how soundproof are sliding glass doors

I am building on a new control room to my studio, and I've realized that I can't build any sort of buffer room between the tracking room, and the new control room. The existing wall that I am connecting the new room into is a triple exterior wall, and quite soundproof. So I have the choice of putting in a small window with a double solidcore door to the right, or using 2 exterior sliding glass doors in the middle of the wall, as the window, and the door. I am assuming that the double solid core door will give me more isolation, but I wonder how the glass door idea would do. thanks

correctly designed and built, the solid core doors are likely to give you better isolation than the sliders. depending on how your rooms are laid out, the sliders might be useful for visibility or might cause unwanted reflections. how much isolation do your walls currently provide? if its 50db or less, then a pair of heavily constructed double-glazed exterior grade sliders may be acceptable. what do you mean by triple wall?

I don't know exactly how much isolation I have in db, but on the other side of the wall, where the new room will be, If I have a full band playing in the room, I can't hear any sound when I am about 25 feet from the wall. If I am right up close to the wall, I hear some of the kick, and snare, and a bit of bass. currently the other side of the wall is outside. So when the new room is built, I am still going to hear a bit of kick and snare in the control room, even without a window and doors. But I want to try to eliminate any more leakage that may occur with a window and/or door. What I meant by a triple wall, is: the existing wall of the garage, finished in 1/2 sheetrock. then a 2 inch airgap with a 2 by 6 staggered stud wall with on layer of sheet rock on the outside, and 2 layers of 5/8s sheetrock on the inside. Its insulated with standard insolation rockwool. So I guess its just a double wall. Is there anywhere I can find out just what kind of isolation I can get with 2 exteroir glass doors? thanks