VoxGuard Nearfield Absorber
- Controls ambient space around the microphone
- Creates intimate sound field around the mic
- Delivers cleaner more articulated voice track
- Allows you to add ambiance or effects as needed
The Primacoustic VoxGuard is a high performance ambient
noise attenuator designed to surround the microphone and reduce
unwanted sounds from contaminating the recording. This nearfield
absorber works by creating an acoustic boundary around the microphone
that at once contains the voice while eliminating room reflections from
entering the mic.
Unlike other similar offerings that employ complex steel
parts that are both heavy and cumbersome, the VoxGuard is light weight
and extremely easy to use. It starts with a high-impact ABS outer
surround shell that snugs onto the mic stand using the microphone's
clip to hold it in place. The light weight design makes positioning the
VoxGuard easy without the usual fear of the stand falling over which
could ultimately damage the microphone.
This makes the VoxGuard effective when used with round
base stands, tripods and even with large studio booms. Once mounted, an
innovative rear access cable port allows the microphone to be
articulated and directed at a specific source, thus enabling the
VoxGuard to also be used as an acoustic screen.
The acoustic magic is performed with a high-density open
cell acoustic foam liner. This effectively absorbs the voice range
while keeping room ambiance out to produce a dry rendering. This is
particularly important when attempting to recording in rooms with less
than ideal acoustics or in noisy spaces. Since the VoxGuard is 50%
larger than comparable products, noise flanking is significantly
reduced and performance vastly improved.
The VoxGuard is ideal for recording studio vocals,
voice-over tracks for film and TV post production, pod casting and
The Science Behind The VoxGuard
- Sound Of The Room
- Eliminating The Sound Of The Space
- The VoxGuard Design
The VoxGuard is a simple device that employs well known
acoustic principles to minimize room ambiance from entering the
microphone. This allows a greater percentage of the source to be
captured without the echo, reverb and resonance from the room. Once the
'dry recording' is on tape, artificial ambiance in the form of digital
reverb, echo and EQ is then added.
The science behind the VoxGuard is simple. It combines
absorption by way of high density open-cell foam with an acoustic
shield to prevent ambient sound from entering the mic. This page
explains the science behind the design.
Eliminating The Sound Of The Space
Put up a microphone in a room and hit 'record'. The sound
of the voice will compete with the sound echoing off the walls. These
are known as primary reflections, flutter echo and standing waves.
These will invariably arrive at the microphone after the original sound
and depending on how loud they are, will cause varying degrees of phase
cancellation known as comb-filtering.
Although in some cases one may want to record using the
natural room's effect, today it is common practice to record a dry
vocal track and only add artificial ambiance during the mixing phase.
Most engineers prefer to work this way as committing to room ambiance
early-on usually conflicts with the instruments and limits options.
The VoxGuard Design
With acoustics, one can either absorb sound or reflect it. The
VoxGuard performs both functions at the same time. First, when singing
into the microphone, sound is captured by the mic while a good
percentage of sound breezes by. In space, this 'extra' sound would go
forever without echo as there are no boundaries. In an anechoic test
chamber, sound is completely absorbed as there are no hard reflective
surfaces. In this case, the VoxGuard's high density open-cell acoustic
panel absorbs much of the energy in the critical voice range.
An open microphone picks up a mix of direct sound (blue arrows) and reflected sound (red arrows).
The VoxGuard baffel blocks reflected sound from entering the mic and
the absorber layer minimizes reflections within the baffel allowing the
dry vocal to be recorded.
What spills over is then spread into the room. This echoes around in
the form powerful primary reflections and flutter echo that create the
room's reverberant field. The VoxGuard's curved outer shield is
designed to reflect unwanted energy away while the larger size -
upwards to twice as big as others - reduces flanking. This effectively
creates a boundary that stops sound from coming back into the mic,
reducing the ambient effect.
The results is predictable: With more of the original source and
less of the reverberant field, the recording engineer is better able to
control the sound of the voice or instrument to best fit the recording.