Might be little long for the Harper's letter's column, but who knows, maybe they're run it. Good luck.
(I would have mentioned Hydrogenaudio.org too, the grandaddy of online 'objectivist' audio, and going further back, to the print era, the mainstream magazines Stereo Review, Audio, and the niche but memorable Audio Critic and Sensible Sound, but that's me)
This forum reminds me a lot of “The Sensible Sound” magazine from back in the day, my guide in the pre-internet days. Every piece of audio gear purchased in the 80’s was from discovery in their pages. I had every single issue ever issued, and had them until a couple years ago. Pieces of gear that immediately come to mind:
Energy Reference 22 speakers (still have 2 pairs to this day, both in use)
Superphon Revelation Preamp and power amp (had until a couple years ago)
3D Acoustics 3D610B 3 piece speaker (given to a relative who used them until a few years ago)
Systemdek Turntable (long gone..)
Hafler DH500 amp and preamp
Had a couple other amps that forgot—a Belles maybe?
This was the only forum post that I found mentioning the magazine, so had to reply. Probably not known because half the forum members were not born yet when it was published…feeling really old now…