Double wall without double ceiling?

Hi, I've got a walkout basement I'm trying to make into studio space. I need to add a 2 leaf system to the walkout (framed) wall to keep out airplane noise. I record acoustic instruments only, so drums should not be an issue for isolation. I'm wondering if I can get away with just the double wall without the isolated ceiling as in room within a room construction. I don't need the isolation from the upper floor as I won't be recording when anyone is in the house upstairs. I also don't want to sheetrock my ceiling and cover up wiring and plumbing that may need to be accessed in the future. This then brings up the issue of how to attach the upper plate of the second wall to the existing structure without creating flanking paths that will negate anything I try to add in terms of soundproofing mass. I had thoughts of boxing in the floor joist span a few feet into the room with layers of sheetrock cut to fit the span like a header and then sealing airtight with caulk to create a soffit type of ceiling just around the perimeter of the outer wall. Am I just wasting my time with this approach? Thanks Scott

I'm not sure I understand what you're trying to accomplish (other that isolating airplane noise). I can't see the picture in my mind of the space you're trying to work with. Any chance you can snap a couple of pictures or whip out a quick drawing? len

Thanks, I'll see if I can get some photos or a drawing posted to make it clearer. I was afraid my description was a bit vague. I'll attempt a better description of my situation in the meantime. I have a walkout basement, meaning three of the outer walls are cinderblock below grade. The fourth wall is the walkout side. It consists of 2x6 frame construction with fiberboard/tyvek/ and vinyl siding. I've been in this house for only 6 months. My previous house was a traditional below grade basement with cinderblock walls on all sides. That house had sufficient isolation from outside noise (airplanes) without any additional soundproofing measures added. I'm hoping I can achieve similar isolation to the cinderblock walls by adding a second isolated framed wall as in the 2 leaf system, double layer sheetrock/insulated frame cavity/airspace/second framed wall/double sheetrock. I will then have a sliding glass door and windows to deal with. I plan to make removeable acoustic plugs to hang and seal when I need to record. The next challenge will be how to attach the top of this second wall to the existing structure without doing the room within a room construction where the ceiling rests on the isolated wall frames. I would like to avoid a second ceiling layer of sheetrock to use the existing floor spans for absorption, and to avoid covering up plumbing and wiring that may need to be accessed in the future. I know a picture is worth a 1000 words, I'll try to get something up to better describe my situation. Thanks Scott