The best equalizer apps for Android - Android Authority
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
Schiit Loki: This equalizer that lets you tweak your music - CNET
Headphone EQ with REW + EARS
Amazon.com: RadioShack Stereo Amplified Listener with 3-Band Equalizer - Compact, Portable - Fits All Headphones with 1/8" Plug : Electronics