bigshot
Headphoneus Supremus
In the 70's HK provided to its dealers an excellent LP of the impact of fr on reproduction. Heck, it was evident on the Bose 901s, and even more so one some other more critical loudspeakers.
In the 70s, my brother had a fantastically expensive McIntosh system with custom speakers and a nice Thorens turntable. He had a test record with separate bands of tones covering the full spectrum of human hearing. After a dozen playings the super high frequencies started turning into a mush of distortion. The delicacy of the modulations in the grooves required to reproduce those super high frequencies didn't hold up to the mechanical means of playing the record. Most LPs had rolloffs at the top to prevent premature record wear. Wanna bet that test record you remember was dealing with frequencies well below 14kHz?