Which of these two popular soundproofing structures is right for you? Whether you’re working on the ultimate home theater, an in-house recording studio, or you just like to party it up with your friends on a weekend, unless you’re happy making enemies of your neighbors, you’ll need to engage in a spot of soundproofing.
There are plenty of items you can add to a room to kill off soundwaves, such as thick curtains and acoustic foams, but before you bring in any extras, it’s important to focus on the general structure of the room.
Acoustically treating the walls of a room is far more effective than using sound dampening accessories alone. Then, when you combine them, well…let’s just say the Christmas card from the neighbors won’t contain death threats.
When it comes to soundproofing walls, you have two options to choose from, a staggered stud structure, and a double wall. In this article, I’ll be sharing with you the pros and cons of each soundproofing method, so you can decide which is right for your home.
*Whispers in ear*…Are you ready to get silent?
What Is A Staggered Stud Wall?
A normal wall is composed of two sides connected by a central structural network of studs. Traditionally, each stud touches both sides of the wall, which is a problem for us noisy nuisances, as it offers the perfect bridge for vibrations to travel from the inside of the wall, through to the other — cue an angry knock on the door from your neighbors.
In a staggered stud wall, the studs are decoupled, meaning they only ever touch one side of the wall. Rather than dancing their way through the wall, sound waves dive off the end of the stud like lemmings, directly into a blanket of foam or fiberglass insulation — nice!
Before we move on to the double wall soundproofing method, let’s take a look at an illustration of a staggered stud wall, just to give you a better idea of how it works…
…A thing of beauty, to be sure. Those pesky soundwaves don’t stand a chance!
What Is A Double Wall (Double Stud Wall)?
A double wall is named so because it’s essentially composed of two standard wall frames joined together. For every individual stud in a traditional wall, there are two in a double wall.
Now, I know what you’re thinking…surely it doesn’t matter how many studs there are if they still form a bridge that sound waves can travel over. But here’s the thing…the studs never touch one another.
Rather than fixing the dual 2×4 studs together, they’re held in place by the bottom and top plate, leaving a small gap in between each frame. In this gap is nothing but sweet, sweet, slow-moving air, which you can basically think of as a sound graveyard!.
Better still, you can fill it with a high density, closed-cell insulation spray or some other form of mass-based insulation — good look wriggling through that, sound worms!
Let’s bring this section to a close with another handy visual aid…
…That’s the general idea. Now picture all those gaps filled with insulation, and you’ve got yourself a seriously silent structure on your hands.
Staggered Stud vs Double Stud Wall for Soundproofing — The Head-to-Head
I’m aware that we’re all busy people, and you may not have time to take in my full article, so I’m going to lay it out for you straight right now…cards on the table.
When it comes to soundproofing, the most effective structure is – quiet drumroll, please! – the double stud method!
So, if you’re after the quietest possible room you could create, you should absolutely go with double walls. However, there are a few drawbacks to the double stud structure, which is why, if you’ve got the time, I implore you…read on.
STC stands for Sound Transmission Class. It’s the standard metric used for measuring the efficacy of a soundproofing material or structure. The higher the STC score, the more soundproof something is.
So, how do these walls stack up against one another in terms of pure sound killing potential?
Staggered Stud Walls
Assuming a double stud wall is built using two ⅝-inch layers of gypsum, one of either side of the studs, you’re looking at an STC of 48.
To put that in some context for you, loud conversational speech is completely inaudible through an STC 45 structure. At STC 50, most loud bass frequencies in music disappear, leaving online faint remnants of the mids and trebles.
38–42 is considered fantastic residential soundproofing, while 50–65 is considered professional-grade soundproofing, the likes of which can be found in commercial recording studios.
So, as you can see, staggered stud walls fall right in the middle here. They’re great for a residential property, but not quite muted enough to qualify as professionally soundproofed. They’ll kill off almost all conversation (great for privacy), but loud music will still penetrate the outer panel.
Double Stud Walls
Applying the same dual ⅝-inch gypsum panels to our double stud wall, we get something more to the tune of STC 60, which is at the higher end of professional-grade soundproofing — pretty impressive, right?
There are very few sounds that can penetrate an STC 60 structure. They’d have to be extremely loud to even register faintly on the external side of the wall, which means – as I said earlier – in terms of pure soundproofing muscle, double stud walls are our winner!
STC Ratings After Mass and Damping Treatment
It’s important to bear in mind that those STC scores aren’t universally exact. The sound dampening ability of each class of wall will differ depending on widths, insulation types, and the orientation of the room. So, what happens when we introduce some more variables?
Side Note – I decided to use drywall for mass, and the infamous soundproofing solution, Green Glue, for damping, to continue this comparison.
Staggered Stud Walls
If we introduce some drywall into the staggered stud equation, we can achieve a very respectable STC 58, which is just shy of optimal professional-grade soundproofing. Not bad…not bad at all, but what if we really kick this soundproof trifle up a notch with some Green Glue between the gypsum panels?
Once the green glue is applied and set, we’re looking at an STC of 62, which is fantastic! That’s better than the average professional soundproof environment. Suddenly, a staggered wall doesn’t seem like such a bad idea.
Double Stud Wall
Adding nothing else into the double stud mix but some drywall, that initial rating of 60 skyrockets to STC 68, which is certainly nothing to scoff at. And squeezing in some Green Glue takes things to whole new levels of silence, with the wall reaching STC 73.
Of course, as the double stud wall was more impressive when it was pretty much hollow, it was always going to remain the more impressive option once insulation and damping materials were introduced.
However, the soundproofing efficiency of a wall isn’t our only consideration. To give us a more holistic idea of what we’re dealing with, let’s break these walls down with a couple of classic pros and cons lists.
Staggered Stud Walls for Soundproofing — Pros and Cons
- Space-Friendly – Staggered stud walls take up considerably less room than double walls.
- Inexpensive – Staggered stud walls require fewer materials than double stud walls.
- Energy Efficient – Staggered stud walls don’t just prevent noise from escaping, but heat too, so they’ll save you a few bucks on the old energy bills — hurray!
- STC Score – Staggered stud walls aren’t quite as efficient as double stud walls when it comes to soundproofing.
Double Stud Walls for Soundproofing — Pros and Cons
- STC Score – Double stud walls are absolutely the most effective way to soundproof a room.
- Energy Efficient – Much like staggered stud walls, double stud walls do an excellent job of keeping the place nice and toasty!
- Imposition – As they’re composed of two discrete wall frames, double stud walls take up a significant amount of space, leaving you with less wiggle room.
- Expensive – Double stud walls require more materials, so they can work out pretty pricey.
Staggered Stud vs Double Wall for Soundproofing — Which Should You Choose?
Up until that pros and cons round, it really seemed like double stud walls had the edge, but the amount of space they eat up is a serious drawback. You can expect to lose roughly 4 feet from both the breadth and length of your room, which is pretty rough.
I’m currently working on building a recording studio, and I need room for A LOT of equipment and instruments, so this shrinkage is a real dealbreaker for me.
Even if you’re only building a home theater, a double stud wall is still going to shove all your furniture towards the center of the room, which may make things a little claustrophobic.
A staggered stud wall nibbles a small amount of space, but that’s just it…it takes up a small amount of space. If you installed four, you’d only stand to lose around 10 inches in the length and breadth of the room, which is just shy of 2-foot.
Combine the space-saving superpowers of staggered stud walls with the fact that you can still achieve STC 68 with proper mass and damping installation, and they become a much more practical option. And that’s not even factoring in the money you stand to save on materials.
Ultimately, though, it all comes down to whether STC 68 is suitable for blocking out the kind of noises you wish to make in the room.
The STC scale is based on a speech-spectrum source, so when it’s applied to intense noise sources such as, say…a full rock band with their amps cranked, it’s not always too accurate.
Even though the STC 73 score of the double stud wall seems like overkill for residential soundproofing, that excess may actually be just the ticket for eliminating the transmission of booming noises.
The Verdict – If you’ve got the money and the space to spare, take the double stud route, but if space is more valuable to you than gold, staggered stud walls are the smarter choice.
Granted, STC 68 perhaps isn’t what it’s cracked up to be when things get really loud, but it will still be enough to maintain a liveable environment for your neighbors, which is the name of the game, folks!
Before we go our separate ways, I thought it would be a good idea to discuss a few key pointers that have helped me in my own soundproofing ventures.
- Try to identify the weakest areas of the room in terms of sound dampening, so you know where you’ll need to do the most work.
- Before you break ground (or wall, in this case), make sure to check your local building code. Installing 24-inch framing walls is not permitted in some areas.
- More insulation isn’t always a good idea. It needs to be loosely packed, otherwise, it will become a medium for vibrations to travel through.
- Only use lumbar if it has been pressure treated.
- Don’t neglect your ceiling and floor. They will also need to be acoustically treated.
- Use a quality sound-dampening caulk such as Green Glue to seal gaps above and below the drywall.
- Don’t forget to treat your vents, doors, and windows. Invest in some sound barrier curtains and some foam weather strips.
Staggered Stud vs Double Wall For Soundproofing — Summary
There you have it, fellow noisemakers; if you want the ultimate acoustically treated room, you should use the double stud technique, but be prepared to feel like the walls are closing in on you.
If you’re happy with really strong, albeit inferior, soundproofing as long as you retain most of your space for stretching out, throwing shapes, and storing all your stuff, then staggered stud walls are a no-brainer!