Use of egg crates was never about soundproofing.

That was used to create the reflective/absorptive boundaries needed for acoustics with hot mic in small space. And it worked well for that purpose in many a small radio station or recording booth setup.

But acoustic ISOLATION was and is an entirely different physical aspect to conquer.

Today we can get panels that do both tasks, although the isolation task can still be quite formidable at times.


--Mac