I own an Etymotic ER4-SR , and a Sony WF-1000XM4 ... I apply AutoEQ
https://github.com/jaakkopasanen/AutoEq/ when I listen to both of them so that I get as close to the same frequency response as possible to both of them, normally the Sony wireless earbuds has a significant and broad peak at the lower mids which makes them subjectively worser to listen to... Now with the equalization, I get almost the same sound from my wired BA IEMs , as well as my wireless noise cancelling earbuds
But, there is still a difference that equalization cannot fix, and that is data compression... While some of it can be down to the differences between the balanced armatures in my wired IEMs and the dynamic drivers in the wireless earbuds, I think that the degradation of the sound signal is playing a big role
Being a child of the 90's, the best way I can describe it is like the difference between hearing a CD player and a Game Boy Advance , only much subtler
Listening to wired earphones is technically and physically the de facto standard, and when I compare my Etymotics to Sony earbuds (both with equalization) , all the sound especially the higher frequencies sound more 'physical' and realistic, and also the bass feels like it hits deeper ... The frequency response is enforced by the AutoEQ equalization , but the wireless earbuds are still lacking a certain quality which makes the sound feel flat and distant, I just don't feel like I am 'right there' in the sound...
The word I want to use to describe it is 'clarity' , but this is the best analogy that I can think of for now: With the re-recording of analog audio and photocopying of analog pictures, you lose clarity of your original material by means that can be described by some physical parameter such as muffling from the loss of high frequency sound and bluriness from the loss of spatial resolution in the picture....
But with digital sound and pictures, you are using psycho-perceptual calculations in your data compression and the loss in clarity is harder to express, we have one word to describe this loss in all forms of digital media: Artifacting
The very nature of the wireless technology in the earbuds is a compromise to the very function of sound reproducibility ... I can't wait until the day when they can wirelessly send uncompressed digital audio
However, the lack of a cable and its associated microphonics, and more importantly not having to hear the rumbling from both my own body(heartbeat, muscle movement, etc etc) and my surroundings(cars outside my apartment, the hum of A/C units, etc etc), makes just turning on the noise cancelling a positive experience in its own right
