New construction detached studio/rehearsal build

[ErockLeach]

Hello all,

I’m designing a detached band room/studio from ground up on my property and ready to move forward so I decided to start a post with hopes to get some help and feedback.

It will primarily be used as a rehearsal space for a 4-5 piece rock band. Secondary, I plan to add a control room in the future and do some recording, mostly preproduction or demo stuff but with the ability to get quality guitar and vocals tracks. Finally, down the road if I sell the property I want to be able to make it a functional apartment/in-law suite. I have around $25-30k to build it so the budget is lil tight. I want to do what is needed upfront and do it right, and add on down the road (kitchen, control room, improve acoustic treatment, etc). I have construction experience and friends in construction so hoping to pull favors and save cost wherever possible.

I know I need sound reduction, but not sure how much. My sound meter reads approx. 105-110 DB at close range (of the band). I’m 120 feet from the nearest neighbor and I want the sound to be barely noticeable to them from outside when we’re rehearsing/recording. We live near an airport so there’re use to some noise (but also a consideration for inside my room).

Attached is a draft of the layout.

Here’s what I have for design so far:
• 32’ x 22’ exterior dimensions
• Frame 2x4 construction, simply because I have friends that are framers and it is cheaper than block construction.
• Interior walls and ceiling with 2-layers of 5/8” drywall w/green glue in between layers decoupled with resilient channel (not sure which product yet)
• Considering 9-foot high flat ceiling
• Exterior will be stucco, but not sure what to use between stucco and framing yet
• For flooring I’m considering good thick pad with click & lock wood flooring.
• Electrical: 100-amp service coming from main panel at the main house. Panel installed at building with isolated grounds for the equipment. Run A/C and appliances on one of the 120V legs, and all outlets for music equipment on the other 120V leg
• Install Central AC unit with turns in the attic duct work to reduce sound from escaping.
• Still researching exterior windows and installation
• Still researching exterior door and installation. Considering pre-hung solid core door from somewhere like Lowes/Home Depot and building up the door, or install a second pre-hung door on the inside so there’s two doors the sound has to go thru (saw that at another home studio).
• May will leave drywall, kitchen, and bathroom off of the plans. After I close out permits, I’ll come back and add the remaining. If I show plumbing on plans, I know I’ll have to update my entire septic system which is cost prohibitive at this time.

Some questions I’m working on:
1. Main question is should this design reduce noise enough for neighbors?
2. Is the room adequate size for a band to rehearse with room for a few people to hang?
3. Monolithic slab or stem wall? Not sure if one is better for blocking sound
4. Architect can design ceiling/trusses with a pitch or different heights which I thought would be good for reducing reflections, but it will make the resilient channel install more difficult. Is it worth it?
5. Considering a drop ceiling (2’ W x 1’H) around perimeter of ceiling for running AC ducts and lighting so I do not lose soundproofing by putting a bunch of holes in the decoupled drywall. Worth the effort?
6. Other considerations?

Thanks! Hope I included enough info...

Eric

[Soundman2020]

Hi there Eric, and Welcome!

• 32’ x 22’ exterior dimensions

That's a nice sized space. 700 square feet is a decent size for a home studio. However, I have a feeling you might be trying to fit in too much, based on your diagram. You are not yet showing your isolation plan, and that takes up a lot of space. So even though you show 10' dimensions for your control room, the actual interior dimensions after isolation and treatment will be considerably less. The walls could be a foot thick on each side, plus another several inches (or more) for treatment....

I have around $25-30k to build it so the budget is lil tight.

That's just US$ 42 per square foot, for a ground-up build? Yup, "lil light" is correct for sure! You are gong to need substantially more than that. Call a couple of local contractors to find out what the rough going rate is to build a house in your area, per square foot. Add about 20% to that, and you'll have a rough estimate of what it will cost to build a studio. Your budget is far short of what you need. I'd suggest that you need to either increase your budget, or reduce the size of the studio. I would expect something more along the lines of US$ 100 per square foot, for a ground-up build, and even then that's on the tight side. You have excavation, plumbing, and electrical work that needs doing, a slab needs pouring, etc. Those are all costs that a basement or garage conversion does not need to even think about. Then the HVAC system will take a large chunk out of your budget.... I'd suggest a re-think here.

I have construction experience and friends in construction so hoping to pull favors and save cost wherever possible.

Great, but do they also have free access to heavy equipment? Do they have free back-hoes and dump trucks and concrete mixers and concrete pumps and concrete vibrators and concrete finisher / burnishers, and suchlike, which you will need just to get the slab done? Do they have a free crane to raise the roof trusses? Do they have free compressors and nail guns and table saws and suchlike, which you will need for the framing? Do they have free scaffolding and/or ladders? Free drywall lifters? Etc? If not, then there's a lot of tool rental or purchase that you'll need to factor in to your budget. There are so many "hidden" costs in a build like this, that you really need to be careful when figuring your budget. If you have never acted as your own general contractor before, then it might be an idea to hire someone who has, just to coordinate the logistics and come up with realistic estimates. For example, have you considered the cost of insurance for your "crew" during the build? Even though they might be working for free, you are still responsible for their safety...

I know I need sound reduction, but not sure how much. My sound meter reads approx. 105-110 DB at close range (of the band). I’m 120 feet from the nearest neighbor and I want the sound to be barely noticeable to them from outside when we’re rehearsing/recording.

It's a bit more serious than that: not only do want it ti be "barely noticeable", but you also want it to be "fully legal". There are legal limits on how loud you can be. Go to your local municipality and get a copy of the regulations that govern noise in your area. Or check on their website. Whatever number you find there is what you have to aim for. So for example, if the noise ordinance says that the level cannot exceed 35 dB at night, then you need to have 70 dB of isolation between the interior of your studio and the neighbor's property line (105-70=35). That includes both the isolation provided by your studio building, and also the attenuation due to the distance.

We live near an airport so there’re use to some noise (but also a consideration for inside my room).

Yup. You need to measure how loud the aircraft are, as they fly over. You need to make many measurements over several days, to ensure that you cover all wind conditions and all plane sizes. Heavy wide-body jets make a lot more noise, especially in low frequencies, than light business jets or GA aircraft.

• Frame 2x4 construction, simply because I have friends that are framers and it is cheaper than block construction.

How high will the roof be? There's a limit on what you can do with 2x4 framing. If it is too high, or if the roof is unusually heavy, you might need 2x6.

• Interior walls and ceiling with 2-layers of 5/8” drywall w/green glue in between layers decoupled with resilient channel (not sure which product yet)

I think you are misunderstanding how isolation works. Your inner-leaf walls will be fully decoupled from the outer leaf walls, so you won't need any RC. If the drywall is decoupled then it is decoupled. There's no point in decoupling it twice.

Also, your budget does not allow for Green Glue, unfortunately. It's expensive stuff. It would be good if you could do that, but your budget won't let you.

• Considering 9-foot high flat ceiling

For which room? The rehearsal room/tracking room? Or the control room? Or the service rooms?

• Exterior will be stucco, but not sure what to use between stucco and framing yet

I would just do standard stucco. Nothing special, except to make it as thick as you can afford.

• For flooring I’m considering good thick pad with click & lock wood flooring.

Why do you want a "good thick pad"? Don't ever lay laminate flooring on something is not approved by the manufacturer. You don't want it cracking or separating due to the underlay being too thick, or too resilient. Only use the underlay that the manufacturer specifically recommends. Use the thickest one he allows, yes, but nothing thicker.

• Electrical: 100-amp service coming from main panel at the main house. Panel installed at building with isolated grounds for the equipment. Run A/C and appliances on one of the 120V legs, and all outlets for music equipment on the other 120V leg

.... and start grounding. And only surface-mount raceways wtihin the studio itself, with surface mount outlets, lights, switches, etc. You cannot do a typical electrical installation with holes cut in the drywall, as that would trash all of your isolation. You can only allow one small penetration of the drywall, for the main power feed to come in. From there on, it is all surface-mount, within the room.

• Install Central AC unit with turns in the attic duct work to reduce sound from escaping.

Not sure what you mean by "turns in the attic duct work to reduce sound from escaping". Turns in the duct work don't stop sound from escaping. It can reduce transmission along the duct, but does not stop sound from getting in or out. That's what the silencer boxes are for.

• Still researching exterior windows and installation

All windows in the isolated area have to be done with two separate panes of laminated glass: one pane in the outer leaf. one pane in the inner leaf. The surface density of the glass in each case needs to be the same as the surface density of the leaf it is in, or higher. And of course, all of those windows are non-operable. That goes without saying.

Ditto for doors.

Considering pre-hung solid core door from somewhere like Lowes/Home Depot and building up the door, or install a second pre-hung door on the inside so there’s two doors the sound has to go thru (saw that at another home studio).

"Considering"? Actually, you have no choice! All doors have to be done in pairs, back-to-back. One door in each leaf. That also goes without saying. There is no other way of getting high levels of isolation, which you will need.

• May will leave drywall, kitchen, and bathroom off of the plans. After I close out permits, I’ll come back and add the remaining. If I show plumbing on plans, I know I’ll have to update my entire septic system which is cost prohibitive at this time.

Once again, you have no choice. The plumbing has to be in place before you even pour the slab, and I kind of think that the inspector would notice the unapproved plumbing at the time he comes to inspect your slab! You can't lay plumbing under your slab after it is already done. It needs to go in now.

You HAVE to get all your permits in order before you can even start.

You might want to read this: http://www.johnlsayers.com/phpBB2/viewtopic.php?t=4442

1. Main question is should this design reduce noise enough for neighbors?

You didn't provide enough details of the isolation plan to be able to determine that, and you didn't mention how much isolation you need. You'd have to tell us what the target isolation number is (in decibels), and you'd also need to specify the surface density that yo uare planning to use on each of your isolation leaves, as well as the distance between them (MSM air gap), and the amount of insulation you plan to use in there. Based on that, we can estimate the isolation, and see if it will meet the legal requirements.

3. Monolithic slab or stem wall? Not sure if one is better for blocking sound

Personally, I'd go with monolithic slab; it's easier, faster, and cheaper if done right.

4. Architect can design ceiling/trusses with a pitch or different heights which I thought would be good for reducing reflections,

That would not "reduce reflections". It will just send them in a different direction. They will still be strong and specular. So there's no advantage to angling your ceiling from that point of view.

but it will make the resilient channel install more difficult. Is it worth it?

Your inner leaf ceiling is not attached to the roof trusses: it cannot be! The inner-leaf ceiling is attached to the joists for each individual room. This is a studio, not a house or garage, and it is built in a very different manner. There is no contact at all between the outer leaf and the inner leaf (except that the both rest on the same slab). Each of the leaves is an independent structure, with no mechanical connection, So the roof is your outer leaf, and it rests on top of the trusses, with rest on the outer leaf wall. The ceiling is your inner leaf, and it is attached to the joists for each room, which rest on the inner-leaf walls for that room.

5. Considering a drop ceiling (2’ W x 1’H) around perimeter of ceiling for running AC ducts and lighting so I do not lose soundproofing by putting a bunch of holes in the decoupled drywall. Worth the effort?

I don't understand where you'd put in a drop ceiling, or why. It would possibly create a third leaf, or perhaps a resonant cavity, so I wouldn't do that unless there's a really good reason for doing so.

6. Other considerations?

I'd suggest that you buytwo books: "Master Handbook of Acoustics" by F. Alton Everest (that's sort of the Bible for acoustics), and "Home Recording Studio: Build it Like the Pros", by Rod Gervais. The first one will give you the basic understanding that you need to understand how isolation works (as well as all other aspects of acoustics), and the second one will show you how to actually go about building your studio, and all the many ways in which it is very different from building a house, garage, shop, office, etc.

- Stuart -

[ErockLeach]

Thank you for reply!! I'm working on providing more detail, but wanted to clarify a few points:

We're outside of city limits and it's somewhat rural with only one neighbor nearby (120 feet). The base noise level here is around 54-55 DB with occasional peaks around 66-68 DB when a plane is nearby (we're 1 mile from an airport, but we're not under the flight path of large planes). Based on calcs I found online, I think the noise from the studio will be reduced approx. 34 DB from the studio to the neighbor.
http://www.sengpielaudio.com/calculator-distance.htm

Isolation plan: See attached pic of the wall construction. They (HUD) states stucco exterior and 1/2" drywall on resilient channel is rated at 57 STC. If I'm using 2 - 5/8" sheets it should be better than 57 STC, but I have not found this configuration yet. FYI 9-foot ceilings throughout. See page A-7:
https://portal.hud.gov/hudportal/docume ... _16419.pdf

The band is around 105 DB and if the studio wall has 57 STC rating, that should give me 48 DB outside the studio which is already below the average noise level. Given the distance to the neighbor I should be well within my goal with this design for the walls. Still research ceiling design.

Electrical: for aesthetics I would prefer to run wiring behind walls (the end game for the building is an apartment). Has anyone used a product like this? http://www.tmsoundproofing.com/Acoustic ... -Pads.html

Regarding budget: To reduce upfront cost, the kitchen/bathroom/and control room will be part of a future phase but I'm working w/the architect to include piping thru slab/footer, but show bathroom/kitchen as future on the plans.

[Soundman2020]

The base noise level here is around 54-55 DB with occasional peaks around 66-68 DB when a plane is nearby (we're 1 mile from an airport, but we're not under the flight path of large planes).

That's good news. Reasonable levels,nothing overwhelmingly loud.

Based on calcs I found online, I think the noise from the studio will be reduced approx. 34 DB from the studio to the neighbor.

I'd take that with a grain of salt.... there are many other factors that could increase or decrease that. The math is correct, yes, but it does not take into account hings like wind, temperature, focusing effects, reflections from other buildings, etc. I would not count on more than about 20 to 25 dB reduction over 120 feet.

The band is around 105 DB and if the studio wall has 57 STC rating, that should give me 48 DB outside the studio

Nope! That's like saying "I weigh 150 pounds, so if the sun is hot and I run 10 miles, then I'll end up weighing 140 pounds.". There's no relationship. The STC system does not measure decibels, and the numbers don't tell you anything about dB at all. It's just a number. STC-57 only means that when the did a bunch of calculations and mathematical tricks on a graphical curve, that curve was just a bit lower then STC curve number 57. That's all it means.

To calculate STC, the first thing you do is forget all about the bottom two and a half octaves of the audio spectrum and also the top two and a half octaves of the audio spectrum, and you take a series of readings of your sound barrier isolation levels but only in the narrow middle range that is left over. Then you use those readings to draw a graph, then you fiddle with the readings in certain prescribed ways and draw another graph, then you compare your "fiddled" graph against a library of many different "STC" curves. The one that yours comes closest to, without exceeding it. The number on that curve is your STC rating. It's sort of like the "R" rating of insulation: if you have insulation rated R-10, that does not mean it will keep your house 10 degrees warmer in winter. It's just a rating number. All it allows you to is to compare it against other insulation, to see if your rating is higher or lower.

So no, you cannot add or subtract STC ratings from SPL measurements, in the same way as you cannot add or subtract distances in miles from speeds in kilometers per hour: they are two very different things, only very vaguely, and very distantly related to each other.

If you have a sound level of 105 dBC on one side of a wall that is rated at STC-57, the sound level on the other side could be anywhere between about 50 dB and about 90 dBC: There's no way to know, unless you actually measure it, and it depends absolute on the frequency spectrum of the sound. If it is just people screaming at each other with their natural voices, you might well get a reading of only 50 dBC on the other side, but if it is typical "smiley face" EQ'd bass-heavy rock music, you might see 80 or 90 dBC on the other side. It's impossible to know, without measuring how well that wall really isolates across the entire spectrum.

if the studio wall has 57 STC rating,

That's another big issue: Doing just one wall to STC-57 is pointless: the entire room has to be done to STC-57 rating. That includes all of the walls, and the floor, and the ceiling, and the windows, and the doors, and the electrical system, and the HVAC system. If any of those is not up to STC-57, that that means you wasted a whole truckload of money on doing some parts to STC-57! For example, if all your walls are STC-57 but your ceiling is only STC-45, then your entire studio is STC-45, and you poured a lot of money down the drain on the all the STC-57 walls: You could have just made those STC-45, ad still gt the same total outcome. The overall isolation of the studio is only as good as the weakest part.

In other words, you have to design the isolation such that ALL parts of the studio are up to the same level, whatever you decide that level is. If you want to have STC-57 walls, then all of your doors also need to be STC-57. That's a tall order. It's pretty easy to build a wall that gets STC-57, but a hell of a lot harder to build a door that gets STC-57...

should give me 48 DB outside the studio which is already below the average noise level.

Even if you did only get 50 dB on the other side, and the ambient level is also 50 dB, you'd still hear it without any trouble. It would be very audible. The human brain/ear has an amazing ability to pick out quiet sounds from among louder sounds. have you ever been to a noisy part, or even just a busy restaurant, where the ambient level is really loud, but noticed you can easily pick out individual conversations and voices, even from people who are not standing close to you?

If you have an ambient level of 50 dB, you'd need to get your own levels down to about 40 or even 35 dB to make them inaudible. Your brain can pick out patterns and sounds that are as much as 16 dB quieter than the ambient sound. Ever noticed that you can hear the drum beat from a night club a long distance away, even when there's traffic noise around you?

for aesthetics I would prefer to run wiring behind walls

You can do it that way with multiple penetrations any putty pads behind, but you are creating a situation that can be avoided: you are creating many potential points of failure in your isolation system. Why risk it? If any one of those fails for whatever reason you trash the isolation of the entire studio.

Also, I'm not sure what you have against the aesthetics of surface mount raceways, as some of them can look pretty good, and they are often used in offices thee days, and even in some apartments.


- Stuart -

[ErockLeach]

I'm getting ripped a new one here!! lol, thanks for the correction on STC vs dB...learning as I go.

The county sent me their residential sound limits (attached). From what I've read & experienced the lower frequencies is the problem area. For the lower frequencies, the sound limits are in the upper 60s dB range. Based on 20-25 dB drop for 120' distance to the property line means I need to be no more than approx. 87-92 dB outside the building. So...for a band at 105 dB, I need 13-18 dB reduction from the wall. I'm having a hard time finding rep's or sources online if my wall design is enough or too much.

My wall design is similar to attached but with 2 - 5/8" drywall

-Soundproofingcompany.com recommended their IB-1 clips with hat channel
-Green glue company recommended their whisper clips, but green glue in between layers of 5/8" drywall.

[Soundman2020]

I'm getting ripped a new one here!! lol, thanks for the correction on STC vs dB...learning as I go.

Sorry about that! Once I get my "rant mode" triggered, I do tend to go on a bit, and it really isn't about you personally! I just like to pour out lots of info in general on some threads, so everyone gets the benefit...

The county sent me their residential sound limits (attached). From what I've read & experienced the lower frequencies is the problem area. For the lower frequencies, the sound limits are in the upper 60s dB range.

That's a really high limit! For most residential areas these days, the limits are set ridiculously low, at 45 dBA or some such. Which is impossible to achieve. Just waking down the street and quietly talking to the person next to you would exceed that. So 60 dB is very generous. Lucky you! I must admit, I'm surprised.

However, do check the fine print. Many regulations have a tiny little "covering our backs" clause in there, that says something like: " ... or any objectionable sound of any type, regardless of measured levels. Of course, the meaning of "objectionable" is never defined, so they can make it mean whatever they want it to mean, for each individual case...

That said, I'm looking at the table you posted and not seeing that it says your overall limit is 60 dB. From what I can see on that table, your overall limit is, indeed, around 45 dBA. I would use that as your reference number.

Based on 20-25 dB drop for 120' distance to the property line means I need to be no more than approx. 87-92 dB outside the building. So...for a band at 105 dB, I need 13-18 dB reduction

You can get that from a cardboard box! Well, not quite, but close! An inch of corrugated cardboard would do it... 13 dB reduction is nothing at all.

I'm having a hard time finding rep's or sources online if my wall design is enough or too much.

For a single-leaf wall (which is all you need if you only want 13 dB of isolation, the empirical Mass Law equation is fine:

TL= 14.5 Log M +23

Where: M is the surface density.

For two-leaf isolation, it's a bit more complex.

My wall design is similar to attached but with 2 - 5/8" drywall
-Soundproofingcompany.com recommended their IB-1 clips with hat channel
-Green glue company recommended their whisper clips, but green glue in between layers of 5/8" drywall.

There's a limit to what you can get with resilient clips. I would really suggest that it would be better for you to do proper decoupled two-leaf walls and ceiling.

- Stuart -