Let’s talk about Stonehenge Acoustics and ASC’s QuickSoundField. The Neolithic monument in southern England known as Stonehenge has a 4500 year history that is shrouded in awe, wonderment, and speculation. One of the most recent suppositions is that the site was designed and built largely with acoustical concerns, bearing an uncanny resemblance to a much more modern acoustical tool. At Stonehenge, very large stones were arranged in a complicated series of circles, with meticulously sized and shaped faces oriented in particular directions to provide a seemingly magical sonic quality for those inside the ancient stone ring. Today, we use much smaller versions of these “stones” to create a similarly magical sonic environment inside what is known as the “QuickSoundField,” or QSF.
Everything Old is New Again
Nearly five millennia after this amazing manipulation of sound waves was discovered by simple agrarian tribes, the QSF was developed independently by a number of professional recording engineers in the mid to late 1980’s. It seems the world was waiting for the right tools to emerge. Newly invented by ASC founder Art Noxon, PE Acoustical Engineering, StudioTraps were arranged in a circle around the musical sound source and microphone, with the treble reflective sides facing inward. This created an ideal recording space through two main mechanisms: the many early diffuse reflections combining with the direct sound, and the outward facing absorptive sides of the StudioTraps helping to prevent the unwanted room reflections from getting back into the circle of sound.
Below is a rendering showing the “acoustic shadow casting” provided by the StudioTraps, using a light source to simulate the sound emanating from the mouth of the vocal talent. Similar to the experience of the drummers and singers who used Stonehenge, some of the sound (the good part) comes back, while the rest of the sound (the bad part) goes away. Perhaps those early musician farmers imagined they were repelling evil spirits, while embracing those that helped their crops thrive. These days, sound engineers know well that excessive, flabby bass and midrange ruins their recordings while a tight, bright & rich sound helps their record sales thrive ;)
How it Works
Using light as an analogy helps visualize what is really going on in the QSF. “Beams” of sound radiate through the spaces between the StudioTraps, escaping from the magical circle into a larger space. Then these escaped sounds bounce around the room, eventually heading back toward the source. But now the StudioTraps are on the defensive, with their full-range absorptive qualities presenting a veritable castle wall against the invading hordes of muddy sound. Meanwhile, the inner faces of the StudioTraps, with their curved treble range reflectors, backscatter the clean part of the sound toward the microphone, where it is collected along with the direct sound from the talent to form a homogenous assembly of righteous purity. Vestal virgins and celibate monks alike would be honored to bathe in such sonic excellence, full of life, optimism, vigor, and clarity.
Although the ancients may not have used the modern term “sound fusion recording,” they too understood the importance of proper sound reflections. Some may say we need sophisticated test equipment, CAD modeling, and advanced materials science to create an optimal sound field for recording purposes; others may suggest we look to the wisdom of the past. Based on the achievement of these farmers from a bygone era, the truth probably lies somewhere in the middle.