Sound insulation is crucial in studio design as it determines what is possible and impossible within a studio. Sound generated inside the studio must stay inside, while sound from outside must remain outside. Insulation is a science in itself. Simply placing rubber, tennis balls, or foam under a floor is pointless. Structures must be calculated based on masses, mass-spring systems, material properties, and the amplitude and spectral composition of the sound to be insulated. Since sound insulation can be costly, it is essential to calculate which method suffices to achieve the optimal price/quality ratio. Bert Stoltenborg from IPSIS Acoustics has written several articles on this subject for various publications, including Homerecording Magazine, Bandcoach Magazine, Behind the Corner Magazine, Homerecording.be, and Studiotips.com. The article in Homerecording Magazine can be found on the Bax website (NL). A technical article on the basics of sound insulation can be found here (NL).