AES: MOTU Debuts New Synth Plug-In for OS X

(Click for a close-up)

MOTU was demonstrating MX4 ($295), a new virtual instrument plug-in for MOTU DP4 (MAS), Pro Tools (RTAS) and other Mac OS X audio hosts (Audio Units). MX4 features a hybrid synthesis engine that combines several forms of synthesis, including subtractive, wavetable, frequency modulation (FM), amplitude modulation (AM) and analog emulation.

As a plug-in, MX4 operates efficiently and provides unlimited voices, polyphony and instantiations (subject to the processing resources of the host computer). Playback is sample-accurate with supporting host applications, such as Digital Performer 4. MX4's 32-bit internal resolution provides wide dynamic range, and it supports all standard sample rates up to 192kHz. All settings are saved with host software projects for instant recall.

MX4's basic synthesis architecture provides 3 oscillators with modulatable waveform symmetry and hard sync, 2 variable topology multimode filters, 4 variable waveshape LFO's and 4 ADSHR envelopes.

Oscillators

MX4 provides all standard analog synthesizer waveforms, but every waveform has adjustable symmetry. This allows users to create standard pulse width modulation effects, as well as waveform "morphing" effects, such as smoothly changing from a triangle waveform to a sawtooth. Changing the symmetry of simple sine waves can even create interesting and unique spectra.

Each of the three oscillators can use a wavetable instead of a standard waveform. Dozens of wavetables are supplied, and users can also create their own. The wavetable on each oscillator can be individually indexed, and symmetry can be applied to wavetables as well, for a wide array of timbres.

Oscillators 1 and 2 can be synced together to create the same hard sync effects found on classic analog polysynths such as the Sequential Circuits Prophet-5 and Moog Memorymoog.

Oscillator 3 serves as a frequency modulation (FM) source for other oscillators -- or the filter cutoff frequency. Because oscillator 3 includes all waveforms, as well as the wavetable and symmetry features found on the other oscillators, it can produce a wide array of modulation effects that extend from LFO rates into the audible range.

In addition to the three oscillators, an independent fundamental-tone oscillator and ring modulator are also included to further extend the oscillator section.

Filters

Two resonant multimode filters (with modulatable overdrive) provide low-pass, high-pass, band-pass and notch filters with independent slope specified as 6, 12, 18 or 24dB per octave for a total of 16 different filter types. As a result, users can create a wide variety of vintage keyboard sounds. Both filters can also be stacked, combining them for a total of 48dB per octave.

MX4's Variable Filter Topology allows users to easily and intuitively arrange the two filters and overdrive in 14 different configurations that produce over 3,000 different filter topologies. Users can then further adjust the filter settings, providing a very wide range of filter effects to explore.

Modulation architecture

The four variable waveshape LFOs include adjustable symmetry, rate delay, fade and phase. Four ADSHR envelopes are also provided, with graphic controls for intuitive programming. All parameters can be modulated.

Flexible modulation routings are essential for expanding the sonic palette of a subtractive synthesizer such as MX4. All continuously variable parameters, including LFO's and envelopes, can be modulated by many sources, including track automation, MIDI controllers, LFO's & envelopes. They can even be modulated by multiple sources simultaneously.

Conversely, each modulation source in MX4 can modulate an unlimited number of destinations simultaneously, with the modulation range independently scaled at each destination. The provides modulation flexibility rarely seen outside of a modular synthesizer - but without the associated complexity. A user can click a modulation source, and MX4 displays the range of all parameters it is modulating. The filters and envelopes display the modulation range both on the knob itself and on the graphical representation. Modulation routings are clearly displayed in the MX4 window so users do not have to search through multiple pages or windows.

MX4 is expected to ship in Q4, 2003. Price is $295.