Software synthesizer

A software synthesizer, also known as a softsynth, or software instrument is a computer program, or plug-in that generates digital audio, usually for music. Computer software that can create sounds or music is not new, but advances in processing speed now allow softsynths to accomplish the same tasks that previously required the dedicated hardware of a conventional synthesizer. Softsynths are usually cheaper and more portable than dedicated hardware, and easier to interface with other music software such as music sequencers.

Types of software synthesizers

Bristol Mini
Bristol Mini soft-synth

Softsynths can cover a range of synthesis methods, including subtractive synthesis (including analog modeling, a subtype), FM synthesis (including the similar phase distortion synthesis), physical modelling synthesis, additive synthesis (including the related resynthesis), and sample-based synthesis.

Many popular hardware synthesizers are no longer manufactured, but have been emulated in software. The emulation can even extend to having graphics that model the exact placements of the original hardware controls. Some simulators can even import the original sound patches with accuracy that is nearly indistinguishable from the original synthesizer. Popular synthesizers such as the Minimoog, Yamaha DX7, Korg M1, Prophet-5, Oberheim OB-X, Roland Jupiter 8, ARP 2600 and dozens of other classics have been recreated in software.

Some softsynths are heavily sample-based, and frequently have more capability than hardware units, since computers have fewer restrictions on memory than dedicated hardware synthesizers. Some of these sample based synthesizers come with sample libraries many gigabytes in size. Some are specifically designed to mimic real world instruments such as pianos. Many sample libraries are available in a common format like .wav, .sf or .sf2, and can be used with almost any sampler-based softsynth.

The major downside of using softsynths can often be more latency (delay between playing the note and hearing the corresponding sound). Decreasing latency requires increasing the demand on the computer's processor. When the soft synthesizer is running as a plug-in for a host sequencer, both the soft synth and the sequencer are competing for processor time. Multi-processor computers can handle this better than single-processor computers. As the processor becomes overloaded, sonic artifacts such as "clicks" and "pops" can be heard during performance or playback. When the processor becomes completely overloaded, the host sequencer or computer can lock up or crash. Increasing buffer size helps, but also increases latency. However modern professional audio interfaces can frequently operate with extremely low latency, so in recent years this has become much less of a problem than in the early days of computer music.

It is also possible to generate sound files offline, meaning sound generation does not have to be in real time, or live. For example, the input could be a MIDI file and the output could be a WAV file or an MP3 file. Playing a WAV or MP3 file simply means playing a precalculated waveform. The advantage of offline synthesis is that the software can spend as much time as it needs to generate the resulting sounds, potentially increasing sound quality. It could take 30 seconds of computing time to generate 1 second of real-time sound, for example. The disadvantage is that changes to the music specifications cannot be heard immediately.

Often a composer or virtual conductor will want a "draft mode" for initial score editing, and then use the "production mode" to generate high-quality sound as one gets closer to the final version. The draft mode allows for quicker turn-around, perhaps in real time, but will not have the full quality of the production mode. The draft render is roughly analogous to a wire-frame or "big polygon" animation when creating 3D animation or CGI. Both are based on the trade-off between quality and turn-around time for reviewing drafts and changes.

Software instrument

Cubase 6 feature - software instruments and software effects
top: Software instruments
  • HALion Sonic SE sample player
  • Groove Agent ONE drum sample player
bottom: Software effect processors
on Cubase 6 (CC-BY-SA-3.0 image)

A software instrument can be a synthesized version of a real instrument (like the sounds of a violin or drums), or a unique instrument, generated by computer software. Software instruments have been made popular by the convergence of synthesizers and computers, as well as sequencing software like GarageBand, Logic Pro (geared toward professionals), the open source project Audacity, and Ableton Live which is geared towards live performances. Also of note is software like Csound and Nyquist, which can be used to program software instruments. A software instrument is akin to a soundfont.

Plugin compatibility

Stand-alone softsynths run as a program on the computer so additional software is not required. Plugin softsynths require a host application such as a digital audio workstation, which records the music that is played. Common plugin technologies include VST, AU, and LADSPA.

Comparison of software synthesizers and digital hardware synthesizers

Software synthesizers can have more advanced algorithms than digital hardware synthesizers due to the much greater processing speed (as well as support for floating point processing and greater than 24-bit word size) of the x86-64 CPUs that modern music production personal computers have over the digital signal processors found in common hardware synthesizers. The advantage to dedicated hardware is that it can be more stable, and also that it often has a user interface that is physical (knobs and sliders) and therefore easier to manipulate during performances. Many softsynths use mathematical algorithms that directly emulate the electronic components and circuitry of the original hardware synthesizer. This produces an exceptionally authentic sound, even capturing flaws in the original hardware, such as oscillator drift caused by thermal sensitivity of the components.

Typical software synthesizers

  • Sonic Academy ANA & ANA2
  • Spectrasonics Omnisphere 2[1]
  • U-He Diva
  • Xfer Records Serum
  • UVI Falcon
  • Lennar Digital Sylenth1
  • Massive, Reaktor 6 and FM8 by Native Instruments
  • Waldorf Largo
  • Synapse Dune 3

Software Synth developers such as Arturia offer virtual editions of analog synths like the Minimoog, the ARP 2600, as well as the Yamaha CS-80. Gforce produces a Minimoog with sounds designed by Rick Wakeman and version of the ARP Odyssey.

Linux synthesizers

ZynAddSubFX is an open-source software synthesizer for Linux, macOS and Windows. It can generate polyphonic, multitimbral, microtonal sounds in realtime.[2] It is a free program, licensed under version 2 of the GNU General Public License.

There are many other open-source software synthesizers available for free for unix-based operating systems, including amsynth, Hexter, TAL NoizeMaker, Xsynth, Wsynth, WhySynth, Add64, OBXD, Mx44, Phasex, Alsa Modular Synth, Bristol and others still.

Microsoft GS Wavetable SW Synth

The Microsoft GS Wavetable SW Synth (based on sample-based synthesis) included in versions of DirectX as an integral part of DirectMusic is a version of the Roland Virtual Sound Canvas with GS sound set licensed by Microsoft from Roland Corporation in 1996.[3] The file containing the samples is in DLS format.

Mobile synthesizer

The integrated processors included in mobile phones have become so fast, that synthesizer applications (apps) can play with the same capabilities as the classic analog or digital synths. They can have several oscillators with pulse-width modulated waveforms, frequency- and amplitude- modulation, ADSR envelope forming, and a number of digital sound processing effects like filter, exciter, delay, chorus and reverb. One example is the Windows Phone Synthesizer.

Recently, there have been many virtual synthesizers released for Apples iOS devices (iPad, iPhone, and iPod Touch). Many of these are from independent developers. Hardware manufacturers have also released apps for the iPad and iPhone including Moog Music, Korg, Roland Corporation, Akai and Tascam.

Apple Logic Studio comes with a variety of Software Synths including FM, Bass, Analog, Ensemble as well as Electric Piano and Hammond B-3 emulation.

List of some of the earlier softsynths for PC

  • Audio Simulation AudioSim (DOS, 1996)
  • AXS (Analogue Xpansion System) (DOS, 1998)
  • Orangator (Windows 95/98, 1998)
  • SimSynth 2 (Windows 95/98, 1998)
  • Synoptic Probe (Windows 95/98, 1999)
  • Microsoft GS Wavetable SW Synth (featured in Windows 98 and later versions of Windows)

See also


  1. ^
  2. ^ "ZynAddSubFX project page at Sourceforge". Retrieved 31 July 2012.
  3. ^ "Microsoft Licenses Sound Canvas Sounds From Industry Leader Roland Corp". Microsoft Corp. 22 October 1996. Retrieved 23 July 2009.

External links

Audiosim (software synthesizer)

AudioSim is a virtual analog software synthesizer. It was released in 1996 by the German-Hungarian software company Audio Simulation. It was first available for DOS and supported SoundBlaster or Gravis Ultrasound Sound cards.

B4 Organ II

The B4 Organ II is a discontinued commercial, proprietary software synthesizer made by Native Instruments. The software runs as a stand-alone executable, or as a VST, DXi, or RTAS plugin in a Digital audio workstation. The software is an example of a "Clonewheel organ", an attempt at recreating the sound of a Hammond organ using software synthesis.

Dave Smith (engineer)

Dave Smith is an engineer and musician and founder of the synthesizer company Sequential. Smith was responsible for the first commercial polyphonic and microprocessor-controlled synthesizer, the Prophet-5, and later the multitimbral synthesizer. He is also referred to as the "Father of MIDI" for his role in the development of MIDI, now a standard interface protocol for electronic instruments and recording/pro audio equipment.

Disposable Soft Synth Interface

Disposable Soft Synth Interface (DSSI) is a virtual instrument (software synthesizer) plugin architecture for use by music sequencer applications. It was designed for applications running under Linux, although there is nothing specific to Linux in the interface itself. It is distributed under the terms of a combination of GNU Lesser General Public License and some BSD licenses, all of which are free software licences.

E-mu Systems

E-MU Systems was a software synthesizer, audio interface, MIDI interface, and MIDI keyboard manufacturer. Founded in 1971 as a synthesizer maker, E-mu was a pioneer in samplers, sample-based drum machines and low-cost digital sampling music workstations.

After its acquisition in 1993, E-mu Systems was a wholly owned subsidiary of Creative Technology, Ltd.

In 1998, E-mu was combined with Ensoniq, another synthesizer and sampler manufacturer previously acquired by Creative Technology.

E-mu was last based in Scotts Valley, California, on the outskirts of Silicon Valley.

Elektrik Piano

Elektrik Piano is a sample-based software synthesizer developed by Native Instruments. The instrument is an emulation of four "classic" electric pianos – the Fender Rhodes MKI and MKII, the Hohner Clavinet E7 and the Wurlitzer A200.It was originally released in May 2004. The latest version, 1.5, was released in April 2007.


FluidSynth, formerly named iiwusynth, is a free open source software synthesizer which converts Musical Instrument Digital Interface (MIDI) note data into an audio signal using SoundFont technology without need for a SoundFont-compatible soundcard. FluidSynth can act as a virtual MIDI device, able to receive MIDI data from any program and transform it into audio on-the-fly. It can also read in SMF (.mid) files directly. On the output side, it can send audio data directly to an audio device for playback, or to a Raw or Wave file. It can also convert a SMF file directly to an audio file in faster-than-real-time. The combination of these features gives FluidSynth the following major use cases:

Synthesizing MIDI data from another application directly to the speakers,

Synthesizing MIDI data from another application, recording the output to an audio file,

Playing a MIDI file to the speakers,

Converting a MIDI file to a digital audio file.The size of loaded SoundFont banks is limited by the amount of RAM available. There is a GUI for FluidSynth called Qsynth, which is also open source. Both are available in most Linux distributions, and can also be compiled for Windows. Windows binary installers are not distributed alone, though it is bundled with QSynth.

It features microtonal support and was used in the MicrotonalISM project of the Network for Interdisciplinary Studies in Science, Technology, and Music. A Max/MSP plugin is available from IRCAM.The core synthesizer is written as a C library with a large application programming interface (API). Partial bindings for Python, Ruby, Haskell, and .NET Framework are available.

Korg Kronos

The Kronos is a music workstation manufactured by Korg that combines nine different synthesizer sound engines with a sequencer, digital recorder, effects, a color touchscreen display and a keyboard. Korg's latest flagship synthesizer series at the time of its announcement, the Kronos series was announced at the winter NAMM Show in Anaheim, California in January 2011.Much like Kronos' predecessor and Korg's previous flagship synthesizer workstation, the OASYS, Kronos is basically a custom software synthesizer running on an Intel x86 processor and operating system based on the Linux kernel with RTAI extensions; it includes 9 different sound engines which encompass the entire range of Korg synthesis technologies.The Kronos X was introduced in July 2012 with OS version 2 and the Kronos 2 with OS version 3 was announced in November 2014 (marketed as "new Kronos"). Updated versions have more memory and new factory sounds, but otherwise have similar hardware based on the Intel Atom processor series, so older models can be upgraded to the newer specs with user-installable OS updates and sound banks.

List of Linux audio software

The following is an incomplete list of Linux audio software.

NI Massive

Massive is a commercial wavetable software synthesizer plugin manufactured by Native Instruments for use in professional audio production. It utilizes several wavetables and oscillators in the creation of synthetic timbres. The software can be used as a VST plugin within a digital audio workstation, or as a standalone program. Released in 2007, the plugin has gained widespread popularity in the electronic music field, and is one of the most popular synthesizer plugins for modern dance music production.


Pianoteq is a software synthesizer that features real-time MIDI-control of digital physically modeled pianos and related instruments, including electric piano, harp, harpsichord, fortepiano, and various metallophones. It is usable as a stand-alone program for Microsoft Windows, Mac OS X and Linux (including ARM architecture) platforms, or as a plug in for VSTi hosts and two VSTi counterpart for use with digital audio workstations.

ReBirth RB-338

ReBirth RB-338 is a software synthesizer for Microsoft Windows, Mac OS 8-9 and iOS for the iPhone, iPod Touch and iPad. It was developed by Propellerhead Software, and its first alpha version (for Mac OS) was publicly released in December 1996. Propellerhead Software ceased developing the original program in January 1999. Support for desktop versions was officially discontinued in September 2005. Shortly afterward, the ReBirth Museum Web site was launched and the last desktop version's (2.0.1) disk image was made available as a free download. Propellerhead Software continues to develop other software relating to dance-oriented computer-based music composition, including Reason, its flagship software synthesizer, as well as portable "app" versions of ReBirth.

ReWire (software protocol)

ReWire is a software protocol, jointly developed by Propellerhead and Steinberg, allowing remote control and data transfer among digital audio editing and related software. Originally appearing in the ReBirth software synthesizer in 1998, the protocol has since evolved into an industry standard.

Currently used in macOS and Microsoft Windows 32-bit or 64-bit audio applications, ReWire enables the simultaneous transfer of up to 256 audio tracks of arbitrary resolution and 4080 channels of MIDI data. This allows, for example, the output from synthesizer software to be fed directly into a linear editor without the use of intermediate files or analog transfers. There are also provisions to remotely trigger actions, such as starting and stopping recording. The protocol is licensed free of charge to companies only, but comes with a "non-disclosure of source code" license that is incompatible with most free-software licenses.

The ReWire system consists of "Mixers", "Panels", and "Devices". Mixers are the host applications which typically do the sequencing at one end and the final mixdown at the other end. A Device is a dynamic link library that only generates sound; it has no user interface. A Panel is a graphical interface for setting the parameters of one Device. A typical setup would be to use Ableton Live in "Mixer" mode, and use Propellerhead Reason as a synthesizer. In this case Reason would provide Device/Panel pairs to Ableton, which could then send midi commands, sync timing and mix Reason's output into its own effects chains. Many applications support either mode. In fact, an application could (at the discretion of a developer) act as both a Mixer and a Panel at the same time.


Rosegarden is a free software digital audio workstation program developed for Linux with ALSA and Qt4. It acts as an audio and MIDI sequencer, scorewriter and musical composition and editing tool. It is intended to be a free alternative to such applications as Cubase.

Software synthesizer is available as a plugin, and it is possible to use external MIDI synthesizer, hardware or software (such as FluidSynth or TiMidity++) in order to make any sound from MIDI compositions. Recent versions of Rosegarden support the DSSI software synthesizer plugin interface, and can use some Windows VST plugins through an adapter.

Software sampler

A software sampler is a piece of software which allows a computer to emulate the functionality of a sampler.

In the same way that a sampler has much in common with a synthesizer, software samplers are in many ways similar to software synthesizers and there is great deal of overlap between the two, but whereas a software synthesizer generates sounds algorithmically from mathematically-described tones or short-term waveforms (i.e., less than 100 ms in length), a software sampler always reproduces samples, often much longer than a second, as the first step of its algorithm.


Sytrus is a software synthesizer included in the Digital Audio Workstation FL Studio. Image-Line also released VSTi and DXi versions.

Virtual Studio Technology

Virtual Studio Technology (VST) is an audio plug-in software interface that integrates software synthesizer and effects in digital audio workstations. VST and similar technologies use digital signal processing to simulate traditional recording studio hardware in software. Thousands of plugins exist, both commercial and freeware, and a large number of audio applications support VST under license from its creator, Steinberg.

Virtual instrument

Virtual instrument may refer to:

A Software synthesizer, a computer program or plug-in that generates digital audio

A program that implements functions of an instrument by computer, sensors and actuators, see Virtual instrumentation

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