I want to know the answer to the following question:
When was the business booming for do it yourself sound fanatics?
All the background I'm provided with is that "The complete technical disclosure of the Columbia LP by Peter C. Goldmark, Rene' Snepvangers and William S. Bachman in 1949 made it possible for a great variety of record companies to get into the business of making long playing records.". Is that enough to answer the question?