Development of a Hi-fi Room pt. 3

This week we conclude our 3-part series on Listening Room Development. To establish a reference baseline for the following discussion of Hi-fi listening, it is helpful to skim an article by John Atkinson, published in Stereophile: The View into the Soundstage.

The following was written by ASC founder & president Art Noxon, PE Acoustical ~Enjoy!

There are 3 levels in the evolution of upgrading the audiophile listening room. These upgrades are developed by judicious placing of TubeTraps along the walls and corners of the room. The TubeTrap is an acoustic product specifically developed for the voicing voice or musical instrument recording and playback rooms.


The first level of “dialing in a room” improves the musicality of the playback system. By reducing the coupling between the speakers and the natural acoustics of the listening room, the musicality of the sound system is greatly improved.

overhead view illustration of Stage 1 2C3D Hifi Room with ASC acoustics

Stage 1

In level one the TubeTraps are placed in the 4 corners of the room. Bass collects in the corners of the room and adding bass traps to the corners help control the buildup of unwanted bass reverberation, tightens the bass line providing it with more musical dynamics. Room modes are rooted in the corners of the room and are effectively controlled with corner bass traps.

photo of Stage 1 2C3D Hifi Room with ASC acoustics grey tubetraps

Stage 2


The second level of listening room development unveils a sound stage in the front third of the room, in and around the speakers. Curiously, the loudspeakers seem to sonically disappear, replaced by the sound stage. The speakers become silent sentinels that somehow are secretly weaving wonderous fabrics of sonic imagery throughout the front of the room.

overhead view Illustration of Stage 2 2C3D Hifi Room with ASC acoustics tubetraps

Stage 2

The sound stage has width, depth and height punctuated with a distribution of distinct separate sound sources, typically musical instruments, positioned at various locations across the front of the room. The sound stage is an illuminated and active participant in the music. It appears to actually be the source from which the music is emanating. But the remaining two thirds of the room, where the listener is located remains quiet and unassuming, it’s just the back of the listening room.

Stage 2 2C3D Hifi Room with ASC acoustics tubetraps

Stage 2

At level two, TubeTraps added across the front wall and along the two front side walls. The diffusing panels along the front wall are set facing into the room but along the two front side walls they tend to be facing the front wall, essentially helping to keep the ambience localized in the front of the room.


The third level of listening room development introduces the concept and experience of venue into the audio performance of the listening room. The venue effect is located in the back two thirds of the listening room, the part of the room that surrounds the listener. It immerses the listener into the internal volume of the performance hall, or more specifically the acoustic space in which the performance on the sound stage is taking place. With venue development, the sound stage is no longer viewed from a seat at the back of a non-descript room. Instead, the listener is engulphed in ambience and spatial detailing of the environment in which the sound stage is performing.

overhead view illustration of Stage 3 2C3D Hifi Room with ASC acoustics

Stage 3

This third level of listening room development transforms viewing the soundstage into an unforgettable immersive experience. This level of listening is often referred to as the magic carpet ride, silently powered by the sound machine through the clouds of sound in the sky. A literal sonic time machine, that leaves the listening room behind to set the listener back down in a new, wholly engaging sonic venue, a manifestation of the original venue. As the performance ends, you are gently returned into the familiar silence of your own listening room. A thoroughly transformative experience you know you can never forget, incomparable where all other rooms and systems pale.

Stage 3 2C3D Hifi Room with ASC acoustics

Stage 3

At level three, TubeTraps continue to be distributed along the middle and rear side walls and across the back wall, spaced around the rear two thirds of the room. The music becomes superb, the speakers remain sonically invisible and the sound stage becomes more vivid, stable and detailed. Surprisingly, the listening room completely disappears, replaced by the palpable in-filling that replicates the concert hall, acoustic space or sonic environment in which the original performance takes place. The listener is unknowingly engaged into a truly immersive experience.


This third performance level has been coined 2C3D, short for a 2-Channel 3-Dimension listening room. Different audio manufactures were upgrading their factory reference listening rooms om the early 1990’s and ended up with very similar rooms, which they coined a 2C3D listening room: Avalon Acoustics, Spectral Audio, MIT Cables and ASC TubeTraps. Overture Audio with Terry Menaker in Wilmington, Delaware was the earliest high end audio dealer to setup 2C3D. Overture is running Pass Lab amps and Magico speakers in this setup. Many combinations of gear can produce the same 2C3D effect because the 2C3D effect is derived from the acoustic setup, not the electronics.

6 Moons Hifi Room with tubetraps from ASC

6 Moons Hifi Room

A 2C3D setup for high end audio reviewer’s room, Mike Malinowski of 6 Moons, project by Overture and ASC. This project includes structural isolation and damping of walls and ceiling surfaces as does the Overture demo room. You can read about it here.

2C3D Hifi Room at 6 Moons with asc tubetraps

2C3D Hifi Room at 6 Moons

But before any of these developments took place the pioneering work of J Peter Moncrieff, premier audio equipment reviewer whose International Audio Review IAR publication review of TubeTraps initially took place in 1985 and a follow-up work 1989. Starting with Level 1 he empirically developed Levels 2 and 3, effectively the 2C3D system.

overhead view illustration of a 2c3d hifi room with tubetraps from asc

He called his research and development work Perimeter Control. The first article was in 1985 and only used 9×3 and 11×3 TubeTraps stacked 3 high around the perimeter of the room on about 3’ centers.

IAR: Your Room: The Final Link. Optimizing ASC TubeTraps, Issue 39, 1985; A follow-up article was done in 1989, after replacing many 9×3 and 11×3 with 16×3 TubeTraps. These articles are excellent reading and can be found on the ASC website: IAR: Optimizing ASC TubeTraps, Issue 56. 1989

Room Development

Each level of listening room performance is achieved by adding a complementary set of acoustic devices. Level 2 builds on the existence of Level 1 by adding on the needed compliment to the front third of the room sufficient to achieve level 2. Level 3 builds on level 2 by adding a specific acoustic compliment to the remaining two thirds of the room, which takes it to level 3. There is no lost investment when the upgrade sequence is a progression in the number and arrangement of basic building blocks.

Thanks for reading!

View the entire article.

6 Moons 2C3D Hifi Room with ASC acoustics

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