We’ve talked before about the inherent problems that typical home studios encounter in rooms intended as bedrooms. The problems come down to reflective parallel surfaces bouncing sound waves around the room in such a way that the audio coming from monitors gets beat to sonic pulp, making everything you hear from them questionable. Secondly, recording sounds in such a room means that the signal arriving at the microphone is also compromised.
The Ultimate Acoustics Acoustic Bass Trap Bevel Design is the fourth element of acoustic treatment we’ve reviewed recently, the other three being:
- Auralex Acoustics MoPAD Monitor Isolators — to prevent monitors from transmitting vibration to desks and speaker stands.
- Primacoustics VoxGuard VU — for shielding a microphone from room reflections.
- Primacoustics London 8 Room Kit — to break up primary reflections, allowing monitor audio to dominate sound in the room.
The Ultimate Acoustics bass trap wedges complete the basic elements of room treatments for improved acoustic performance. It’s important to note that not all of these treatments may be needed. In some rooms, all these treatments may not be enough, either. The physics of audio acoustics are quite complex and these are affected by everything you bring into a room. When it comes to adding acoustic treatment, the phrase “your mileage may vary” is particularly apt.
The average home studio has restrictions beyond the room itself, and in many cases it’s the biggest restriction — budget. When money dictates how much you can attack room deficiencies, a plan with four phases makes sense from both cost and effectiveness points-of-view. While you may choose products other than those reviewed at Hear the Music, the approach takes the same order:
- Monitor Isolation: about $50 and up
- Microphone shield: about $100 and up
- Wall absorbers: about $250 and up
- Bass traps: about $100 and up
As you can see, all four phases will cost about a minimum of $500. An electronic music artist who records only virtual instruments and synths could save money on the microphone shield. Some rooms won’t require bass traps if the monitor sweet spot isn’t affected by standing waves and room modes.
However, if you regularly record using mics or if there are often several people in the studio in various locations, the better the sound throughout the room, the happier you’re likely to be with your studio.
This brings us back to phase 4 — the bass traps. The Ultimate Acoustics traps are one of the most affordable treatments of this type — for a kit. The kit has two wedges, each 24 inches tall. Other manufacturers provide kits with 8 wedges of similar size for around $350, so there’s a slight savings in price per wedge, but there’s the question of whether 8 wedges are necessary. Two or four may be all a particular room needs.
We have to look at the magic of corners to understand what bass traps accomplish. A single point sound source floating in the middle of the sky radiates energy equally in all directions. No, really it does, trust me on this, the example will work so much better if you do. If we move that source to a flat surface on the ground, the energy that used to radiate down is now reflected back up and it reinforces the energy that’s already going up. If we add a perpendicular surface, forming a corner, the same thing happens off that surface. You can see we’re starting to focus the sound energy in a particular direction.
If you’ve ever placed a speaker into a corner and noticed the improvement in bass frequency response, then you’re familiar with this effect. When we are talking bookshelf speakers in a living room, this can be handy to make the stereo sound better. However, when we’re talking about a nearfield monitoring triangle — where we want to hear a recorded signal, unaffected by the room — it’s not so handy.
When that low frequency energy, reinforced by reflecting off the corner boundaries, mixes with the sounds already in the room, we get that great sonic mush mentioned earlier. From this point, we will look at the Ultimate Acoustics bass traps and how these affect the mush. The same principles apply to any foam-style wedge bass trap.
The Ultimate Acoustics bass traps work by essentially adding friction. To take you back to high school physics as briefly as possible, we have to remember that energy can’t be destroyed. It can only be converted. Sound energy bounces around indefinitely until it’s converted to another kind of energy.
Now, home recordists who aren’t as clever as we are will read that and think that all sound ever made should bounce around a room forever, since there’s nothing there to convert it to another type of energy. We, on the other hand, know that sound travels as waves through the molecules of the air in the room. Those molecules, even though we can’t see them, cause enough friction to slow the sound energy and convert it to heat. The effect is miniscule in terms of heat formation, so no need to crank the air conditioner every time you make a noise. Walls also flex in a very minute conversion of sound energy to mechanical energy. All of these little conversions eventually abate the original sound.
The foam used in the UA traps add to the friction. The bass waves that go into the corner and bounce out reinforced now encounter all the little air pockets and foam constructs and therefore have to work harder to get to the reflective surfaces in the corner. Then, after bouncing off the corner boundaries, they have to work through that foam again to reemerge into the room.
That’s how a foam bass trap works in general. The UA traps come in two types. Tested here is the basic Bevel Design model. The Bevel Design with Vinyl adds a perforated vinyl barrier within the wedge that adds further resistance and improves the reduction of even lower frequencies. The lower in frequency a sound wave is, the longer it is in wavelength. The longer the wavelength, the harder it is to convert to heat or mechanical energy.
With a single pair of 24-inch UA wedges, deciding on the most effective location is important, assuming that budget limits you to one kit. If your monitors are fairly close to corners, those corners are probably the best place to start. Measure the approximate distance between floor and ears at the mixing location. Ideally, your monitors will be on about the same plane as your ears. Measure up the wall to this distance, and that’s the target for the center of the UA bass trap. It will extend up and down from that point by a foot.
If your monitors are higher or lower than ear level, adjust the UA traps higher or lower only if the monitors are tilted toward your ears. Otherwise, leave the traps at ear level. If your monitors are not within a few feet of a corner boundary, try the rear room corners for the traps, again using ear height as the center.
To aid test placement, the UA kit comes with adhesive tape. This tape is not strong enough to permanently install the traps. You’ll need a recommended adhesive for that. The tape will, however, permit you to move the traps to find the best location.
That’s all there is to using the UA bass trap wedges. It is possible that your room will benefit from more traps. In fact, floor to ceiling installations do occur. Before going to that length, consider what else is in your room. For example, if you have an upholstered sofa in your studio — it’s very important to have a place for fans to sit while admiring your genius — you have a great big bass trap already there. There may not be a need to go floor to ceiling with additional traps. Single wedges along the back wall with the sofa centered provide substantial protection against modes and standing waves. Consider hanging the wedges higher in this case, perhaps with the bottom of the wedge about ear height. Remember, your room will likely vary exactly how you use any acoustic treatment.
The word “soundproofing” comes up frequently when we discuss acoustics. It is about excluding external noise. We are not talking about that here, so anyone wondering how a single wedge can soundproof things can stop wondering. It doesn’t. What the UA traps are doing is removing the competition. All the sound waves bouncing around the room compete with your monitors. All you want to hear, though, is your monitors. Other waves cause echoes, reverb, phasing and filtering. These are great when you’re applying them in your DAW, but not so great floating in your room.
The UA traps help reduce the amount of reflected sound, which reduces the chances of all these direct/reflected sound interactions. It’s as though you’re turning the volume down on room sound to more clearly hear the monitors. Since room reflections are passive, they go up when you turn your monitors up. Reducing reflected energy is the only way you can alter the equation.
The Ultimate Acoustics bass traps are simply open-cell foam. The foam meets a Class B rating for fire resistance, important to know when building improvements must meet local building codes. The beveled edges provide a finished look that inexpensive foam wedges don’t match. These are often plain, triangular wedges and the thin edges frequently suffer from exposure. Compared to the UA wedges, these seem inferior visually. I suspect the beveled edge of the UA traps improves performance a bit too, though it’s probably only a minor effect. You won’t be embarrassed with UA traps on your walls. They look dedicated and professional.
The Ultimate Acoustics Acoustic Bass Trap Bevel Design kit provides a good starting point for the home studio requiring bass trap treatment. If your room has corners, it probably means you require bass trap treatment, whether by foam wedge or sofa. By all means, try the sofa first! In a 10-by-10 extra bedroom, it may be too much. If so, the UA traps may be the ticket.