest wires, then you might not get any benefit from these things. But that is about 1% of audiophiles have those wires......so that leaves at least 250,000 audiophiles worldwide that could benefit from these things and pretty much all of them can afford $125.
Happy listening! Loving and enjoying this very moment is the key to happiness.