There's also a decent written article here: https://www.vintageguitar.com/16339/heil-talk-box/ — after seeing the front page "Wall of Sound" article, I remembered hearing the story behind the Talk Box. I remember Bob Heil (who made the Talk Box a piece of touring gear instead of a studio oddity) was also around in that era and was one of the audio engineers who helped make concert sound more clear and listenable (rather than just throwing more speakers at it).
There's also a decent written article here: https://www.vintageguitar.com/16339/heil-talk-box/ — after seeing the front page "Wall of Sound" article, I remembered hearing the story behind the Talk Box. I remember Bob Heil (who made the Talk Box a piece of touring gear instead of a studio oddity) was also around in that era and was one of the audio engineers who helped make concert sound more clear and listenable (rather than just throwing more speakers at it).