Videos don't do well on Hacker News, but I encourage people to at least watch the first couple minutes of this one. The oscilloscope visual overlay is interesting and the editing is really good.

Also, given the topic (audio equalizers) there's no way it could have been a blog post.

A pleasant, if muted, layman's 10 minute journey to explain sound, eq, and speaker response. It gets juiciest on room eq correction/compensation, approaching the 9 minute mark.