I'v ripped out the carpet, drop ceiling
Excellent! Good start.
and bottom half of the drywall due to wainscotting being glued.
Good! so you only need to remove the other half now, to get down to the situation you need: bare studs all around.
Also, that plastic sheeting is a red flag: that's probably meant to be a vapor barrier, but it can't stay where it is: since you'll be putting up new drywall on your new inner leaf, you cannot leave the vapor barrier in the middle of the wall: water vapor inside the wall will condense on it, creating a mold problem, and a damp problem. The vapor barrier has to go directly up against the wall surface that is warmest in winter.
They didn't insulate the walls so I will have to do that while the walls are open.
Right! Definitely! Use the correct type and density of insulation, not just "any old stuff". The wall is an acoustically resonant cavity: tune it wisely, and intelligently...
There are support poles down the center of the basement. My plan was to have them between two walls
You seem to be confusing issues here, and wasting space...
To properly isolate a studio, this is how you do it:
MSM-two-leaf-WallChunk-conventional--NOT-inside-out--one-room--S06.png
Take a close look: You build one wall around the area where the studio will be, to enclose it completely, creating an "outer-leaf shell". That framing has drywall on just ONE side of the studs: the other side remains open, but is filled with insulation. That "outer leaf" must be sealed air.tight. Then you build the actual studio inside that space, as a completely separate, self-supporting room, with four walls and a ceiling. That inner-leaf wall is also a stud frame with drywall on only ONE side of it, and insulation in the cavity.
You can build that inner-leaf room either "conventionally" as shown above, with the drywall on the room side of the studs, or you can build it "inside out", like this:
MSM-two-leaf-WallChunk-NOT-conventional--inside-out--one-room--S06.png
Take a close look at that: you can see the drywall is in there, but on the OTHER side of the framing: the drywall faces the cavity, not the room. This has the advantage of being able to use all of the stud bays around the entire room as part of your acoustic treatment. That's a huge advantage. In the thread I linked you to yesterday, "the corner control Room", that's how I did it. The walls are all "inside out", with the studs facing the room, and all of that "free" space is then used as part of the treatment, in various ways. This is the best possible way to "build in the treatment", as you wanted to do.
But you have a problem: you already built some framing, and it is no use for either the outer leaf OR the inner leaf! It can't be the inner leaf because it is mechanically connected to the outer-leaf walls, and the ceiling. And if it is the outer-leaf then it is wasting space, and the final inner-leaf room is going to be too small.
If that's the outer leaf for your room, then it could have been in line with the support pillars, making them part of the wall itself. That's fine for the outer leaf, because the pillars ARE the outer leaf! So there's no problem including them as the outer-leaf wall. That wall would then be the dividing wall to the play room. IT would be about a foot over from where it is now, giving you more space to build your inner-leaf room: Your inner-leaf room could the be wider.
So there's your dilemma: You framed up something that isn't much use! It can't be the inner-leaf, and it can't be the outer leaf...
OK, you did mentioned that you don't need much isolation (I'll get back to that point below...), but you didn't say how much isolation you need, in decibels, so I can only speculate form here on. Once you come up with that number (it is THE key number to your design...), then we can be more specific. But assuming that you only need moderate isolation, it MIGHT be possible to not build a separate frame for the inner-leaf, and instead create the inner-leaf with a decoupling system that is attached to the outer-leaf stud frame. There's two options for that: one is to use something called "resilient channel" ("RC") which looks like hat channel but is very, very different. The other is to use ordinary hat channel, but mounted on isolation clips, such as RSIC or Genie, or some others. Both of those options will work, but the "isolation clips+hat channel" option is better. You could even do that on your current stud frame, but then you would lose the window, because there's no way of dealing with that: you would have to seal up the wind, and just put drywall completely across it.
So, if you want to keep the window, then RC or clips+channel are not options. You can only do that with two frames. You simply mount a second window in the inner-leaf, exactly opposite the existing window, and you can do that with either conventional framing or inside-out framing.
So that's your situation at present: Unfortunately, you didn't see Greg's signature before you arrived on the forum! And now you have a problem: the framing you already put up is the problem.
I planned on insulating all walls and ceiling with Safe n Sound to help dampen the sound.
When you say "dampen the sound", are you talking about isolation, or treatment? Those are two entirely different and unconnected things. If you are talking about isolation, then yes, you do need to fill the cavity in between your inner-leaf and outer-leaf with the right insulation: That's part of the isolation system! You MUST have that. The wall is a resonant system, and the insulation is necessary to dampen the various types of resonance going in WITHIN the cavity, since they all rob you of isolation. So yes, for isolation, you do need to fill the wall with insulation. But that has nothing at all to do with the acoustic treatment, which goes inside the room, not inside the walls. If your walls are "inside-out", then you can put that treatment in between the stud bays and cover it in any of several ways (take a look at the corner control room thread, to see what I did there), and there are various ways of tuning that treatment to deal with specific issues in the room, and tame it properly. And if your walls are NOT inside out (built conventionally), then you do the treatment by hanging panels of the right type at the right locations on the walls and ceiling. But treatment has noting at all to do with isolation.
There is also a window which will be the front of the room that i don't want to lose.
You can keep it, no problem, as long as you do a proper 2-leaf system. You can't keep it if you use clips or RC, because there's no framing on the inner-leaf with that system, and thus no place to mount the second window. You need framing there to put the window in. It MIGHT be possible to do a second frame on only that side of the room, with RC or clips on the other sides, but that's not so easy to pull off, as you'd need sway braces and seismic snubbers to support that wall without coupling it to the outer leaf walls or ceiling.
I felt like my only option for my door was to center it on the back wall. Because of the beam running down the center I couldn't put it on the side.
That's the best place for it!
You should never put doors in the corners of a studio, because "corners" is prime real-estate for bass trapping, and speaker soffits. Corners have a major acoustic advantage, the best place to put treatment, and should not be wasted on mundane things like doors or windows. Having the door in the middle of the wall is the best place.
As for isolation, I don't need total isolation.
So there is nothing in New Jersey that could trash your recording and mixing sessions? No thunder, rain, hail, or wind? No aircraft or helicopters flying over? No sirens from ambulances / police / fire engines? No trains? No cars arriving / leaving / driving past? No dogs barking outside? No lawnmowers? And nothing in the house either, such as water running in pipes, fans, pumps and other motors, people walking on floors, doors closing, people talking, vacuum cleaners, washing machine, radio, TV, furnace.... There's hundreds of possible sounds that could destroy a good recording, if they get into the mics in your control room, or mess your concentration while playing instruments, or mixing... Are you CERTAIN that your room will not get any of that?
This is why it is so important to actually define how much isolation you will need, in decibels. That's what determines how you build your studio.
I have an electrician coming to run a sub panel to the basement.
... and from that sub-panel, you can have exactly one electrical feed coming into your studio, through one single conduit. From there, you can distribute the power to where it is need using only surface-mounted electrical distribution. You CANNOT cut holes in your drywall, like you would normally in a house, for your outlets, switches and lights, because cutting a hole in the drywall totally trashes your isolation! Even a very small hole... So warn your electrician that, inside the room, everything is surface-mount. No penetrations.
I have someone coming to give me a quote for a mini split.
That's fine, but that's not HVAC! Mini-splits heat and cool, but they do not ventilate. A mini-split system by itself does not bring in fresh air, and does not expel stale air. For a studio, that's fundamental! I don't see any provision for ventilation in your current situation...
You need to re-think your entire build... start by stopping!
Stop building, and get down to planning properly and designing properly. Then, when the design is complete, you can take down the framing you did, and re-do it properly, where it needs to be, and carry on from there.
- Stuart -