New ideas for noise control at home by Al Lees: Well known Science, September 1970. A further old post, but in addition a fantastic information to sound transmission class and how to improve soundproofing with various differing kinds of wall construction. On ocassion we may make other geometrical designs but https://acoustic-performance70817.thenerdsblog.com/37636974/indicators-on-thermal-performance-you-should-know