User Manual
Table Of Contents
- 1. Hardware
- 2. Technology Overview
- 3. Software
- 3.1 Software Installation
- 3.2 Using the Software
- 3.3 Custom edit processing module
- 3.4 Audio Module Parameters
- 3.4.1 Input Source
- 3.4.2 Expander
- 3.4.3 Compressor & Limiter
- 3.4.4 Automatic Gain Control
- 3.4.5 Equalizers
- 3.4.6 Graphic Equalizer
- 3.4.7 Feedback Suppressor
- 3.4.8 Noise Gate
- 3.4.9 Ducker
- 3.4.10 Ambient Noise Compensation (ANC
- 3.4.11 Auto Mixer
- 3.4.12 Acoustic Echo Cancelation
- 3.4.13 Noise Suppression
- 3.4.14 Matrix
- 3.4.15 High and Low Pass Filter
- 3.4.16 Delay
- 3.3.17 Output
- 3.4.18 USB interface
- 3.5 Settings Menu
- 4. Control
- 5. FAQs
- Appendix A: Module ID Distribution
- Appendix B: Module Parameter Types (1)
ALF-DSP 88-U
-16-
Sine Wave: Select the Sine Wave button and drag the frequency to generate sine wave with selected freque ncy
(selectable 20Hz - 20 kHz). You may regulate the output level (unit: dBFS) based on your requirements. Use the level
fader to adjust or click the text field to designate a value.
White Noise: When obse rved on the frequency spectrograph with constant bandwidth, and set to a flat frequency
spectrum, white noise signal has equal energy across all frequencies.
Pink Noise: The frequency intensity level of pink noise is mainly distributed in the middle and low frequency bands.
It decreases with a speed of 3dB/Oct in the middle and low frequency bands.
In addition, you may also find the following menu by right clicking each fader on the main menu.
Group Setting: Open the group setting interface window.
Minimum and Maximum Gains: Limit the maximum and minimum values of a channel. After it is commissioned, if
you do not wish that the system's stability is affected due to external factors, you may set up a maximum gain.
3.4.2 Expander
Although similar in concept, the expander has a different operating principle from the compressor. It can expand
the dynamic range of a signal. The most fundamental difference in these two devices lies in that, the compressor
works on the signal higher than the threshold, while the expander works on the signal lower than the threshold.
Louder and softer signals become relatively louder and softe r respectively. It can be seen from Fig.3.2 that, when
the expansion ratio reaches 1:2, the input signal 20dB lower than the threshold will generate an output signal 40dB
lower than the threshold. Thus, as shown below, the signal lower than the threshold will extend downwards and
cause sof ter level. When an expansion ratio 1:20 is adopted. The expander seems to be a noise gate in terms of the
transmission features. In fact, a noise gate is an expander with a great expansion ratio.
Fig.3.2 Expander
The expander has the following control parameters:
Threshold: The expander activates only when the signal exceeds this threshold (allowing the transmission of the
signal). As a standard practice, the signal is often set at the ambient noise level
Ratio: Ratio refers to the slope below the threshold point on the gain curve. When the slope is set at a high level,
gating will activate.