glass door how much isolation they do?

Hi John and every body, in many of john sayers design i see the use of glass patio doors as double foktion , sight and door between cr and studio. I wonder how many DB's do these doors reduce (my studio window do 52db so is the very expensive studio door...) and where can i buy them (a linkto a web-site will be nice or can you give rough costs) thanks guy

Guy - we've just put in some doors into a studio locally. They are aluminium doors in two types. They have either 10mm or 8mm glass. One is a slider and it's rated at 32db with 10mm glass. The other is opening doors that are also rated at 32db with 10mm glass. We wanted the wide opening doors as they lead into the drum booth and we wanted to be able to wheel the piano in there if we needed an iso room for the piano. The other day they installed the doors and the owner setup a 600watt bass amp in the drum room and sealed the doors. (we have guitar line links between rooms so he could stand in the main studio and play the amp in the drum room. He wound the bass amp up and closed the doors. He said he could just hear the bass amp faintly, he was very impressed. Here's the cross-section and mounting system of both sets of doors. I hope this helps. cheers john

thanks a lot john, can you give me a link to where you can buy these doors? or is it that just normal patio door sold in any building shop? make any sense to build them custom-made with 42db glass. all in all, do you think this design is cheaper than going with 2x52db small window + 2x 52db doors? cheers guy