[butisaidsudo]

You'd think so, but recordings are usually mixed to sound good out in the wide world. The most famous mixing monitors are famous for sounding awful.(https://www.soundonsound.com/reviews/yamaha-ns10-story) The thinking there is if you can make the song sound good on those monitors, it'll sound good anywhere.

A lot of songs are mixed with less bass than ideal, because the engineer knows that everyone and their grandma has that bass boost button permanently down on their stereo. Or people are using beats headphones that crank the low end.

The ideal mix also changes over time. Part of that is fashion. Every period has its own ideal sound. But another part is the equipment the average listener has.

Ever have a beater car with a terrible stereo? Music from the 60s will still sound great because it was mixed to sound good on transistor radios. You can hear the bass guitar even though there's no low end on your setup. Anyone who had a K car in the 90s has a love for CCR. That's a fact.

In previous decades music was mixed to sound good on wood encased speakers, which have their own resonance characteristics. For modern music, you assume plastic. You also have to assume that a large portion of listeners are going to be using apple earbuds, or some other cheap earbud.

When working on a mix, you usually have a few different speakers to choose from in the studio. But the final test is always how it sounds in a car.

[colanderman]

I agree with everything you said, but were Apple compensating for that, I'd expect them to use a curve weighted to crappy studio monitors/Beats headphones/etc.

A couple other commenters noted that perception-weighted curves vary with total SPL; louder sounds sound different. I had never thought about that before but that makes sense to me, that Apple would apply a dynamic adjustment that studios can't.

[butisaidsudo]

Oh, that's an excellent point too! Bass boost and loudness buttons on stereos are meant to give you a way to make music sound the same at a lower volume, but most people just set it and forget it.

With fully digital players, I guess there's no reason to not have dynamic EQs that adjust along with the volume. I'd think you'd see this more often, but I guess even basic EQs aren't available most of the time, so it's just not a feature that most people would care about.