The dynamic Equalizer U781 is a special dynamics processor that controls boost or cut of an equalizer band depending on the input signal, either after passing the filter or not.
The function is similar to a compressor; however, many details are totally different. The dynamic equalizer is an effective tool for stereo mastering that can be used for dynamic global corrections of the frequency respone as well as for the oppression of disturbing frequencies or the accentuation of formants. In addition, the device can be used as DeEsser and for the dynamic variation of filter settings, similar to the characteristics of our niveau filters.
Very often, the sound of vocals is entirely different depending on the loudness of the singer, even when the level has been compressed very well. The spectrum of a loud voice changes from skirl and aggressiv to matte and dull with restrained singing. The dynamic equalizer makes possible to implement an automatic compensation of these effects. Using a narrow q-factor setting and a center frequency that affects the aggressive sounding formants of the voice in THRU mode with side chain POST FILTER, allows to find a setting that reduces this frequency band at higher levels and adds formants if the level is low.
The same basic setting in ABOVE mode allows the accentuation of formats as well as oppression of disturbing components.
DeEsser settings are also based on this setting. Using very short attack and release times with an optimized setting of the center frequency and the q-factor, results in fast and inaudible regulation of sibilants that will not cause any changes of the sound.
Another interesting application is the global variation the the mid range, depending on the level, if the mix is not not compressed down to a remaining dynamic of 1 dB. With BELOW mode, a center frequency of 800 Hz and very wide q-factor settings, the GAIN CHANGE control is adjusted to produce a small cut when the level drops below threshold that should be adjusted to a value, just below the average level of the mix. When the level drops a little, the dynamic equalizer reduces the entire mid range which is equal to a boost of the high and low range at a time. Optimizing this basic setting to the particular mix results in an aural compensation. Alternative, adding high frequencies with wide q-factor setting when the level drops, usually result in an improvement of the mix when used appropriately and unobstrusively.
The dynamic equalizer is a stereo device. The sweep range of the filter covers the entire audio band from 20 Hz to 20 kHz, divide into three ranges. The q-factor of the bell characteristic can be controlled over a wide range from several octaves down to a third.
The combination of a 3 position stepper switch for the frequency range and a pot controls the center frequency. Another pot controls the q-factor. Frequency and q-factor is adjusted manually. For easy adjustment of the filter, the TUNE switch routs the output of the filter directly to the output of the module.
While TUNE checks the filter setting always in band pass mode, the real EQ settings that are controlled dynamically with normal operated can be controlled in the MAN (manual) mode. If the OP-MODE switch is set to MAN, the gain change control operates similar to the boost/cut control of an equalizer and no dynamic regulation takes place.
The dynamic control works similar to the control section of an usual compressor. The input of this control section defaults to the input of the module. The POST FILTER switch movse the input of the control section post filter. With this setting, the filter operates always in band pass mode and works similar to a side chain filter. The regulation takes place only in the frequency band around the center frequency of the filter and the q-factor setting controls the band width of the regualation as well. This setting can be checked at the output of the device when the TUNE switch is pressed.
The Control Section
The control section has Threshold, Attack, and Release controls and an additional Gain Change control, which can be considered as a special kind of ratio control. While attack and release are not different from the controls of a normal compressor, the effect of the threshold and gain-change settings depends on the setting of the OP-MODE switch.
- more details on the dynamics Equalizer