FAQ's

Why do I need acoustics?

Whether you make a living recording and mixing sound or have a serious passion for listening to music reproduced in the finest manner, acoustic treatment will enhance your experience. The entire signal chain, from the musician's mouth or instrument to the aficionado's golden ear, needs proper attention or the whole effort can be for naught.

The pages in this section explain some of the fundamental behavior of sound in rooms. The bottom line is: if you care about the accuracy of your work or listening experience, you need your room to add minimal coloration to the sound between your speakers and your ears. Acoustic treatment is the tool to achieve this.

Room Resonance

Sound Absorption

(more to come)

Seriously, why do I need acoustics?

Here's a little math, bear with us. Your ear holes might have a combines area of one square inch. A speaker is often set up about 6 feet away from you, and the sound expands after launch.  Across much of the audio spectrum it expands in an almost hemispherical pattern, with the size of the wavefront reaching about 32000 square inches. The percentage of this sound reaching your ear directly is 0.003%. Not much!

OK, let's try that out in a nearfield setup, this time with the speakers 3 feet away. The expanded wavefront is a "mere" 8000 square inches, and now you receive 0.01% of the sound directly. While triple that of the previous example, this is still vanishingly low.

Where does the other 99% go? It bounces around the room, interacting with surfaces and objects, being stored in some places, absorbed in others, much of it chaotic and asymmetric in nature. Then much of it reaches your ears, throwing off timing cues and harmonic structure, adding or subtracting within your perception, depending on phase alignment at various frequencies, 

The bottom line is that you MUST pay attention to this lion's share of the sound output of your speakers if you are to have a hope of experiencing fidelity and musical accuracy.

Does my room need to be full of TubeTraps?

Excellent question - and the answer is No. While many of the best-sounding rooms you see will indeed seem to be veritable forests of TubeTraps, you can achieve an excellent sound quality in your space with as few as (4) well-placed TubeTraps. We find a 4-pack to be a good starting point for both studios and HiFi rooms, albeit using different products. 

For studio acoustic control, we recommend the StudioTrap for maximum versatility and flexibility. Increase your kit from there, adding lower bass trapping and spot reflection control as needed.

For HiFi acoustic treatment, we recommend the Model-13 TubeTrap for both mud-zone control and ample treble diffusion in a relatively small package. Add larger units and more stacks as budget permits, until your room sound is perfect.

Shouldn't I focus on the early side wall reflections?

This is a common starting point for room acoustics, and we admit that it is a very audible improvement, one that even beginner audiophiles can perceive. Listening refinement takes some practice and concentration, and often the burgeoning audiophile does not know how scintillating the sound from a true high-end system can be - until it is heard.

This is a question of immediate satisfaction versus long-term. We feel that placement of TubeTraps in the corners behind the speakers provides more overall benefit in 90% of rooms than sidewall reflection control. However, some unique rooms lack front corner buildup, and that is an occasion for installing SoundPlanks at the mirror points on your side walls. Just be sure to cover both the near reflections and the cross-talk reflections.

What about soundproofing?

Many people interchange or confuse the terms "soundproofing" and "acoustic treatment". It is important to realize that they are not the same, and often require different tools to achieve. While true that a properly "soundproofed" room also requires adequate sound absorption, different mechanisms control the transmission of sound than do the elimination of sound energy (or rather, conversion to heat).

In most basic terms, soundproofing requires an air-tight barrier around the noise source that is also massive and inflexible. A great example would be a bank vault with 12" poured concrete walls and a hermetically sealed door. Virtually no sound could escape...but it would also take a really long time to die down after the sound source stops playing. This is essentially a reverberation chamber.

On the other hand, acoustic treatment generally refers to a reduction in reverberation in certain audio bands, which is accomplished through a combination of sound absorption and diffusion. Common absorbers are porous materials that offer copious amounts of friction to vibrating air molecules, slowing their movement and thus reducing the energy of the propagating sound wave. Diffusers are commonly curved or faceted surfaces that convert an incident sound wave into many weaker sound waves, spreading them around the room more widely than a flat, specular reflection.

If you are concerned about soundproofing, but also want the room to sound good on the inside, the ASC IsoWall System is the answer. This unique construction system was developed over decades of designing and building professional recording studios, and since then has also been implemented in hundreds of dedicated HiFi rooms and home theaters. It is the only isolation system that we know of that is specifically engineered for audio.

The ASC IsoWall outperforms all standard forms of soundproof construction by adding the necessary elements to overcome those systems' weaknesses. Because of the added mass and decoupling within the wall construction, the room's interior becomes peaceful and quiet--free from disturbing exterior noises. For the same reason, loud noises created within the space by powerful sound systems is contained so neighbors and other inhabitants of the home are also not disturbed. The crux is the integrated damping that eliminates the dreaded coincident dip, a tonal range in which the isolation is reduced significantly, and both parties, inside and out, may feel the system is broken. With the IsoWall, the isolation remains steady throughout the entire operating bandwidth, and everyone stays happy.

Beyond its sound isolating characteristics, an ASC-built wall has the added ability to condition the room's acoustic signature in the low-end bass frequency spectrum. By utilizing our proprietary WallDamp material (a visco-elastic polymer) throughout the system, low frequency energy is absorbed into the wall. This reduces bass feedback and shuddering walls, which results in a clean, rich sound and well-balanced frequency response.

The ASC IsoDeck is a great way to isolate your floor and prevent unwanted room coloration due to resonance and rattle. Unlike rubber "boots" that can transmit sound, IsoDeck uses wool felt for a truly floating floor. Great for drum kit platforms or the entire studio floor.

ASC's Cable Pass Through product makes it easy to run cables up to 3/4" thick through walls, while maintaining a tight soundproof seal.

Recording Techniques

The Quick Sound Field is an incredibly versatile, adjustable and portable recording environment. The QSF allows the engineer to create an acoustically perfect sub-space within any recording environment. A virtual studio within a studio. Quick Sound Field is a recording technique that uses 8 or more StudioTraps.

ASC's Quick Sound Field has revolutionized the recording industry by enabling the engineer to simply bypass the problems due to poor room acoustics and easily set up a controlled acoustic subspace system that delivers depth and clarity to your tracks, time and time again.

In a normal room, the sound is reflected off wall, ceiling and floor surfaces to produce a room signature signal that leaks back into the mic. Typical wall treatments, including acoustic foams and fiberglass panels, will dramatically reduce sound reflections, but the end result is that typical dead studio sound with no presence or ambiance that is followed by some sort of loud level room honk. Our QSF system can offer you a controlled acoustic environment, and save you time, hassles and money. No more wishing you could fix it at the mix!

The Quick Sound Field is created out of an array of ASC's patented StudioTraps, the most versatile acoustic tool for today's modern recording studio. The front half of the StudioTrap is treble range reflective and the back side is treble range absorptive. The entire surface of the Trap is bass range absorptive. This remarkable blend of acoustic properties provides a means to the balanced, broadband control of sound.

StudioTraps are adjustable in height and are usually set up midway between the floor and ceiling, but they can be raised or lowered for different mic positions or line of sight requirements. By setting up the StudioTraps around the talent, iso-booth techniques can be developed to more easily control the sound. In the treble range, the QSF eliminates undesirable room reflections while creating a time-delayed diffusive backfill, injecting a sense of acoustic presence into the track.

The QSF satisfies all the requirements necessary for a professional iso-booth. Engineers and talent love the level of detail they can get with the QSF. They get the sound that couldn't be heard before, even in some of the world's most advanced studios.

What is the ATTACK Wall?

The AttackWall is the mixing complement to the Quick Sound Field. Enclosing your monitors, console and mix position with an AttackWall converts any space into a world class control room. Legendary engineer Bruce Swedien says, "No matter where I go, I take these wonderful devices with me." Studios may come and go, and the AttackWall goes where ever you go.

Where should I place my monitors?

The speakers will need to be positioned so that they sit symmetrically between the walls of the room, otherwise the stereo image will be distorted. Putting speakers too close to corners tends to emphasize the bass in an unpredictable way, so try to place your speakers away from the room boundaries and make sure the setup is symmetrical, with the tweeters pointing at your head in your normal monitoring position.

Relatively small changes in speaker position can affect the sound quite significantly, so experiment with moving your speakers forward or backwards while some known commercial material is playing and aim for a smooth response, especially at the low end. If some bass notes seem louder than others, move the speakers around until the problem is minimized. Mounting the speakers on solid stands makes quite a difference..