- Mix (Dry-Wet)
- mixes the input signal with the (filtered) output signal
- controls the level of the low-pass filter
- 250, 350, 500, 700, 1000, 1400, 2000, 2800
- control the levels of the filters with the given frequencies (in Hz)
- controls the level of the high-pass filter
The MOTM-450 Fixed Filter Bank is an improved version of the classic Moog 907A Filter Bank. The MOTM-450 contains 8 bandpass filters, a lowpass filter and a high-pass filter. Instead of bulky inductors and hand-matched capacitors used in the '907A, the MOTM-450 uses a special class of active filters called a FDNR (pronounced FUD-NER), which stands for Frequency Dependent Negative Reactance. The FDNR simulates the phase response as well as the frequency response of the LRC Moog circuit. Other fixed filter banks use more 'standard' filter topologies, which do NOT sound the same as the FDNR/Moog 907A circuitry. The disadvantage is that the FDNR requires 3X more parts, which explains the relative higher cost of the MOTM-450 module. However, the sonic quality difference is obvious, as is the 12dB lower noise floor compared to other fixed filter banks (that's 4 TIMES lower).
The controls include a WET/DRY mix (like on the MOTM-410) and a manual/remote IN/OUT bypass. An LED indicates EQ IN use. The module has an expansion connector that will allow individual, buffered outputs and envelope followers on a future 2U wide MOTM-451 Companion Module.
It is important to note that this is NOT a 'graphic equalizer'. The MOTM-450 uses bandpass filters (not cut/boost filters) which are normalized for unity gain. This means that if all frequency knobs are at 0, no sound comes out. If all knobs are at '10', you have basically a wire. The way to think about it is as follows: a knob accents that frequency range only. This makes the MOTM-450 ideal for vocal formants and other such processing. Any line-level audio signal can be fed through the module, not just MOTM audio signals.