> Third, audio quality is deeply subjective, and what sounds good to my ears may sound like total garbage to yours.

Interesting article (audio processing should be a standard OS feature), but I wish we'd stop doing this. Speakers were never subjective (unlike earphones), they’re supposed to be flat – “equalised”. At least if you want to hear the thing as it was mastered.

I think it just hurts consumers in the end, as it validates snake oil in the form of various ”enhancements”, like image processing on TVs. It makes stuff really hard to compare and much easier to sell shitty hardware.

Not that I’m opposed to improving shitty hardware with software, – quite the contrary – it’s just the murky subjectivity that irks me.

> Speakers were never subjective (unlike earphones)

I don't think this has been true in my lifetime, at least. Some brands being known for "warmth" vs "brightness" is ages old, before the idea of audiophile earbuds was even a thing. At the extreme end, you can go back at least 40 years to see people with dedicated sub outputs and massively-oversized non-flat subwoofer setups.

No speakers have flat frequency response. If that's the target (it usually isn't[1] even with very elaborate systems that include a great deal of DSP grunt, in my experience), then they all miss -- every single one of them misses.

All speakers have resonances that add to the sound in ways that frequency response, alone, does not measure. All speakers also have imperfect dynamic response. All speakers have imperfect impedances, which can matter quite a lot to the power amplifier that drives them. All speakers have non-linear phase response. All speakers have different dispersion characteristics.

All speakers then operate within acoustic spaces (like a room in a house) that introduce even more variables.

[1]: https://professionalsupport.dolby.com/s/article/Dolby-Atmos-...

Speakers, at least the great majority of them, are not flat. Can you not hear differences between speakers? Studio monitors typically aim for a flat response, but most barely make an acceptable approximation. And then we're not even discussing phone and tv speakers or the fact that a flat response for pure tones doesn't necessarily translate to one for complex sounds.

I have heard that audio engineer's don't necessarily master to a flat EQ because such a small section of listeners are listening with a flat EQ. Most are using car speakers, airpods, etc so they master it based on those expectations.

The definition of sound quality tends to change between people.

My definition is pretty much the same as yours here, but I know quite a few people who hate listening to music on anything with a relatively flat frequency response.

Why would speakers be any different than earphones? Botu are subjective ; I personally hate flat eq. I've listened to numerous products, some worth thousands of dollars, and I'll always take some sort of slight bass and treble boost over flat eq. I'll even take a big bass boost over no bass boost at all.