To truly block audio, you might want to different the surfaces. Any sort of continual content functions as an acoustic bridge that easily moves vibrations from a single space to the following. Acoustic underlayment units differ in the straight plywood solution because the methods elevate the flooring on sleeper boards. https://trentonwhvwt.canariblogs.com/helping-the-others-realize-the-advantages-of-acoustic-floor-underlay-53581873