Who would have ever thought that Sun Records in Memphis, Tennessee, would be the subject of an article in Popular Mechanics magazine? This article explains the decaying reverberation echo heard on most Sun records made in the 1950s. Sam Phillips transferred the flat recorded sound to a separate tape recorder to add on the electronically created echo, described many times as a “slapback echo”. Most other recording studios of the era would create a resonance-based echo by feeding the flat studio recording through an actual echo chamber. Duane Eddy recorded at a studio in Arizona that had a metal water tank obtained cheap at a scrap yard for an echo chamber. The audio engineer ran cables to the inside of the tank with a speaker and a microphone to capture the sound of the metallic resonance to add to the recordings. The Chess studio in Chicago had a long piece of sewer drain pipe suspended horizontally from a steel beam in their building, with a speaker and microphone on each end. The Norman Petty studio in New Mexico had the attic of their building with the walls lined with ceramic tiles, installed professionally by Buddy Holly’s father and his three sons. In the middle of the attic was and odd-shaped blob made out of a ceramic type material specially designed by a university audio acoustics professor for the purpose of deflecting sound. Again speakers a microphone were placed inside. In every case the flat sound of a band and singer recorded in their small studio rooms would be fed through a speaker inside these echo chambers to create more resonance which would then be recorded separately and then added to the original flat recording. Sam Phillips at Sun Records, on the other hand, used an electronically created echo. Echo chamber resonance spreads out and diffuses. Sam Phillips’ echo would repeat rapidly, a staccato, getting quieter with each repetition. The Phillips echo is a pretty unique sound. It is describe in a little bit of detail in this article.
During this era there were also much larger studios, usually older, that were built with the intention of recording large orchestras. These studios often did not need added echo or resonance as the size and designs of the rooms created their own that could be separately mic’d and added to the mix.