The
tri-corner of a room acts to transform and compress all of
the acoustic energy in a sound wave into pure pressure fluctuations.
TubeTraps are designed to take full advantage of the acoustic
pressure zones created in the corners of a room. They convert
the pressure changes into air movement within the dense walls
of the TubeTrap. Through regulated friction in the walls of
the TubeTrap, energy is damped out of the wave.
Because of how it works, the TubeTrap is
known as a "pressure zone bass trap." The diameter
of the TubeTrap, not the length determines the low frequency
cutoff. Only TubeTraps have built-in diffusive reflection
panels to maintain ambience control. TubeTraps work best in
areas where there is heavy bass, such as the corners of the
room.
Room
Modes
When
low frequency sound is injected into a room, the waves reflect
back and forth. At certain frequencies, the reflection patterns
begin to overlap and lock into a synchronized condition with
each other to produce standing waves. Whenever this pattern
overlaps the speakers we get "room boom", an overpowering
emphasis by the room/speaker arrangement to play only a few,
very strong bass notes.
Nothing can actually get rid of room modes,
short of removing the room entirely. But adding bass traps
will even out the bass response and improve transient attacks
and decay. Although every mode has a unique pattern of pressure
zones distributed throughout the room, all modes have pressure
zones in the tri-corners. ASC is the pioneer of corner loaded
bass traps, and the TubeTrap remains the unsurpassed upgrade
for all high performance audio acoustic systems.
Boundary
Reflections
When
a woofer is located near a wall, its freefield frequency response
becomes distorted. The nearby reflection drives a pressure
wave back over the speaker cone. Walls, floor and corner reflections
produce 5 to 20ms delay signals that mix with the direct signal
at the driver to induce comb filtering effects into the bass
range of the speaker and as well, side lobe beaming patterns.
A TubeTrap located at each of these reflection
points will reduce the strength of the reflection. This reduces
the comb filtering and side-lobing effects in the bass range.
But not all wall reflections are bad. Speakers located near
walls deliver better deep bass. Our boundary conditioning
Traps are bandwidth limited to allow them to defeat comb filtering
and beaming effects but not at the expense of wall loading
in the deep bass range. Diffusive strips in the Traps are
oriented behind the speakers to better develop the ambience.
Bass
Loading
TubeTraps can also
be used in the open, close coupled to speakers in order to
improve their performance. By stacking TubeTraps to expand
the effective size of the speaker baffle board, the effect
of increased bass directivity and efficiency is achieved.
This works with sealed, front ported or dipole speakers, flown
or stage mains, hi-fi, studio monitors, portable PA and nightclub
systems.
In addition, the TubeTraps can be stacked
in a forward stepped array that casts an acoustic shadow to
the side of the speakers. The diffusive strips of the TubeTraps
are oriented away from the front of the speaker for color-free
horn loading. This shadowing technique protects on-stage mics
from feedback, small room listening from side wall reflections
and halls from excessive reverberation.