Wednesday, February 26, 2014

Xen-Arts Virtual Instrument Announcement | Xen-FMTS 2

proudly presents
Xen-FMTS 2
An FM Synthesis VSTi for the Creation of Microtonal and Xenharmonic Music

Xen-FMTS 2 is a 4 Operator FM Synthesis VSTi with a specialized set of features for computer musicians interested in exploring the vast expressive possibilities of making music with alternative intonation systems. It is a freeware 32-bit plugin instrument for Windows that includes 115 patches, 55 microtunings and 56 partials files. 

Microtuning Features
  • Internally loads and externally receives both MTS (MIDI Tuning Standard) Bulk Dump and Single Note Microtuning Files 
  • Operator ratios can easily be set to values that are coincident with the microtuning being used, thereby producing intonation related sidebands in the timbre of the instrument 
  • Microtonal pitch-bend ranges may be configured in cents, harmonics and superparticular ratios 
  • Arbitrary microtonal pitch shifting makes it possible to easily pitch transpose the oscillators in both octave and non-octave increments 
FM-RM Oscillator
  • 4 Operator FM Synthesis with Ring-Modulation 
  • 57 Operator Algorithms 
  • 11 different Operator Waveforms 
  • Analog Pitch Drift Emulator 
  • Transposition by cents offsets 
  • Partials text files may be used to quantize the frequency ratios of the operators to user specified values 
  • Velocity-to-Harmonics Modulation enables oscillators to dynamically sound harmonics of the fundamental pitch
  • Seven dedicated hybrid modulators for Operators A, B, C, D, Filters, Amplifier and Pitch 
  • Each modulator includes an ADSR style envelope generator, and an LFO which can be switched to run at audio-rate 
  • Each ADSR Envelope Generator features Per-Stage Keyboard Tracking 
  • LFOs can either be synchronized to the host DAW tempo or set in Hertz. They include 24 Waveforms, a Slewer and can be switched to run at audio-rate 
Filter Section
  • Pre-Filter Saturation Stage with 20 Saturation Types 
  • Two Independent Filters with Six Filter Types: LP4, LP2, HPF, BPF, BRF, APF 
  • One and Two Stage Filter Cascade 
Performance Control 
  • Full controller MIDI Pitch Microtuning with MTS (MIDI Tuning Standard) 
  • MTS Support for both Single Note and Bulk Dump 
  • Loads MTS Microtuning Format Files Internally and Receives MTS Externally 
  • Local (Per-Patch) and Global Microtuning (Static Microtuning for All Patches) 
  • Microtunings can be loaded from any directory on hard drives or storage devices connected to the PC 
  • 12 Note Polyphonic 
  • Monophonic Legato Mode 
  • Monophonic Portamento 
  • Microtonal Pitch Bend 
  • Vibrato 
  • Effects include Chorus, Lowpass Filter Cascade (Warm Filter) with 6 dB to 48 dB per-octave filters and Stereo Ensemble 

Please note that Xen-Arts software never has been, and never will be, infected with computer viruses; this we promise. If your virus software ever indicates that our microtonal music software has a virus, this is what is known as a False Positive. Contacting the developer of your virus software to make them aware of the false positive is the best solution.

Xen-FMTS 2 Development Notes:
This iteration of our popular Xenharmonic FMTS VSTi features many new and exciting enhancements over the original, some of which were suggested by our users and development group:

A common comment about version 1 was that the user interface was too large for small monitors and laptop screens. In response to this user feedback, the interface was completely redesigned making it much smaller than before, which is now at 943 x 652 pixels.

Among the many new features are the Modulators, which include an ADSR-style envelope generator, and an LFO which can be switched to run at audio-rate. There are seven of these dedicated hybrid modulators for Operators A, B, C, D, Filters, Amplifier and Pitch. With the LFOs running at audio-rate, the pitch is controlled by the MIDI-to-CV and the loaded MTS Microtuning file; transforming the LFO into a pitch-accurate microtonal-controlled oscillator, which is in turn capable of introducing microtuning related sideband spectra into the composite synthesizer signal.

In the instrument's Performance Control section, numerous improvements have been made, which include new MIDI Pitch Bend modes that enable users to specify precise bend ranges in either Cents, Harmonics or Superparticular Ratios. A Chorus effect has also been added, as well as a more versatile LPF cascade on the Ensemble page (a kind of tone control, formerly called Warm Filter).

In the FM-RM Oscillator section of the synthesizer, randomization and reset features have been added to two of the partials selection pages, as well as the ability to either multiply or divide the pitch of an operator by the selected frequency ratio. The completely redesigned Iso-Index page now includes an Op Rotate feature for rerouting the frequency ratios to other operators.

The Pitch page of the FM-RM Oscillator now features Velocity-to-Harmonics Modulation, where playing force through MIDI velocity is able to break out harmonics of the fundamental pitch. Another very important enhancement in the Pitch section is the inclusion of a full-featured Pitch EG that shares many common features of the other Modulators.

This version of the instrument also features the same versatile filter section that is found in two of our other instruments: Ivor and XenFont.

Please feel free to share your comments, perceptions, experiences - and especially music made with this instrument - either in the comments of this post, or through email.

Music featuring the Xen-FMTS VSTi

Xen-FMTS 2 • The Sidebander • ARO Demo

A short FM-geek timbre demonstration of the Xen-FMTS 2 LFOs running at audio rate. There are seven dedicated hybrid modulators for Operators A, B, C, D, Filters, Amplifier and Pitch. Each modulator includes an ADSR style envelope generator, and an LFO which can be switched to run at audio-rate. With the LFOs running at audio-rate, the pitch is controlled by the MIDI-to-CV and the loaded MTS Microtuning file; transforming them into pitch-accurate microtonal-controlled oscillators, which are in turn capable of introducing microtuning related sideband spectra into the composite synthesizer signal.

It is likely self apparent that when doing one's own custom sound-design, it's not necessary to set all of the LFOs to run at audio rate, which as shown in the above demo, quickly creates a pretty dense spectral forest. This is more to show that complex timbres can be generated from extremely simple sources - i.e. - in this case sinewaves.

To those kind individuals who have donated, thank you very much.

What is microtuning? 

Microtuning, just-intonation, microtonality, temperament and xenharmonics, are all terms indicating the practice of being able to change the underlying intonation systems of musical instruments, typically to something other than the standard Western 12-tone-equal-temperament. Even though 12-ED2 is an intonation system of self-evident great beauty and musical utility, it is but one member in a huge continuum of possibility for musical instrument intonation. 

You are all warmly invited to download the free instruments on offer at this site - which place microtuning features front-and-center in the instrument's designs - to explore these sounds and learn about the use of alternative intonation systems, as each instrument includes a nice basic set of tunings as a basis for getting started.

Thanks to Aleksey Vaneev at Voxengo for his free Span frequency analyzer, which was featured in the above video demonstration.

from standingwave via soundcloud:

Observe the sounds at 0:40 and especially starting at around 0:45...


[Send more Xen-FMTS 2 user demo links via the Xen-Arts blog email contact information above.]


  1. A thousand thank-yous to Jacky, for developing all this amazing software!! With this outstanding re-imagining of Xen-FMTS, we can all journey deeper into a xenharmonic and xentimbral fantasy land.

    It's obvious from only a short time of using Xen-FMTS 2, that this synthesizer has enormous sound design potential at every level. Not only that, but FMTS 2 (and your other software for that matter) has a unique sound of their own. Many of us are looking for just that uniqueness!

    Because of this, the sounds of Xen-Arts plugs have been all over my work since the first one came out. In fact, I've been slowly retiring VSTs in my setup - VSTs I paid good money for! - as you continue to bring out amazing and new free softsynths.

    One thing I really like about FMTS 2 is modulation with the audio-rate oscillators. These can be tuned to *any interval above or below the fundamental of the note*!! So not only do you get the standard 4-op FM/RM algorithms but you have several audio-rate amplitude modulators hidden all over the place. Even the filter cutoff can be modulated at audio rate. When I first played with the synth, I used this audio-rate modulation of the filter cutoff to make glassy inharmonic smashing sounds. Another time, I started with a standard FM-bell type sound, then applied audio-rate modulation to the VCA's gain - this transformed the bell into a picked guitar/bass sound. I couldn't believe it. Sounds like physical modelling, from what appears to be just another FM synth...

    The world already has a few powerful FM synths. FMTS 2 can now join them. But because it is built with xentimbral explorations in mind, for me there is nothing better. Jacky here understands the kinds of arcane features that microtone-savvy composers need.

    Jacky, I am humbled by your many deeply-considered contributions to music. Thanks again for sharing your software with the world. I hope these synths are one day recognized as cult classics!!

  2. Thank You very much!

  3. Can't get it to work in Reaper

  4. Hi LJP,

    If you are on Windows 7, try running Reaper as an administrator...

    Click on the Start menu / All Programs. Locate the Reaper program icon, right-click on it and select Run As Administrator.

    This only has to be done once, and it enables the host and plugin to write to its content directory, which is otherwise blocked by User Account Controls. This is the most common fix for people on about any kind of host: Ableton Live, Reaper, Sonar, Podium, Cubase.

    Let me know how it goes.

  5. the controls seem novel to me, from what synths would you say this one draws inspiration from? i'm looking for a way in to understanding the functions of this fantastic sounding instrument.

  6. Hi Anonymous,


    The oscillator of Xen-FMTS is similar in some ways to the Yamaha TX18Z, but the controls are my own design and come from a modular synthesis perspective. This particular instrument is a kind of hybrid of FM and subtractive synthesis though, and whereas the old TX81Z had no filters, this one does, as well as many other features that expand the sound from mere FM alone.

    As mentioned above by Sean, an important concept in this synth design is the ability to do very controlled audio-rate modulation of the operator amplitude, filter cutoff, pitch and VCA, which as documented in the manual, is able to generate sidebands in the signal. This is also quite different from the old TX81Z.

    If there are specific facets of the synths functions that you would like to learn more about, please feel free to let me know here in the comments, or otherwise through private email. I can type about how things work, but can also make some videos if needed.

    Very glad to know that you have enjoyed the sound of the synth. It's a deep refinement to the first version on about every level.