Schiit Loki: This equalizer that lets you tweak your music - CNET
How to EQ your Bluetooth headphones - SoundGuys
Simulate and Create Your Own EQ Settings for Headphones and IEMs
Amazon.com: Serafim A1 Gaming Headset with Exclusive Equalizer Detachable Mic Bass Boost 3D Surround Sound for PC Xbox One Series X|S PS5 PS4 Nintendo Switch Mac iPhone Mobile 3.5mm Jack - Wired