Wouldn't mind some input on my theatre build sound proofing

Hi,

I should start off saying that I have been reading through the theatre forum on construction and sound proofing for about a year and half now while I have been slowly working on my dedicated theatre. First of all I have to say that I have had many ideas from what many of the members have done along with learning much about design and sound proofing. There are individuals on here like Ted White and Denis Erskine (along with many others) who have greatly educated me on sound proofing by their many posts and I greatly appreciate their knowledge. Especially since I originally thought sound proofing was just a matter of throwing some insulation up in the rafters, I can tell you that has certainly changed. So I am now getting to the point to where construction is moving along and I would like to make sure that I am doing everything correct. I'll explain what I am doing, what I have done and what my objectives are.

My main objective is to keep the sound from going up through the ceiling, as the bedrooms are just above it.

My plans so far is to use 5/8" DD GG along with sound clips and insulation for the ceiling. I have pot lights which will be installed but they are in boxes that I built from the 5/8" DD and GG to keep in the sound and they will be sitting on top of the ceiling. I will also be using the recessed technique in the ceiling to install that sound clips as I have an older house and only have a 7 1/2 foot ceiling. As for the walls I was thinking of just putting in one sheet of 5/8" dry wall along with resilient channel. I am aware of the chance of shorting out the resilient channel so I will be the only one installing the dry wall. I don't trust any one to understand why it is so important to not short it out plus I am doing most of the work myself. All the electrical outlets will have putty around them to keep the sound in. The walls that are along the foundation of the house are 1.5 inches from the wall but have a 1 inch thick piece of styrofoam insulation between the wall and stud. This is because my basement can get very cold and I have also removed the HVAC from the room. The walls are 16" on centre with R14 Roxul insulation in between them. I will also be putting in double French doors (I know they are not great for sound proofing) but they will not sit right below the bedrooms more in the area of the hallway that is upstairs.

Like I said my main goal is to keep sound from going straight up through to the bedroom. I figure with the DD GG and sound clips that the ceiling will no be the weak point. My main concern is about flanking noise. I read that keeping the walls an inch or more from the foundation walls will mechanically separate the two and make it harder for sound to travel but I also wonder about the foam that I put behind it and where they are nailed into the top will cause flanking. I am also wondering if the use of resilient channel is needed to stop any flanking. I am not so worried about sound getting out of the room in to the basement as I am more concerned about it flanking and getting into the bedrooms above. That is why I am planning to use resilient channel and only a sheet of dry wall.

I should also mention that I have a tele-post that I would like to remove. Don't worry I won't just casually remove it, I will bring in a structural engineer and have the engineer figure out a way to compensate for the removal. I will also pull a permit from the city to have it done and inspected. But then again I might not have it removed as it is still up in the air.

I also have a 5x3 foot window in the basement which might need some consideration.

I will post pictures of what I am doing and have some more questions and would greatly appreciate any input.

Thanks
Aaron.

Thanks for the response. I am currently taking a break from reading about your theatre build as it is a long post but a good one. Your info on the removal of the telepost is very useful to me as I am also in Calgary. I am curious who you used for a structural engineer company and how much they charged? I have a quote of $800 for the engineer plus of course construction costs. How much did your steel plates and supports cost? The span between the walls is about 12 1/2 feet.

As for the mass and dampening of my walls I was wondering if it is necessary due to the fact I am not worried about sound leaking in to the next room, rather I am worried about it flanking in to the rooms above. I know this last part can be a little tricky.

Thanks for the info. I'll give Grant engineering a call and see what they say. As for the Wood beam method is there a reason why you didn't go for it, did you ever get an estimate on doing it this way? The metal beams sounds a little pricey. My measurement were a little off the room is 14 1/2 feet wide.

I didn't even know that 2x16's exist. I have a problem of already having a ceiling that is 7'6" so I don't think I would want to have anything that big down there. I gather from the tittle of your thread that you are in Aspen Woods which means you probably have new 2 story house but mine is a bungalow. I wonder how that would factor into construction of a new support. I guess I'll have to ask the engineering company.

I don't suppose they offered you an alternative such as to add 3 2x12's or 4 2x10's?

Thanks for the general rule of thumb, this gives me something to think about and if it is worth doing. It will also give me something to discuss with the engineer, which I called today and they closed for the holidays. I will have to wait for another week to reach someone.

I just decided to do this and started working on this last night. This is extra work that I didn't want to do but I would hate to only have a mediocre room because of just a little extra work. I'll tell ya', the amount of work I originally thought that I had to do of just stuffing in some insulation between the joists has exponentially changed. But since I want it done right I am sure I will be happy in the end when I can watch a hockey game with friends and be cheering loud without waking up my wife.

Help and advice from gurus like yourself is greatly appreciated.

Dennis, thanks for your input as a matter of fact I would be happy with any input on my build from someone of your knowledge.

I have decided to go back to doing DD and GG on the walls and buying more whisper clips instead of using resilient channel. I just keep thinking I only have once chance to do this right unless I feel like ripping down my work and redoing it, and I really have no interest in doing that.

As you probably know Green Glue is cheaper in the USA so I order mine from the US and have it shipped to a warehouse just across the border in Montana. I go down to the Taber area on occasion where I then drive to the border to pick up items. But I haven't ordered all the Green Glue I need, as I have decided to expand the project. So I might be interested in your pail, let me know how much you want for it.