That's the 'device with an imperfect response curve', I assume.

In fairness, the readme does state:

> A good microphone is needed, with a wide frequency range and preferably with a flat frequency response.

By 'preferably' I assume it's implied that it can curve-fit (whatever's needed, I know next to nothing about this) to a non-flat microphone response, as long as it's known, but if it's flat then no need.

If it's unknown (and non-flat or assumed non-flat because it's cheap and doesn't make any claims about it) then that's the real problem, no point trying to do anything because it's like trying to construct a level floor with a shoelace for a spirit level.

i always wondered, is it possible to take a cheaper mic or iems and "flatten" them via an eq, to perform nearly as well as professional gear that's 3x the price?

i just picked up a pair of KZ AS06 iems [1] and my listening preference is U shaped (which is how these are dialed in out of the box), but i imagine with quality hardware and e.g. 3+ dedicated, drivers it should be possible to flatten them out in an eq.

[1] https://old.reddit.com/r/headphones/comments/eqpsen/kz_as06_...

Yes, to an extent, and this is frequently done to great effect. However frequency response isn't everything, there's also e.g. group delay, off axis response, and harmonic distortion. In particular, boosting response in areas a speaker is deficient often causes a huge increase in distortion, so you have to balance.

Yes, but no, but yes.

AutoEq (https://github.com/jaakkopasanen/AutoEq/) does something like this so... yes?

But targets various HRTF curves which aren't neutral or flat, and they usually aim for a Harman target of sorts, so no...

But there are some neutral-sounding curves that seek to just emulate pinna gain, so they have a ~3KHz peak which is required to 'emulate' the natural resonance of your ear, which you don't get naturally when you jam a driver all the way into it.

There's no AutoEq preset for the AS06s. Here's a representative sample targeting the 2019 Harman in-ear target for the KZ AS10s for funsies though: https://github.com/jaakkopasanen/AutoEq/tree/master/results/...

the AS10 and AS06 curves look quite similar, so might work, thanks!

https://www.reddit.com/r/headphones/comments/afsro3/review_o...

Commercial systems that do this kind of room correction generally have a limited range of recommended microphones, and the more expensive (and hopefully better) ones will have the microphone calibrated and factored into the room correction - for example, Anthem's Room Correction (ARC) ships mics that have a serial number. You plug that into the ARC software, it looks up the factory profile of that specific mic, as it was recorded at build time, and weights the calibration for it.

Here's a measurement standard mic:

https://earthworksaudio.com/measurement-microphones/m23/

And what would be the "80% of performance for 20% of the price" equivalent of it ?

Minidsp umik-1.