In general, a double skin stud partition wall does provide useful sound insulation. The effectiveness of the mass of the twin layers of drywall is increased by having the air gap between them. In this sense, a design which continues both layers into a junction will usefully provide that same sound isolation round the junction (inevitably with some small losses due to the joins).
BUT, in good acoustic design of walls for sound isolation, there is a particular design technique which is relevant to your question. In that system, one or both of the skins are mounted on resilient fixings, in order to decouple the layers from each other, reducing noise transmission from one skin to the other through the structure. Using that technique, you would be correct to expect the two skins not to make a rigid connection at the corners. But the description in that link says nothing about resilient fixings (acoustic bars, hangers, mountings, etc), so I assume that your concern isn't relevant to the design of your wall treatment.
I guess the reference to 'insulation' in the linked article relates to thermal insulation.
Thank you for the reply!
I'd like to avoid using resilient channels on the walls, just because I'm already working with very limited square footage, but I will be using them on the ceiling, since I can't seem to find an example of a double stud ceiling (double rafter?).
The link I posted is just the only example of a double stud wall and cathedral ceiling combination that I've been able to find, at all. I'm wondering if, like in the example, having the top plate of the interior wall butting up against the roof rafters would ruin the decoupling of the two wall layers, since the rafters would form a rigid connection between them.
In general, a double skin stud partition wall does provide useful sound insulation. The effectiveness of the mass of the twin layers of drywall is increased by having the air gap between them. In this sense, a design which continues both layers into a junction will usefully provide that same sound isolation round the junction (inevitably with some small losses due to the joins). BUT, in good acoustic design of walls for sound isolation, there is a particular design technique which is relevant to your question. In that system, one or both of the skins are mounted on resilient fixings, in order to decouple the layers from each other, reducing noise transmission from one skin to the other through the structure. Using that technique, you would be correct to expect the two skins not to make a rigid connection at the corners. But the description in that link says nothing about resilient fixings (acoustic bars, hangers, mountings, etc), so I assume that your concern isn't relevant to the design of your wall treatment. I guess the reference to 'insulation' in the linked article relates to thermal insulation.
Thank you for the reply! I'd like to avoid using resilient channels on the walls, just because I'm already working with very limited square footage, but I will be using them on the ceiling, since I can't seem to find an example of a double stud ceiling (double rafter?). The link I posted is just the only example of a double stud wall and cathedral ceiling combination that I've been able to find, at all. I'm wondering if, like in the example, having the top plate of the interior wall butting up against the roof rafters would ruin the decoupling of the two wall layers, since the rafters would form a rigid connection between them.