Audified has released the RZ062 Equalizer, a plug-in bundle based around models of scarce and sought-after 1960s vintage Klangfilm RZ062a and RZ062b valve EQ modules made by Siemens for installation in its film sound Universal Mixing and Control Console (Klangfilm System).
Now available as AU, AAX and VST plug-ins, the RZ062A and RZ062B are aimed and mixing and mastering with DAWs, a rare working pair of original hardware units recently changed hands for US$12,000.
‘In the field of studio equipment, the position occupied by the Mixing and Control Console is one of key importance, since the facilities with which it is equipped largely determine the extent to which the sound engineer is able to cope with the manifold tasks of effective tone control,’ says Klangfilm System sales literature from the era. ‘It can be supplied initially equipped with a minimum of facilities, and built out later to increase its flexibility or adapt it to changed working conditions (eg for stereophonic recording). Fully equipped, the Mixing and Control Console for 6 x 1 channels with 6 x 2 selective inputs contains and adjustable equaliser for individually boosting or suppressing the high and low frequencies (+12dB to -24dB at 40Hz and 10kHz), or for rotation around the middle frequency.’
The Klangfilm RZ062a and RZ062b valve EQ modules were designed to allow arbitrary modification of frequency response in sound recording and reproduction in order to correct studio acoustics, or create certain acoustic impressions or tonal colouring. Creatively, each module differed in its implementation of the central knob…
The RZ062a’s mid control rotates the entire frequency curve around a central (650Hz) point – treble frequencies are simultaneously lowered when the bass frequencies are raised, while the RZ062b module is even more complicated; its presence knob lets users choose one of four frequencies (1.4kHz, 2kHz, 2.8kHz and 4kHz) and adjust their gain simultaneously. Soon both modules made themselves seen and heard in high-end European studios of the time.
Each plug-in is modelled on an original device. Both provide adjustment of treble and bass but differ in the function of the mids control. The mid handle of RZ062A rotates the entire frequency curve around the central point. RZ062B is equipped with a presence knob that adjusts one of four preset frequencies. The RZ062 Equalizer is also equipped with Input and Output level knobs, and a Set Calibration function to give the user complete control over its pleasant-sounding Saturation. RZ062 Equalizer sounds superb on vocals, bass, and drums. It also allows users to work in Linked mode, control left and right channels independently, or switch to the MS (mid-side) mode that makes it a great tool for mastering.
In creating the plug-ins, Audified emulated more than 200 circuit components, including three triodes, plus input and output transformers: ‘We used so-called white box modelling. This means that we described the whole circuit with math equations based on the circuit analysis,’ says Audified Lead Programmer, Jarda Mačák. ‘Eventually, the overall model was fine-tuned by measurements and a component values-fitting algorithm to find the closest model to the real device as possible. That’s the trickiest part – finding a suitable real-time implementation of the model. We’ve got a really precise model, but no-one would be happy if it sucked up all available CPU resources to run just one instance of the plug-in in any given session.’
‘I would put it anywhere where there is a need to add more bass, highs or mids,’ says composer/producer Boris Carloff, the driving force behind the plug-in. ‘It is wasting its potential to use it for cutting frequencies since this is mastering-quality EQ. Its colouration is what makes it so unique. You can really sweeten things, and it is well known as the best voice EQ ever.’
