 |
250
Aural Exciter Type III - Discontinued |
|
| |
| The
Aphex Aural Exciter Type III utilizes a patented audio process
that will recreate and restore missing harmonics. These harmonics
are musically and dynamically related to the original sound.
When added, they restore natural brightness, clarity and presence,
and can actually extend audio bandwidth. These harmonics are
so low in level however, they add little power to the signal.
Unlike an equalizer or other "brightness enhancers"
which can only boost high frequencies, the Aural Exciter Type
III extends the high frequencies. It is a single-ended process
that can be applied at any point in an audio chain, and needs
no decoding. |
|
New Features
|
| • |
Two
Modes of Noise Reduction |
• |
Null
Fill |
| • |
Adjustable
Harmonics Mixing |
• |
Aphex
VCA 1001 |
| •
|
SPR™
Spectral Phase Refractor |
• |
Servo
Balanced I/O on XLR-type connectors
|
| Standard
Features |
|
| •Two
independent low noise channels |
| •
Operates with I/O Levels from +8dBm to 10dBm |
| •
Operates Balanced or Unbalanced Automatically |
| •
International Power Mains Selection |
| •
RF Filtered AC Power Input |
| •
Direct Relay Bypass - and Remote Control of Relay Bypass |
| •
Solo Function |
| •
All Switch Settings LED Indicated |
| •
Stable, Repeatable Settings |
| •
Easy to use
|
| Applications |
| •
|
Recording
Studio Tracking and Mixdowns Adds air, sparkle and
presence to voices and music. Improves imaging. |
| •
|
Sound
Reinforcement Adds clarity high frequency dispersion
and penetration without increasing chance of feedback |
| •
|
Sampling
Extends bandwidth and adds detail |
| •
|
Film & Video Restores clarity and intelligibility
to dialogue tracks, sound effects and music |
| •
|
"ON
AIR" Broadcasting Increases loudness, clarity
and presence without distortion or overmodulating |
| •
|
AM
Broadcasting Provides the clarity and brightness of
FM |
| •
|
FM
Broadcasting Restores naturalness and openness normally
lost due to processing |
|
The Process |
The
Aphex Aural Exciter Type III utilizes a patented audio process
that will recreate and restore missing harmonics. These harmonics
are musically and dynamically related to the original sound.
When added, they restore natural brightness, clarity and presence,
and can actually extend audio bandwidth. These harmonics are
so low in level however, they add little power to the signal.
Unlike an equalizer or other "brightness enhancers"
which can only boost high frequencies, the Aural Exciter Type
III extends the high frequencies. It is a single-ended process
that can be applied at any point in an audio chain, and needs
no decoding.
The Aural Exciter process consists of two audio paths. The main
path and the process sidechain path. The main path transparently
conveys the audio signal directly from the input stage to the
output stage, maintaining unity gain with wide dynamic range.
The sidechain path contains all of the Aural Exciter processing
circuits and receives audio from the input stage.
A mixing circuit in the main path allows the sidechain output
signal to be mixed with the main signal. The user adjusts the
amount of "MIX" to set the strength of the effect. |
|
Modes of Noise Reduction |
| Two
Modes of Noise Reduction are provided with the Aural
Exciter Type III, allowing it to provide enhancement without
adding to the noise floor of reasonably noise free sources.
It can also enhance the brightness, detail and clarity of seriously
noisy audio sources while, at the same time, erasing much of
the original noise. |
• |
Mode
"A" operates as a linear sidechain expander
with variable threshold. The expansion ratio of 2.5-to-1 permits
the sidechain "MIX" to follow the signal level below
threshold, so when the higher frequencies of the input drop
below threshold, the "MIX" will drop at a proportional
2.5 to-1 ratio. Thus the original signal-to-noise is not affected
even with a great deal of enhancement. |
•
|
Mode "B" is a revolutionary new noise
reduction technique which operates to actually "erase"
source audio noise while the Type III Aural Exciter enhances
the signal. This allows you to restore brightness and intelligibility
to noisy recorded tracks or other noisy sources and improve
the signal-to-noise ratio! |
| Both
modes are fast and easy to use, and effective in any application
from live sound to broadcasting and recording. |
| "SPR
" (Spectral Phase Refractor) |
The
"SPR " (Spectral Phase Refractor) function of the
Type III is a totally new concept in psychoacoustic enhancement
which can produce some amazing results. Through the many steps
of recording, duplicating, distributing and reproducing sound,
the phase of the low frequency audio spectrum becomes delayed
compared to mid and high frequencies. This is a natural and
unavoidable effect which becomes worse with each generation.
When
the bass frequencies become delayed in time compared to other
sounds, the bass loses fullness and definition and seems to
become less powerful even though there may be no actual loss
of bass frequency response. The high end also loses definition,
seeming to get duller.
Amplitude
equalization at this point will not fully restore the clarity
and bass power... indeed, it may worsen the condition causing
clipping or overload distortion. The "SPR" corrects
the bass delay anomaly to restore clarity and openness and significantly
increases the apparent bass energy level without adding any
amplitude equalization or "bass boost".The "SPR"
function works harmoniously with the new Aural Exciter circuitry
to give the Aural Exciter Type III amazing new capabilities. |
| Other
Special Adjustments: |
| The
"Drive" control of previous Aural
Exciters has been eliminated and Adjustable Harmonics
Mixing of the exact harmonics level desired is now
available making the Type III more flexible and easier to use.
Null
Fill is a new and useful tuning adjustment introduced
for the first time with the Aural Exciter Type III. The addition
of NULL FILL to the PEAKING and TUNE controls gives the Type
III more power and flexibility to enhance all types of audio
sources. To understand how it works, it is necessary to understand
a physical phenomenon called "Phase Nulling" which
occurs with all Aural Exciters when the MIX control is adjusted
to obtain high frequency enhancement.
There
is a time delay associated with the sidechain signal which
is an important part of the operating theory of the Aural
Exciter. This time delay causes transient waveforms to be
slightly "stretched" as the sidechain signal is
added to the main audio path. The "stretched" transients
are then perceived by the ear as more pronounced or "louder."
The side effect of the time delay is a "dip" or
"null" in the output equalization curve. The null
can be a desirable characteristic because it compensates for
the slight additional power added to the signal by the high
frequency shelving boost. The null de-emphasizes the frequency
range around the TUNE control setting, thus giving even greater
emphasis to the higher frequencies.
There
are times, however, when the Phase Null is unwanted. The NULL
FILL control allows the user to "fill-in" the phase
null to any desired amount, thus further improving presence. |
| Servo-Balanced
Inputs and Outputs |
| Although
more costly than conventional designs, servo-balancing offers
many advantages. Servo-balanced input circuits absorb high common-mode
voltages found in long cable runs without sacrificing headroom.
Servo-balanced outputs are not only short-circuit proof, but
can be used single-ended at any time without the usual 6 dB
loss of conventional circuits. To use input or output single-ended
(unbalanced) the user need only ground the unused pin. Inputs
and outputs are fully RF protected. The unity gain 1/0 structure
is normalized for both + 4dBu (professional) and -10dBV (IHF)
operating levels by switch selection from the rear panel. |
| Some
Typical Applications |
| The
Aural Exciter may be used in many ways for audio enhancement.
Depending upon the requirements, either pre-or post-processing
may be selected. Either source optimization or system optimization
or a combination of both is possible. For example, a PA. system
may be greatly enhanced by using the Aural Exciter to increase
the intelligibility of the loudspeakers, thus improving penetration
of the sound around corners and in areas usually difficult to
fill. In another case, the source may sound dull and hard to
understand. The Aural Exciter will compensate for this deficiency
by adding brightness and clarity to the sound more effectively
than use of equalization alone. The
Aural Exciter may be used to "pre-process" recordings
to anticipate the audio degradation in the medium or during
subsequent reproduction. Much of the detail added by the Aural
Exciter will survive filtering and distortion of the reproduction
equipment, and provide a better quality audio playback. Audio
and Video Cassette duplication are examples of this application.
Broadcasting is another good example.
In
the recording studio, post production suite or similar environment,
post-processing of previously recorded sound tracks can restore
lost vibrance and realism, even to the extent of saving dialog
or sound effects which were thought to be unusable. Instruments
and vocals can be made to stand out in the mix without substantially
increasing the mix levels or using equalization.
Many
electronic instruments are limited by their sampling rate
(bandwidth) and word length (resolution), they can sound lifeless.
The Aural Exciter actually extends bandwidth and adds details
making synths, samplers and drum machines come alive.
Video
and film audio are both bandwidth limited and compressed.
The Type III is especially useful in creating the perception
of higher frequencies and greater dynamics with pre processing,
thus bringing more presence and clarity to the final product. |
| SPECIFICATIONS
- Aphex Model 250 - Aural Exciter Type III |
| Audio |
| Frequency
Response |
+0,
-1 dB 1 Hz to 190 kHz |
| Crosstalk
(10 Hz - 22kHz) |
Better
than 90 dB up to 20 kHz |
| THD |
.01%
max at +27dBm I/O |
| IMD
|
.01%
max at +27dBm I/O |
| Maximum
I/O Level |
15.5
VRMS (+27 dBu ref 600 ohms) |
| Nominal
Gain |
0dB
(unity) with output loaded into 600 ohms |
| Input
Impedance |
19.5k
ohms / 600 ohms (rear panel switch selectable) |
| Load
Impedance |
600
ohms or greater |
| Output
Impedance |
65
ohms |
| Unweighted
Output Noise |
20
Hz - 20 kHz -86dBm (12 microvolts RMS) |
| Unweighted
SNR (for +4 operating level) |
92
dB |
| Dynamic
Range |
114
dB |
| Output
Circuits |
Servo
Balanced Transformerless |
| Input
Circuits |
Servo
Balanced Transformerless |
| Input
CMRR |
Better
than 60 dB 20 Hz to 10 kHz |
| Input
RF Rejection |
Better
than 40 dB at 800 kHz; better than 60 dB above 2 MHz |
| Other
Specifications |
| Power
Requirements |
100
/ 120 / 220 / 240 VAC 50-60 Hz 16W |
| Dimensions
|
19"W
x 1.75"H x 9" D 1 Rack U (482.6mm x 44.5mm x
228.6mm) |
| Net
Weight |
8
lbs (3.63 kg) |
| Shipping
Weight |
11
lbs (5 kg) |
| Aphex
Aural Exciter covered by US Patent Number 4,150,253.
Additional Patents
Pending. Foreign Patents granted and pending. |
| Accessories |
| Model
51 Plexiglass Security Cover |
|
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|
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