Click this sentence for IEMs/TWS earbuds and headphones with PC gaming, squig.link, AutoEQ, parametric EQ.

Click this sentence for using squig.link, parametric EQ, etc. to gauge future purchases.

Look into squig.link and use the AutoEQ feature there, you can compare graphs, easily parametric EQ to a specific target, etc.

Here's Super* Review using the new AutoEQ feature of his squig.link site: https://www.youtube.com/watch?v=RWzBw3XBn8c&t=332s

Or actually here's Timmy from Gizaudio explaining it too: https://www.youtube.com/watch?v=gpQalW_bjLQ

Check /r/oratory1990 for the preset parametric EQ list (mainly for headphones but there's some IEMs there): https://www.reddit.com/r/oratory1990/wiki/index/list_of_presets

You can do (parametric) EQ with $8 Neutron Music Player or UAPP on Android. If on PC, the free (Peace) Equalizer APO. There are free apps on Android(/Apple) that can also do a good enough job, but most of them have those graphics sliders instead of parametric or just plug the numbers in EQ. EQ can also be used to help with channel or ear imbalances.

There's also the free Wavelet app that has the AutoEQ available now. And other free apps for more simple graphic sliders EQ, etc.