My best friend and I were just discussing this. When we were about 16 we would take the speakers off the Sears "portable" stereo (turntable folded up into the box)... about $49 in 1967 and put them on the floor and put our head in between the speakers. The bass was great at 2"
So, there are stories a few years earlier of me listening with my ear to the speaker late at night to the tube counsel in my bedroom at whisper volume so my parents would not hear. But, I'll put my stake at 16.

