User manual BSS DPR402

[. . . ] DPR 402 User Manual 1 V3. 0 JMK 13 May 1997 This equipment has been tested and found to comply with the following European Standards for Electromagnetic Compatibility: Emission Specification: Immunity Specification: Mains Disturbance: EN55013 EN50082/1 EN61000/3/2 (1990) (1992) (1995) (Associated equipment) (RF Immunity, Fast Transients and ESD) For continued compliance ensure that all input and output cables are wired with cable screen connected to Pin 1 of the XLR. The input XLR Pin 1 on BSS equipment is generally connected to chassis via a capacitor to prevent ground loops whilst ensuring good EMC compatibility. We have written this manual with the aim of helping installers, sound engineers and musicians alike get to grips with the DPR-402 and obtain its maximum capability. If you are new to BSS products, we recommend that you begin at the start of the manual. If, however, you are already familiar with the intended application, and just want to get the unit installed without delay, then follow the highlighted sections. [. . . ] There is no change in the general frequency response, yet sibilance is controlled. 12. 2 Broadband De-essing and controls Broadband de-essing can be achieved either simultaneously with normal compression on the same channel of the DPR-402, utilising DE-ESS and FREQ controls (See figure 12. 1a), or exclusively on the one channel by setting the MODE switch to DE-ESS WIDE, and utilising the compressor section controls (See figure 12. 1b). Fig 12. 1a DE-ESS Controls 25 De-essing and Peak Limiting Fig 12. 1b DE-ESS Controls In utilising the controls in figure 12. 1b, no other compressor controls will be required. If no compression is being used, the ratio or threshold controls should be set to OUT. The frequency control should be set to coincide with the lowest frequency of the sibilance, and the de-ess control be used to give the required amount of gain reduction. The dynamic settings for this compression are set automatically by the unit, and are optimised for general vocal work. The green and orange LEDs above the de-ess control provide a simple indication of the degree of de-essing, with the green LED indicating the start of the operation and the orange LED indicating approximately 15dB of gain reduction. Having only a frequency and level control for this broadband de-essing function provides a very simple and effective way of treating general sibilant vocal signals, when processed on their own. Should the need for more comprehensive control of the de-essing function arise, then the main compressor section can be configured to operate as a dedicated de-esser by operating the mode switch (See figure 12. 1b). The amount of gain reduction can then be extended down to 30dB if required, and this gives full control over the dynamic settings, as in normal compression (refer to section 14. 1). 12. 3 HF Only De-essing and Controls To achieve this mode of operation, the main compressor must be utilised as an exclusive de-esser by operation of the MODE switch to DE-ESS HF (See figure 12. 2). Gain reduction at high frequencies only is achieved by inserting an internal high pass filter into the subtract side chain so that only these high frequencies are available to the subtractor. The front panel FREQ control adjusts both this filter and the control side chain filter simultaneously, to provide a de-essing range from 700Hz to 20kHz. HF only de-essing is achieved by operating the compressor controls as for normal compression (refer to section 10), and utilising the FREQ control to allow only the sibilant frequencies to cause gain reduction. If general compression is required simultaneously, then channel 2 of the unit can be used by connecting the two channels in series. It should be remembered that in this mode, the DE-ESS and PEAK LIM controls must be set to OUT, as they cannot be used simultaneously with the compressor switched to dedicated de-ess mode. Fig 12. 2 HF DE-ESS Controls 26 To aid the correct setting of the FREQ control in relation to the audible sibilance, the source program can be listened to through the internal de-ess filter by depressing the MON S. C. This replaces the normal signal at the output connector with the output of the de-ess filter. The effect of de-essing at various frequencies on a program is shown in figure 12. 3. Fig 12. 3 Effect of de-essing on output 12. 4 Peak Limiting Referring back to section 3, the problems with high frequency transients causing distortion further down the equipment line were discussed. The peak limiter of the DPR-402 provides an extra stage of gain reduction, with dynamics specifically set for these fast transients. It is used in conjunction with the main compressor section and provides an output limiting function to control the fast transients which would generally be missed by the slower dynamic settings of the compressor. The attack and release times are set internally to suit the limiting application, with a choice of FAST or SLOW response selected by a switch on the rear panel (refer to section 9). It is preferable to use the FAST response setting, providing this does not cause audible distortion, otherwise the SLOW response should be used. The peak limiter threshold is unaffected by the GAIN control, and is set by the PEAK LIM control, which is scaled directly in dBv. A green LED is provided to indicate when limiting begins, and a red LED indicates when heavy limiting occurs (above 10dB) (See figure 12. 4). This red LED indicates that more than optimum peak limiting is being used, and the output gain control should therefore be backed off, so that it only flashes on occasional peaks. Fig 12. 4 PEAK LIMITER controls 27 Rear Barrier Strip 13. 0 Rear Barrier Strip The DPR-402s rear barrier strip provides an interface with the main compressor section, allowing for various configurations which utilise the internal facilities as well as external equipment. [. . . ] 10dB of gain reduction will occur at and above twice this frequency. Note 3: Facilities Mode Switch: Bypass Switch: MON S. C. Switch: Meter Input Switch: 3 position switch to select: Normal mode to allow simultaneous wide band de-essing, compressing and peak limiting. Bypasses all functions of the unit at unity gain, allowing all parameters to be adjusted and levels checked whilst 'on air'. Momentarily connects the control side chain to the output of the unit to allow monitoring of control insert return. [. . . ]