Start with an Android phone with sufficient storage capability and a decent DAC/headphone amplifier. Built-in is great; otherwise, find something that works and doesn’t suck up too much power.

Add IEMs of choice, for less than $50, or cans that are reasonably efficient. It stops being so portable if you have 800g cans and a 500g battery-powered amp to drive them.

Install F-Droid, and use that to install Vanilla Music and RootlessJamesDSP.

Configure Vanilla Music to point to your music data.

Use ADB to enable RootlessJamesDSP (it needs 2-3 android system permissions).

Download convolution equalization for your IEMs or cans. https://autoeq.app is an acceptable and very convenient source. If Oratory1990 covers your equipment ( https://old.reddit.com/r/oratory1990/wiki/index/list_of_presets ) then choose that, first.

Apply in RootlessJamesDSP.

Enjoy.

-30-