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Paragraphic Equalizer
This unique equalizer combines the flexibility of a parametric equalizer with the ease of use associated with a 10 band graphic equalizer. The actual frequency response of the filter is graphically controlled and/or displayed. Virtually any frequency domain transfer function that you can dream of can be created with this filter. Many presets are provided to facilitate many unusual equalization situations.
The Paragraphic Equalizer
The Paragraphic Equalizer is a unique form of a parametric equalizer employing IIR techniques. It combines the graphical representation of its transfer function (frequency response curve) with the versatility of a parametric equalizer. Additionally, it provides you with up to 10 bands of equalization. It differs from the graphic equalizer in that three parameters are adjustable for each band:
The following additional controls and displays are provided:
The Parametric Equalizer displays its frequency domain transfer characteristic graphically. Therefore, it is referred to as the DCArt10 / DCForensics10 "Paragraphic" equalizer. It can be modified using your mouse by dragging the inflection point dots, and modifying the bandwidth using the octave control. You simply draw the shape of the response, which you desire, and the algorithm adjusts the parameters to match the response curve. Each band is represented by a single square "dot" on the graph. The "active" dot (the one being adjusted) will be the larger one displayed. That is the dot for which the parameters are being displayed numerically on the control panel. You can use the mouse to drag any of the dots, which actually represents a frequency inflection point, wherever you wish. If you want to sharpen or widen the response of any inflection point, use the “Octaves” control to achieve the desired curve for a highlighted band dot. It is often very useful to use the spectrum analyzer, found under the View menu, in conjunction with the Paragraphic Equalizer. You will then be able to see the exact effect that you are imposing on the .wav file signal.
Under the factory presets listing, you will find a number of useful audio restoration functions, including the RIAA curves. Also, various inverse RIAA curves with a variety of turnover frequencies are available. These features enable you to use a standard RIAA pre-amplifier to transfer acoustical and electrically recorded 78 RPM records to your hard drive, and re-compensate at another point in time, without having to purchase specialized hardware. Also, of interest is the family of Fletcher-Munson Equal Loudness Contours at different sound pressure levels. These can be used to compensate for the response of the human ear depending on the loudness level that you expect a particular audio piece to be auditioned.
Shelving Filters: The top band (right-hand side of the graph) always operates as a shelving function (a pole-zero pair). The rest of the bands are second order resonant filter systems (often referred to as peaking filters), except the bottom band (left-hand side of the graph) which can be set either as a shelving transfer function or as a peaking routine. It defaults to a peaking filter, but can be converted to a shelving function by checking the shelving checkbox (“Low Freq Shelf”). So, you can create a system in which you have a low frequency and high frequency shelf with 8 peaking filter bands in-between if you so choose. If you only want to work with two shelving filters, just check the “Low Freq Shelf” checkbox and then reduce the number of filters to 2. One of those two will be the upper frequency shelf and the other one will be the lower frequency shelf. You can then adjust both to achieve the desired upper and lower frequency shelving response. The Amplitude and Frequency controls apply to the shelving function(s), but not the Octaves control. “Octaves” only apply to the various filter bands when they are operating in non-shelving mode(s).
Note 1:
As with all of the DCArt10/DC Forensics10 filters, sample theorem dictates useful bandwidth for the algorithms. The Paragraphic Equalizer will only have a useful bandwidth up to about 10 kHz with a 22.05 kHz sample rate, and about 5 kHz at 11.025 kHz. It will be fully useful with sample rates of 44.1 kHz and above.
Note 2:
Many of the Paragraphic Equalizer presets such as the RIAA, Reverse RIAA and NAB curves are defined over the entire audio spectrum consisting of at least 20 Hz to 20 kHz band spread values. Therefore, the use of any sampling rates less than 40 kHz will invalidate the accuracy of these curves. We recommend using only 44.1 kHz or higher in order to properly realize these equalization curves.
Note 3:
Random white noise can be converted to pink noise by feeding it through the appropriate factory preset(s) within the Paragraphic Equalizer.
Virtual Phono Preamplifier (VPP)
This unique equalizer combines the flexibility of a parametric equalizer with the ease of use associated with a 10 band graphic equalizer. The actual frequency response of the filter is graphically controlled and/or displayed. Virtually any frequency domain transfer function that you can dream of can be created with this filter. Many presets are provided to facilitate many unusual equalization situations.
The Paragraphic Equalizer
The Paragraphic Equalizer is a unique form of a parametric equalizer employing IIR techniques. It combines the graphical representation of its transfer function (frequency response curve) with the versatility of a parametric equalizer. Additionally, it provides you with up to 10 bands of equalization. It differs from the graphic equalizer in that three parameters are adjustable for each band:
- Frequency: (Hertz - 10 to 20 kHz)
- Amplitude: (Attenuation or Amplification of up to +/- 20 dB)
- Octaves: (Q or bandwidth - 0.05 to 3.0)
The following additional controls and displays are provided:
- Number of filters: (1 to 10)
- Output Gain: (+ / - 20 dB)
- Reset Levels: (Resets the Paragraphic EQ to zero dB and factory default frequencies)
- Overload indicator: (Illuminates when full-scale output {clipping} occurs.)
The Parametric Equalizer displays its frequency domain transfer characteristic graphically. Therefore, it is referred to as the DCArt10 / DCForensics10 "Paragraphic" equalizer. It can be modified using your mouse by dragging the inflection point dots, and modifying the bandwidth using the octave control. You simply draw the shape of the response, which you desire, and the algorithm adjusts the parameters to match the response curve. Each band is represented by a single square "dot" on the graph. The "active" dot (the one being adjusted) will be the larger one displayed. That is the dot for which the parameters are being displayed numerically on the control panel. You can use the mouse to drag any of the dots, which actually represents a frequency inflection point, wherever you wish. If you want to sharpen or widen the response of any inflection point, use the “Octaves” control to achieve the desired curve for a highlighted band dot. It is often very useful to use the spectrum analyzer, found under the View menu, in conjunction with the Paragraphic Equalizer. You will then be able to see the exact effect that you are imposing on the .wav file signal.
Under the factory presets listing, you will find a number of useful audio restoration functions, including the RIAA curves. Also, various inverse RIAA curves with a variety of turnover frequencies are available. These features enable you to use a standard RIAA pre-amplifier to transfer acoustical and electrically recorded 78 RPM records to your hard drive, and re-compensate at another point in time, without having to purchase specialized hardware. Also, of interest is the family of Fletcher-Munson Equal Loudness Contours at different sound pressure levels. These can be used to compensate for the response of the human ear depending on the loudness level that you expect a particular audio piece to be auditioned.
Shelving Filters: The top band (right-hand side of the graph) always operates as a shelving function (a pole-zero pair). The rest of the bands are second order resonant filter systems (often referred to as peaking filters), except the bottom band (left-hand side of the graph) which can be set either as a shelving transfer function or as a peaking routine. It defaults to a peaking filter, but can be converted to a shelving function by checking the shelving checkbox (“Low Freq Shelf”). So, you can create a system in which you have a low frequency and high frequency shelf with 8 peaking filter bands in-between if you so choose. If you only want to work with two shelving filters, just check the “Low Freq Shelf” checkbox and then reduce the number of filters to 2. One of those two will be the upper frequency shelf and the other one will be the lower frequency shelf. You can then adjust both to achieve the desired upper and lower frequency shelving response. The Amplitude and Frequency controls apply to the shelving function(s), but not the Octaves control. “Octaves” only apply to the various filter bands when they are operating in non-shelving mode(s).
Note 1:
As with all of the DCArt10/DC Forensics10 filters, sample theorem dictates useful bandwidth for the algorithms. The Paragraphic Equalizer will only have a useful bandwidth up to about 10 kHz with a 22.05 kHz sample rate, and about 5 kHz at 11.025 kHz. It will be fully useful with sample rates of 44.1 kHz and above.
Note 2:
Many of the Paragraphic Equalizer presets such as the RIAA, Reverse RIAA and NAB curves are defined over the entire audio spectrum consisting of at least 20 Hz to 20 kHz band spread values. Therefore, the use of any sampling rates less than 40 kHz will invalidate the accuracy of these curves. We recommend using only 44.1 kHz or higher in order to properly realize these equalization curves.
Note 3:
Random white noise can be converted to pink noise by feeding it through the appropriate factory preset(s) within the Paragraphic Equalizer.
Virtual Phono Preamplifier (VPP)