Thanks to Bill Porter
How did Bill cross paths with Elvis?
After the '68 Comeback Special, Elvis recorded some songs at the beginning of 1969 to get into the charts again and cemented his comeback. There was a mixing problem on one of the songs, Suspicious Minds, around the unusual fade out. Elvis' record producer Felton Jarvis asked sound engineer Bill Porter to help. Bill helped and left.
A few months later Elvis returned to live performances in Vegas. Afterwards he called Porter and asked him to help fix the sound in the main showroom as he could not hear himself and a new Vegas run was scheduled for the beginning of the next year.
When Elvis started rehearsals in January 1970 Porter attended and fixed the sound by replacing the stage monitors (that the hotel's engineers could not get working) with his own sound equipment and laying the column speakers on their sides on the lip of the stage, propping them up to aim at Elvis, who was very happy with the result.
For the first time EVER Elvis could hear himself on stage.
Elvis insisted that Porter mixed the sound of these January 1970 shows (even though the sound engineer had no previous experience recording live sound). Bill quickly learned about acoustic feedback during the first song but backstage after the show film stars and musical artists kept complimenting Elvis that Porter's sound was "just like the album."
From then on Bill Porter mixed all Elvis' live concerts.