InvisibleInk
Headphoneus Supremus
I had experience with Fir Audio, M5, M4 and new VxV, heard empire ears phantoms, Lx and zeus.
What I can say is EE brand is a very flavorful tuning they like to impress you and create wow factor. They are very technically strong contenders and lot of fun to listen. Not something I would use for reference or careful analysis iem, but it has strong capabilities and unique in its own.
Fir Audio is a brand similar to 64a because Bogdan the ceo is the brother of Vitaly the ceo of 64a, so I think they have split and this why we see fir to be so close in the concept.
Though they quite very different when it comes to tuning presentation.
64a is more cleaner, precise and nuanced. When you do careful close a/b you will see that 64a has an edge on treble, sub bass, resolution, very nuanced details like speed and transitions between notes and decays. They can be very phenomenal on Fourté and Trio.
Fir audio is more toward on the stage artists, cause when you listen to M5 you feel the sound like its been played from a speaker setup on the stage! It doesn't reach deep or as black in the background presentation. With M5 you hear the atmosphere the air and a very open sound like. It is a good iem very strong craftsman built and the Rcx conector is rock solide it does stand for what they say.
But me I love EDM music and Tia Fourté owns M5 and M4 eyes closed. It has those very fine thin and very lucid effects in the tuning that I have yet felt in any other iem. Its made so sensible and true to its source that fourté is a true chameleon. You can fine tune it with cables and dap, it responds instantly to any changes in the audio path, with fourté you can understand how each cable sounds with its all different strands and alloys that have been used.
You can even compare cable soldering quality lol its that sharp and precised.
It is the reason why I call Tia Fourté a world class iem its extremely strong and nuanced sound.
Hope that helps and I am sorry for your wallet
Three thousand, six hundred dollars...