Not threadiverse but here are some audio communities outside of corpo social media (stolen from Aftermath):

• Audio Science Review is notorious and fairly new in the grand scheme of things, a forum that deserves its own post. They pride themselves on doing objective, scientific analysis of speakers, amplifiers and home audio equipment generally.
• Super Audio Best Friends is another audio forum that apparently has had beef with ASR’s methodology.
• Audiogon is also a well-known, good and reliable audio forum.
• If you want a forum that is just people talking about old speakers specifically, Audiokarma is the destination. Speakers have generally gotten better and more efficient over time, but old speakers have their defenders, and this forum has some fairly interesting and unique information that does not exist elsewhere. It has a sister site called Videokarma that I had no idea existed before writing this blog.
• For everything involving headphones, Head-fi’s forums are probably the best and the ones I root for the most with audiophile stuff. It’s where I found my favorite closed-back headphones. They have their own convention, Can Jam. I probably respect this forum the most.