Cabine and SAS

Hi there, I just bought for a really good price a cabine (three walls in fact) that I want to use to do a SAS to avoid the sound to come outside via the door. Here is the link on what I bought http://www.fr.ricardo.ch/acheter/musiqu ... 609524160/ (scroll down to see the pictures, the plan is on the last pic) I will have to cut it from 2m41 to 2m18 but my main concern is about how to fixe it on the ground and ceiling so that it makes no links transmissions. I figure out I have to place some kind of elastic or rubber downside and upside to avoid sound transmission. Any idea welcome ! To be clear 100% theses three walls will go in the corner of my studio where the entry door is and will provide both SAS (stopping the sound) and maybe a cabine for recording voices. I receive it next week !!!! For the price I paid (around 200 euros) it is a good trade!!!