It turns out that HomePod equalizer settings work automatically, and there are no manual options. So sayeth Eddy Cue at the Pollstar Live conference (via AppleInsider).
Update: As it turns out, there’s a simple workaround that I feel silly for not thinking of.
HomePod Equalizer Settings
Just like how the HomePod automatically tunes audio according to room dynamics, it uses analytics to set EQ levels for each individual song. Patrick Ryan, cofounder of Eventellect, took to Twitter to share the news.
This might disappoint audiophiles who like to fine tune their music, but then again these types of users most likely already have an audio system. It doesn’t come as a surprise though, as Apple wants the HomePod to have that magical “just work” capability like its other products.