Hi,
I have read the statement below from Phillip Newell, which tells you how to get 20 dB of isolation:-

“With 40dB of low frequency isolation, we would only need an internal floated structure with 20dB of isolation in order to achieve 60dB of total isolation. This may be achieved by internal floated walls of 10cm thickness, such as of sand- filled, concrete blocks, spring isolated from the floor, with a 5cm mineral-wool lined airs pace between.”

If i wanted double the isolaion (40dB), would i be able to acheieve this by doubleing the floated wall to 20cm and doubling the air space to 10cm, or does it not work like this. I know it does not work like this for fixed walls as a doubling of size for a concrete wall adds 6dB of extra isolation.

Cheers

Brad