Creating a studio-quality acoustic space involves two distinct processes — soundproofing and acoustic treatment. Soundproofing — more accurately called sound isolation — not only prevents offensive outside sound from entering your space but also prevents loud sounds inside your studio from leaking out and disturbing family and neighbors. Acoustic treatment involves maximizing your existing space by analyzing the geometry of your room (wall dimensions and angles) and absorbing or diffusing problem frequencies to achieve a balanced sonic environment. Learn more about improving the sound of your space in this article, How to Make Your Recording Space Sound Great by Mitch Gallagher.

It’s important to keep in mind that these are two different design concepts that address different issues. Soundproofing doesn’t change the acoustic character of your room, and acoustic treatment does nothing to actually soundproof a room — but both are vital elements in creating a professional listening and recording space. This article will give you a basic overview of soundproofing techniques and help you decide the best way to approach your own prospective studio or rehearsal space.

Soundproofing means construction

If your goal is to sonically isolate your studio or rehearsal space as much as possible, you will need to approach it like a construction or remodeling project. As you’ll learn, effective soundproofing cannot be achieved simply by hanging enough sound absorbers on your walls. Projects like applying sound barriers to drywall and building a floating floor involve tools and skills that you may or may not have. We’re here to help you understand some basic soundproofing concepts — when you’re serious about tackling a soundproofing project, it would be wise to consult with a contractor, preferably someone with knowledge of studio construction. If you choose a contractor who knows nothing about acoustic engineering, their expertise in construction techniques will be valuable, but they may cut corners that will defeat the design or plans. However, if you can clearly explain to them what you’re trying to achieve and repeatedly stress the importance of isolating the two spaces, then they should be able to use their know-how to effectively incorporate sound-isolation materials into their construction methods.

Minimizing sound leakage — floor, walls, and ceilings

If you’re trying to sonically isolate a room, then it’s logical that you need to deal with the room’s boundaries — floor, walls, and ceiling. Without getting into the deep science of it, soundproofing is basically achieved in two main ways — by added mass and air gaps. Mass means that the denser a material is, the less sound energy will be transferred through it. Air gaps — like building a wall comprised of two layers of drywall separated by a small distance — are also hugely important when trying to achieve true sonic isolation. With mass and air gaps in mind, let’s take a look at some ways to approach soundproofing your walls, ceiling, and floor.

Floating floors

The most common technique for soundproofing a floor is to construct a floating floor. This is a smart place to start before dealing with your walls and ceiling — work from the ground up, as they say. Whether you’re in a basement on a concrete slab or on an upper floor of a house, the concept is the same — either “float” the existing floor materials (frequently impossible or financially unfeasible to do in an existing structure), or add a new layer of flooring that is decoupled from the existing floor. “Floating” refers to decoupling the floor from the surrounding structure using hard rubber pucks, or Auralex U-Boat floor floaters (we like using U-Boats because their shape allows them to efficiently deaden both vertical and lateral vibrations).

If you want to float an existing floor, you’ll need to get down below the existing subflooring right to the joists, install U-Boat floor floaters, and then replace the subflooring, underlayment, and flooring materials. Using an underlayment material that is effective at preventing sound transmission, like Auralex SheetBlok, is a smart move too. You could also frame a false floor (essentially a wooden riser) and install that atop the existing flooring with isolators placed beneath it. This is only practical if you have high ceilings, as raising your floor even a few inches can make your room feel much smaller.

Left: Auralex U-Boat floor floaters are used to decouple flooring materials from the surrounding structure. Right: Auralex SheetBlok is a dense, thin material that is applied to drywall to drastically reduce sound transmission.

Isolating walls

However you decide to deal with your floor, your walls are the next step in your soundproofing endeavors. Assuming you are dealing with typical drywall construction, you’ll want to be familiar with Auralex SheetBlok. It’s an ultra-dense material that is about 6dB more effective than solid lead at preventing transmission of sound. SheetBlok is designed so that you can adhere it directly to a sheet of drywall, dramatically enhancing its sound-stopping capability. Using a solution like the Auralex RC8 Resilient Channel makes it easier to create a SheetBlok sandwich — these wall spacers can support up to two layers of 5/8″ drywall, plus a layer of SheetBlok in between. They’re designed to support the additional weight and also serve to help decouple the walls from the surrounding structure.

The Auralex RC8 Resilient Channel offers a better, more reliable way to attach drywall and SheetBlok for your walls and ceiling.

If you have a large enough room to sacrifice a few inches all around, you could add another layer of drywall and SheetBlok spaced away from the existing wall to create an air gap (essentially building a second wall, similar to the framed false floor mentioned above — for true isolation, this second wall would be built on top of the isolated floor structure). This is a more advanced maneuver that would likely require some professional help, but the isolation provided is extremely impressive. At this point, you’re basically building a room inside a room, a most effective technique that many world-class recording studios employ.

NOTE: Adding hundreds or thousands of pounds of building materials inside an office building or residential structure should only be done with the approval/supervision of an architect or qualified contractor. Adding this much weight to a second-floor bonus room or over-garage space above a non-load-bearing structure could prove to be disastrous.

Soundproofing your ceiling

The same rules apply for your ceiling as your walls and floors — sound isolation is achieved by adding mass and introducing air gaps. The ceiling can be one of the most challenging parts of a DIY sound-isolation project — hanging drywall on walls is tough enough, and doing an entire ceiling is even more challenging. The theory is the same as walls, though — you can create a SheetBlok/drywall sandwich and hang that from your ceiling with the use of Auralex RC8 Resilient Channels.

Depending on your situation, it may be more practical to consider the floor above your ceiling. Refinishing the floor above your ceiling with a layer of SheetBlok and perhaps some cork underlayment could make a big difference too, although that’s not always practical. It’s also worth considering insulating the space between your ceiling and the floor above with glass-fiber insulation. Adding mass and introducing air gaps in your ceiling structure is a challenging task but will go a long way toward creating a sonically isolated space.

Auralex Mineral Fiber insulation is sound rated to reduce sound transmission through walls and ceilings.

Other considerations for sound isolation

Auralex StopGap is an acoustic sealant to reduce sound leakage around wall outlets, windows, and other small air gaps.

Besides your floor, walls, and ceiling, there are numerous things you can do to improve the sonic isolation of your space. One of the simplest things you can do is use an acoustic sealant such as Auralex StopGap to seal around wall/floor intersections, electrical outlets, windows, and any other small air gaps that may be present in your studio. By keeping in mind that anything that leaks air will leak sound, you’ll probably be able to identify and seal problem areas relatively easily.

Take some time to look at your options for doors and windows — both are available in sound-rated models. Windows with double-pane, laminated glass do well at reducing sound transmission. Sound-rated doors are available too, and a popular technique is to hang two doors back-to-back on the same jamb, separated by a small air space. Doors with more mass (solid-core doors, not Lauan sandwich-core doors, commonly used in contemporary construction) that are weather-stripped offer superior isolation but may require improved hardware (more hinges) or even a heavier-duty doorframe to hold up their weight.

One thing to consider that is often overlooked is upgrading to the quietest HVAC system available to you. Even with the rest of your room decoupled from the rest of the building, you need ventilation, and the sound of your HVAC (heating/ventilation/air conditioning) system turning on will instantly ruin your sense of sonic isolation. While this is one aspect of your studio or rehearsal space that should definitely be left to professionals, it’s also one of the most important sonic considerations.

Not a weekend project

Once you understand the principles of isolating a studio space, it’s clear that this is a major project. And obviously, all soundproofing measures must be in place before you start working on acoustic treatment, let alone installing all your gear. It’s best to tackle a sound-isolation project all at once, even if it means weeks of work.

And as you tally up contractor costs, material costs, and the time spent on the project, a sound-isolation project can quickly become an expensive proposition. That’s actually one of the reasons it’s so important to seek professional advice and use sound-rated materials at every step — cutting corners or using substandard materials will not only reduce the effectiveness of your isolation, but you’ll also end up spending more money in the long run as you try to fix issues in the future. In other words, if you’re serious about achieving as much sonic isolation as possible, do it once and do it right.

Are you planning a soundproofing project in your home or studio? Your Sweetwater Sales Engineer can work with you along the entire process, even if it’s months or years down the road — give us a call anytime at (800) 222-4700!