If you want to get the most from your home theater system, you must sound treat your room. Without proper acoustic treatment, the booming bass will easily dominate the experience. This is where bass traps come in to save the day.
What Is a Bass Trap?
A bass trap is a type of acoustic treatment optimized to absorb low-frequency sound (bass). They’re essentially a specialized sound panel. The most common type of bass trap is the porous absorber, which is made of acoustic foam or other foam-like materials like fiberglass or mineral wool. Bass traps come in various shapes and sizes, but some of the most common are triangular and wedge-shaped corner traps designed to be placed in the corners of your room. More on that later.
While you might associate bass traps with professional recording studios, they can be priceless assets for your home theater. As their name suggests, bass traps absorb bass so that it stops reverberating around your room. Although reverberation can technically happen with any frequency, it’s especially noticeable with low frequencies.
This is because bass frequencies have long wavelengths and can reflect off walls, the ceiling, and the floor multiple times before eventually losing energy and decaying. The end result is a boomy, undefined bass that detracts from your movie night. Bass traps significantly reduce or outright prevent this unwanted build-up by absorbing excess bass, meaning you only hear the bass as it plays through your subwoofer, without any added echoes or reverberation.
Bass Traps Are a Must for Smaller Rooms
Bass is omnidirectional, meaning it travels in all directions from the source. You can’t point it at your couch like you’d do with speakers, which inevitably leads to a build-up in one area and a dead spot in another. Dead spots occur when bass reflects off a surface, resulting in the waves canceling each other out, a phenomenon known as destructive interference. You’d think that adding bass traps would simply reduce overall bass, but it actually improves bass response throughout the room.
These issues are particularly prominent in small and medium-sized rooms. Unless you’re placing your subwoofer against your couch, that is. All the walls in a small room are close to the subwoofer, resulting in particularly strong reflections and standing waves.
By adding a few bass traps, you’ll create a smooth and balanced bass response for your home theater. Don’t worry about the traps making your room sound “dead.” You’ll still get all the action from the subwoofer—it’ll just sound better.
The Type and Placement of Bass Traps Matters
There are two main types of bass traps: resonant and porous. Resonant bass traps like Helmholtz resonators made of brass are fairly uncommon and difficult to set up. You’ll mostly come across the typical porous type, so that’s what we’ll discuss.
Much like subwoofer placement, the location of your bass traps affects the end result. The most common piece of advice you’ll hear for bass trap placement is to put it in the corners of your room because that’s where low frequencies tend to build up. Ideally, you want to cover the whole corner, from the floor to the ceiling, to maximize bass absorption.
However, the counterargument to corner bass traps is that the whole wall causes the issue, so focusing on just the corners means you’re only accounting for those parts of the wall while ignoring the rest. To get complete coverage, you should treat your entire room the proper way by testing where low frequencies accumulate and prioritizing those areas, either using your ears or dedicated room correction software.
If you’re in doubt, just focus on quantity. Add as many bass traps as you can comfortably fit into your room. Cover all corners, walls, and ceiling. The practical limit is when your spouse yells at you for filling the entire living room with 24 bass traps. You’ll have enough bass absorption to justify the jump to 5.2 surround sound!
Leave a two-inch gap between the bass trap and wall to significantly improve its bass absorption.
By the way, while bass traps prioritize absorbing low frequencies, they also absorb mid and high frequencies. This essentially means that by installing bass traps, you’ll enhance room acoustics as a whole.
Bass traps are likely the most important asset in your sound treatment arsenal. With a few strategically placed bass traps, you can greatly improve the acoustics of your home theater setup. Don’t miss the chance to enhance your movie nights and TV shows.
