John Sayers' Recording Studio Design Forum Archive

Whew, here goes:
This forum is a bit intimidating for an amateur. I've tried to read the rules and the FAQ's, and frankly even some of those are over my head. Here is my space and here are my goals, please bear with me:

Space:
It's in my profile, but I'm in Springfield, IL. If someone is close by and knowledgeable, I'd certainly consider paying for a consult. I bought a 1940ish construction 2-level home with an unfinished basement, and I want to semi-finish half of the basement into a recording studio. See below regarding needs, but I'm an amateur/hobbyist, and I don't need a perfect solution. I mostly want to make passable nonprofessional recordings without waking up my kids. The basement is unfinished, and the HVAC systems are pretty much dead center in the basement. If I use "half," which is kinda my intention, it's about 21x12, without wrapping around the HVAC bundle in the middle. Cinderblock walls, cement floor, electrical/cable/plumbing running up in the joists, minimal but not zero moisture.

Dimensions are approximately:
21' long, 12' wide, 7' ceiling to the bottom of the joists. No obstructions in the middle of the space. There are areas in the corners in which HVAC conduit comes down another 8". On the long exterior wall near a corner, there's plumbing that is related to an outdoor sprinkler system, and we'll need to maintain access to it. On the long interior wall near the opposite corner, we'll likely need at least a small access panel or something similar to be able to get to humidifier/controls for one of the two furnaces.

Needs:
I'm mostly a guitarist and hobbyist home recordist. I mostly make music on my own, and therefore I don't think it makes sense for me to try to make separate control/live rooms - plus it's a small space anyway. I want to be able to record guitars and similar acoustic/amped instruments with decent results, but I don't intend to be playing through a Marshall stack or anything. A 12W princeton cranked to 6 or 7 is about as loud as I anticipate a guitar getting. As noted above, I'd like to be able to play with the volume at 4 or 5 at night without waking my kids 2 floors above. I do have a drum kit, though I'm not a drummer. This would be used occasionally during daytime hours, so I'd like it not to be a tremendous nuisance to the rest of the house, but it doesn't need to be inaudible. I occasionally record with 1 or 2 friends, but again, we're talking low wattage guitar/bass rigs, maybe keyboards or an upright piano someday, electronic drums and occasionally miking up a kit. I sing too. You don't want to hear it.

I unfortunately don't have a lot of time to do the work my self. I'm hiring a contractor who mostly specializes in additions/renovations. He seems pretty competent, and has at least some working knowledge of basic absorption/reflection principles, but by no means an expert. I'm going to need to guide him and prioritize what's most important. In our current conversations, we've discussed:

-Bats of rockwool between the ceiling joists, and a drop ceiling. I know there are some acoustic issues with these, but there's all kinds of electrical/plumbing over hear that I don't entirely know what it is, and it seems like a good idea to leave easy-ish access. Bad idea? With the rockwool up above, does the choice of acoustic panel really matter?
-Framed walls with moisture barrier and insulation to-be-determined. Recommendations for this? Drywall on resilient channel.
-Probably some type of glued LVT flooring
-Not sure what to do with HVAC (there's one send and one return directly off ductwork communicating with main house system. This may be the hardest thing to address. My contractors suggestion was to make these a long, serpentine run of multiple 90 degree angles, but I'm skeptical. Thoughts on this?
-Once constructed, I'll need to come back and look for some advice for acoustic treatment, but if there are things I need to consider straight away, by all means, bring them up.

What am I forgetting/leaving out? I know you all probably require some more detail. Just let me know.
Thank you all in advance.

Shawn

Hi Shawn!

Welcome to the forum!

Here are a few things to start your journey:

http://johnlsayers.com/Recmanual/index.htm Read all of that and you'll have a better idea of what is involved in obtaining your goals.

I've never owned a home with an even slightly damp basement so I'm not sure why yours is or how you would address that. But I feel like it should be #1 on your list of things to address.

You're talking about putting insulation in your joists with a dropped ceiling. Those are things that do more "acoustic treatment" rather than "sound proofing". It seems like the most important thing to you is not bothering your children or other people in your house while you're creating your music. Sadly, sound proofing is where most of your money and room size will be eaten up. In order to sound proof a space, you need to make it air tight. Furthermore, you need to avoid flanking. Flanking can be thought of as short circuiting, or easier yet, just touching. Basically, you will need two leafs. The inner leaf which is the studs and drywall of the room you will be working in. Then you'll have an air space filled with cheaper fluffy insulation. Then, you'll have your outer leaf which again, is studs or joists and more drywall/or subfloor. All of that is what allows the reduction of sound transmission. After you have a sound proof room, chances are it won't sound awesome inside, yet. From there, you can add all sorts of treatment to make it sound better.

Sadly, you have a short ceiling. Good thing you aren't trying to achieve a pro-level studio with that height because it would maybe be impossible to get an amazing sounding room with that characteristic. But chances are, you can get something that sounds decent. You will DEFINITELY want to build an inside out type construction for your ceiling!

I don't entirely follow your description of where things are in your basement. I know you don't have much time, but you will need to find some time to learn the basics here so you don't waste money building something that quite literally does nothing to improve your current situation and certainly won't fulfill your needs. Having said that, the BEST thing you can do is to download SketchUp Make. You will have to google it to download the latest one they made. It's kind of discontinued but it's the best free one you can use as their new "free" version uses an internet browser and it is slow and less capable. There are lots of great youtube videos to show you the basics. One major hint I can give you is to create "components" for each item (like a piece of drywall) you make. Then assign it to a layer (like, inner leaf drywall). Also, look up "constraining". It's pretty easy after that.

SketchUp your basement. Check out https://amcoustics.com/tools/amroc and you can find the best room dimensions for what you need. With that 7' ceiling, you'll be limited, but again, do your best to not have a BAD ratio. From there, you can start laying out that room in your basement. Remember, you'll have to build a "room in a room" to achieve the best sound proofing. 12 watt amps are loud and drums are REALLY LOUD. You need to figure out how much isolation you need. Buy a sound level meter from your local music store or in a pinch, get the "audiotools" app for your phone (it's like $20 or so) and measure upstairs with your meter set to slow and C weighted. Now play your drums and see how loud it is upstairs. The difference between the two volumes is how much isolation you're after. From there, you can determine how intense your sound proofing has to be. You might be able to get away with one layer of 1/2" drywall or you might need to beef up your subfloor (from below) and use three layers of 5/8" drywall with green glue.

A sound proofed room = air tight = proper ventilation. Proper ventilation = real estate and being annoyed hahaha
Now that you've built a room that meets your dB requirements, you need to ventilate it and maintain the sound proofing. In order to do that, you can't create flanking by having an air duct touch both your inner and outer leafs. Also, you need to add HVAC silencer boxes. To summarize the task, figure out how many and how big of ducts you need for the supply and return of your room(s). cubic feet and how many times your need the air to be cycled per hour will get you in the ball park. From there, figure out the cross sectional area of the duct. Make a box (you can find some threads on the forum here about them) that is the same surface density as the wall that you're penetrating. The box has twice the cross sectional area within it and leaving it. Calculate the speed of the air flowing through your system. The slower, the better. There are also threads about this you can read. So basically design your system so that it adequately heats and cools you, maintains your surface density/sound proofing, and is quiet enough (slow moving air). These boxes are quite large, so your SketchUp will help you find where they can go.

If you have any windows, they could be a weak spot to your sound proofing, so you'll have to address those. Also, doors are typically your weakest link. If you have a wall with great transmission loss qualities but have a crappy regular door on it, you've wasted your time and money. Your door properties must match your walls. So, no different than walls, you'll need mass, space and mass. So, a solid core door, space and then another solid core door. Air tight room = great rubber door seals as well.

If you're concerned about hum in your audio path (which you should if it's an old building), consider running your electrical outlets with what is called a "star ground". You can find lots about this on google and on threads here in the forum. I suppose, even if you ran your critical outlets that you use for your gear with the star ground, that's better than running none. For lighting, run it on the opposite leg of your electrical panel than your audio/electrical outlets for your studio room(s).

Acoustic treatment: There is lots to this if you really want to get into it. And there are very minimal things you can do to make HUGE improvements. Again though, it sounds like sound proofing was your biggest concern so you should maybe get that side of things sorted out in SketchUp and then look at sound proofing. Just know that you should maybe realize that you'll lose 4"-12" of any given wall surface to apply treatment. That's why I suggested to use the inside-out method for building your ceiling as it saves all of that space.

There is lots more to it, but you'll learn that as you start your design. You'll have questions I'm sure. Hopefully you can find most or all of the answers to your questions on the forum, but if not, ask and one of the pros or a noob like me might even have the answer.

Anything you learn here, show your contractor and watch his every move to make sure he builds everything correctly. If he cheats on any areas, it could severely compromise how effective the system is which would be a waste of your money.

Don't start building anything until you have a plan on SketchUp that you've thought out thoroughly and have shared here on the forum for people to review for you.

Get designing your perfect space and share your SketchUp files with us so we can help you out!

Greg

Greg - Thank you so much for the detailed response. I do recognize that isolation and absorption are different, but I think my technical comprehension of where these things overlap or do not overlap is poor.

A few additional questions and practical considerations:
1) Regarding the ceiling: Is there a way to achieve a reasonable/acceptable degree of soundproofing whilst still leaving a reasonable access to the wiring/plumbing that are up in the joists? That's really the reason I was considering a drop ceiling. Along these lines, I acknowledge that a "room within a room" design would be best, but if I understand correctly, this would require construction of a framed ceiling resting on the framed walls, not touching the floor joists above. This seems like it would cost at a minimum about 3" of overhead space, which is obviously at a premium already. Is there an acoustically acceptable means of achieving a "drop" ceiling that is still attached to the floor joists above via clips, furring/hat channel/resilient channel or some combination thereof? If so, it seems to my uneducated mind that this would still achieve the mass/space/mass idea via the drop tiles (of course, less massive than double layer drywall), the gap between the tiles and joists (as well as the rockwool between the joists), and the subfloor above. But chances are good that I still don't fully understand this. I guess there is really no "seal" in this design. Are there diagrams for this somewhere to which I could refer my contractor?

2) I have additional questions about HVAC issues, but I'll have to return another night with those!

thanks again.

Shawn,

I got a lot of value from buying and reading (and trying to comprehend as best i could) Rod Gervais's home recording studio construction book. It does a really nice job of giving the theory, application, and options for each element of studio construction without having to bounce from thread to thread. Once you digest that, the things on here make a lot more sense and you can get targeted with your questions.

In the meantime, sketchup or something similar helps everyone here help you, and it helps visualize your space in a way you can't really do without a 3d modeling program like that.

As far as the ceiling goes - you really can't isolate the basement without doing a second non-flanked ceiling construction (ie, drop ceiling just won't cut it). However, you can do it [u]without[/u] a separate set of joists sitting on inner framed walls. My studio has a different ceiling assembly in each room - the control room has an independently framed ceiling since that's where most of the noise will be. The iso/tracking room used resilient channel channel and the appropriate clips due to issues with a load bearing beam and existing hvac that you mention.

2 layers of drywall is ideal, but that does take more height away from your celing, and you'd be down in the 6'6" after you got the clips and drywall put in - and that is pretty low to work with.

I've included some photos of my celing/wall assemblies.

The LAST thing i'd ask you to research is your vapor barrier situation. The idea of a vapor barrier is to keep moisture from inside your sealed-up studio from condensing on your framing and insulation and causing rot. But guess what...our basement walls leak moisture as vapor the other way, and then can get stuck behind there too.

So you get water from exterior walls and moisture from people inside and you'll end up with mold either way. My research concluded that it might be better to use semi-permeable rigid insulation to allow more breathing of the vapor. Essentially, it is the rigid styrofoam-type stuff. - so that goes on the walls, the wall assemblies use sound-attenuating clips to attach to the outer walls, and then un-faced insulation goes in between.

I was definitely in your shoes at one point - it is overwhelming. I guess just take it one step at a time. Here's hoping it doesn't take you ten years too!

-Jon