Gigalittle Studio Build Thread
Posted: Sun Oct 20, 2013 5:43 am
Hi Everyone.
I have browsing the forum for a few years now but this is my first post, so please be gentle if I forget anything...
I am planning to build a 2 room studio in the basement of my home in central Massachusetts USA. I would like to record full bands (including drums) and also have a place to jam without disturbing the neighbors. The basement is a walk out - the back half is above grade, the front half is poured concrete. The existing above grade walls are 2x6 construction. The joists are 2x10's spaced 16" off center. The height from the concrete floor to the bottom of the joists is 7' 10". I am shooting for a finished ceiling height of about 7' 6". There will be bulkheads for HVAC trunk lines (not shown) where the ceiling height will need to be lower (about 6' 8").
I would like to achieve approximately 60 dB of isolation. My initial measurements of my band playing in the basement are typical for rock music - about 100 dB average, with peaks about 115 dB. The closest neighbors are about 50 feet away. At present when we rehearse in the space "as is" the music is clearly audible (especially the bass guitar) from the property line. We have only had one noise complaint so far which was during the summer (when the neighbors had their windows open) I have discussed it with them and it really is not an issue as long as we stop playing around 9:30pm. My goal would be to achieve enough isolation that just a subtle "thump thump" is audible from the property line - allowing us to play later into the evening. The local noise ordinance states that to be in compliance the noise must not exceed the ambient noise level by more than 10 dB at the property line. Unfortunately our neighborhood can be very quiet at night so the ambient level is low. I would guess around 40 dB, but my meter will not register below 60 dB.
I would also like to isolate enough that my wife can relax upstairs while we are playing without going too nuts. The house is two stories. The bedrooms are on the 2nd floor and are already pretty well isolated from the basement. You can hear a bit of bleed through the duct work when we play, but that is about it. The living area directly above is another matter. Again my goal would be to isolate to a subtle "thump" of bass through the floor so watching TV, for example, would be possible.
My plan is to build independently framed double stud 2x4 walls for 2 rooms in the basement: a control room and live room. I will not be doing any angled walls so that the basement would be convertible to other uses like a home theater or a rec room if we ever need to sell the house. My budget for this project is about $20,000 The ceilings will suspended from isolation clips and hat channel. I have already consulted with a structural engineer and have completed sistering of joists that needed to be reinforced to support the additional load of the 4 layers of 5/8" drywall.
I am getting ready to beef up the existing subfloor with 2 layers of 5/8" drywall between the joists, and will also beefing up the exterior walls on the above grade sections between the studs.
My main concern at this stage is what to do about the existing ductwork which is servicing the living room, kitchen and dining room on the ground floor. There is a fair amount of it: 2 large trunk lines for main send and cold air return, which hang below the joists, and several branching ducts which connect to registers on the ground floor. In all this ductwork covers about 25% of the total ceiling area. This ductwork is not part of the studio design. (For studio HVAC I will be running separate ducts later)
The problem as I see it is that all this ductwork is likely going to be the weakest link in my isolation. I am trying to figure out the best way to deal with it.
My first idea was to "box it in" like this:
The compromise here is that this would be creating a 3 leaf situation in these areas but the ducts would at least be completely sealed off from the studio (behind 4 layers of drywall). The decoupled air gap would be limited to 1 5/8" between the inner leaf and the "boxed in" duct but there would be an additional 9 inch air gap between the middle leaf and the subfloor. The rest of the ceiling would have an air gap of about 10 5/8" where there are no ducts interfering due to the additional 1 1/4" blocking on the joists to align the isolation clips. I am wondering if the inconsistent air gap would "average out" for isolation performance or would the smallest air gap govern?
I have also seen some builds where it was done more like this:
The compromise here is that the outer leaf has inconsistent mass since there is no way to beef up the subfloor above the duct, but the decoupled air gap is a consistent 9 3/8" throughout. I am also concerned that the ducts would only be behind 2 layers of drywall and there are direct openings through the subfloor where the registers penetrate into the rooms above, so the outer leaf actually is not completely sealed.
So which is a better compromise: an inconsistent air gap and some 3 leaf situations, or, an inconsistent outer leaf with a consistent air gap?
If I go with solution 1 which my "gut" tells me is better, would I be just wasting the money for the extra drywall?
Thanks in advance!
I have browsing the forum for a few years now but this is my first post, so please be gentle if I forget anything...
I am planning to build a 2 room studio in the basement of my home in central Massachusetts USA. I would like to record full bands (including drums) and also have a place to jam without disturbing the neighbors. The basement is a walk out - the back half is above grade, the front half is poured concrete. The existing above grade walls are 2x6 construction. The joists are 2x10's spaced 16" off center. The height from the concrete floor to the bottom of the joists is 7' 10". I am shooting for a finished ceiling height of about 7' 6". There will be bulkheads for HVAC trunk lines (not shown) where the ceiling height will need to be lower (about 6' 8").
I would like to achieve approximately 60 dB of isolation. My initial measurements of my band playing in the basement are typical for rock music - about 100 dB average, with peaks about 115 dB. The closest neighbors are about 50 feet away. At present when we rehearse in the space "as is" the music is clearly audible (especially the bass guitar) from the property line. We have only had one noise complaint so far which was during the summer (when the neighbors had their windows open) I have discussed it with them and it really is not an issue as long as we stop playing around 9:30pm. My goal would be to achieve enough isolation that just a subtle "thump thump" is audible from the property line - allowing us to play later into the evening. The local noise ordinance states that to be in compliance the noise must not exceed the ambient noise level by more than 10 dB at the property line. Unfortunately our neighborhood can be very quiet at night so the ambient level is low. I would guess around 40 dB, but my meter will not register below 60 dB.
I would also like to isolate enough that my wife can relax upstairs while we are playing without going too nuts. The house is two stories. The bedrooms are on the 2nd floor and are already pretty well isolated from the basement. You can hear a bit of bleed through the duct work when we play, but that is about it. The living area directly above is another matter. Again my goal would be to isolate to a subtle "thump" of bass through the floor so watching TV, for example, would be possible.
My plan is to build independently framed double stud 2x4 walls for 2 rooms in the basement: a control room and live room. I will not be doing any angled walls so that the basement would be convertible to other uses like a home theater or a rec room if we ever need to sell the house. My budget for this project is about $20,000 The ceilings will suspended from isolation clips and hat channel. I have already consulted with a structural engineer and have completed sistering of joists that needed to be reinforced to support the additional load of the 4 layers of 5/8" drywall.
I am getting ready to beef up the existing subfloor with 2 layers of 5/8" drywall between the joists, and will also beefing up the exterior walls on the above grade sections between the studs.
My main concern at this stage is what to do about the existing ductwork which is servicing the living room, kitchen and dining room on the ground floor. There is a fair amount of it: 2 large trunk lines for main send and cold air return, which hang below the joists, and several branching ducts which connect to registers on the ground floor. In all this ductwork covers about 25% of the total ceiling area. This ductwork is not part of the studio design. (For studio HVAC I will be running separate ducts later)
The problem as I see it is that all this ductwork is likely going to be the weakest link in my isolation. I am trying to figure out the best way to deal with it.
My first idea was to "box it in" like this:
The compromise here is that this would be creating a 3 leaf situation in these areas but the ducts would at least be completely sealed off from the studio (behind 4 layers of drywall). The decoupled air gap would be limited to 1 5/8" between the inner leaf and the "boxed in" duct but there would be an additional 9 inch air gap between the middle leaf and the subfloor. The rest of the ceiling would have an air gap of about 10 5/8" where there are no ducts interfering due to the additional 1 1/4" blocking on the joists to align the isolation clips. I am wondering if the inconsistent air gap would "average out" for isolation performance or would the smallest air gap govern?
I have also seen some builds where it was done more like this:
The compromise here is that the outer leaf has inconsistent mass since there is no way to beef up the subfloor above the duct, but the decoupled air gap is a consistent 9 3/8" throughout. I am also concerned that the ducts would only be behind 2 layers of drywall and there are direct openings through the subfloor where the registers penetrate into the rooms above, so the outer leaf actually is not completely sealed.
So which is a better compromise: an inconsistent air gap and some 3 leaf situations, or, an inconsistent outer leaf with a consistent air gap?
If I go with solution 1 which my "gut" tells me is better, would I be just wasting the money for the extra drywall?
Thanks in advance!