Software synthesizer

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A software synthesizer, also known as a softsynth or virtual instrument is a computer program for digital audio generation. Computer software which can create sounds or music is not new, but advances in processing speed are allowing softsynths to accomplish the same tasks as dedicated hardware. Softsynths can be cheaper and more portable than dedicated hardware, and easier to interface with other music software such as music sequencers.

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[edit] Hardware versus software

Dedicated hardware synthesizers can have software as complex as a soft synth. The distinction is that softsynths run on a general purpose computer with a sound card, and the hardware (dedicated) synthesizers have the custom software built-in. 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 which directly emulate the electronic components and circuitry of the original hardware synthesizer. This results in an exceptionally authentic sound, as well as allowing for some of the inconsistencies, such as oscillator drift caused by the thermal sensitivity of the components, to be added.

[edit] Types of softsynths

One common type of softsynth is a simulator (note - emulators are hardware devices, simulators are done with software). There are a number of very popular synthesizers which are no longer manufactured. While some can be purchased second hand, many are expensive and temperamental. The emulation can even extend to having graphics that model the exact placements of 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 and Yamaha DX-7, Korg M1, Prophet V, Oberheim OB-X, Roland Jupiter 8, ARP 2600 and dozens of other classics have simulators.

Some softsynths are heavily sample based. 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 files, and can be used with almost any sampler based softsynth.

In comparison, a simulator, which uses modeling algorithms, are heavily processor based. The downside being 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 in 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 will help, but also increase latency. Sample based soft synths do not tax the processor anywhere near as much as simulators, therefore being less at risk to latency issues, but can also crash the computer or host sequencer if adequate memory does not exist. Fortunately, at the time of this edit, memory is quite cheap and easily obtained for computers that are capable of being upgraded.

Another way of categorizing types of softsynths are by the way they run on the computer. Stand-alone softsynths run as a program on the computer, native to its operating system so additional software is not required. Plug-in softsynths require a host application such as a sequencer, which records the music that is played, or a "wrapper" which allows the plug-in to function as if it were a stand-alone soft synth (please note that a "wrapper" can also be a plug-in to allow a softsynth to run on a host sequencer that does not natively support its format, i.e. running a VST plug-in in a sequencer that only supports RTAS as its native format). Fortunately, many softsynths will function as both a plug in and a stand-alone.

[edit] Plug-in compatibility

It is common for recent softsynths to be compatible with technology such as Virtual Studio Technology (VST), which allow other music software to interface with the softsynth. Plug-in technologies include VST, DirectX instrument (DXi), Motu Audio System (MAS), Audio Units (AU), and Real Time AudioSuite (RTAS).

[edit] Typical software synthesizers

Among the multitude of software synthesizers the most widely known two are S-YXG series from YAMAHA and Virtual Sound Canvas presented by Roland under the name EDIROL.

[edit] S-YXG series

S-YXG100plus is the latest one in S-YXG series in Windows 9x. Essentially, the software is a VxD driver which emulates a synthesizer by utilizing a CPU to process MIDI signals with a wavetable file loaded into memory as a sound library. Different with those S-YXG variables in Windows 9x, S-YXG50 - the latest one in Windows NT - is a WDM driver in essence instead. S-YXG50 (WDM) is known to be of two sound libraries in which one is a wavetable of 2 MiB in size and the other 4 MiB. Both of the versions can be downloaded from Microsoft’s Windows Update Catalog site free of charge.

[edit] Virtual Sound Canvas

[edit] Microsoft GS Wavetable Synth

The Microsoft GS Wavetable Synth or the recently called Microsoft GS Wavetable SW Synth included in versions of Direct X as an integral part of DirectMusic is an antediluvian version of the Roland Virtual Sound Canvas with GS sound set licensed by Microsoft from Roland in 1996[1]. The wavetable file about 3 MiB in size is named "gm.dls" which tells us that the wavetable is in DLS format - a universal one contrasting Creative Technology's proprietary SoundFont.

[edit] QuickTime Music Synthesizer

QuickTime Music Synthesizer licensed by Apple Inc from Roland in 1997[2] is almost identical to Microsoft GS Wavetable Synth.

[edit] Korg Oasys

Korg Oasys sound workstation is real-time Linux based synthetiser with keyboard (it is just PC made to look like advanced workstation). It have multiple realistic synthetisers which can be combined in number of ways, allowing high degree of flexibility. All synthesis is done in software on the Pentium 4 CPU, and can be extended via software updates. Software in the Oasys is not avaible as separate product to use in PC. Theoretically it can be done, but legal issues and efort required to do this make this hard.

[edit] Manufacturers of Virtual Instruments and Software Synthesizers

Some of the most popular manufacturers/programmers include -

[edit] See also

[edit] References

  1. ^ "Microsoft Licenses Sound Canvas Sounds From Industry Leader Roland Corp". Microsoft Corp. 1996-10-22. http://www.microsoft.com/presspass/press/1996/oct96/rolandpr.mspx. Retrieved 2009-07-23. 
  2. ^ "Roland Corp. Licenses Sound Canvas Sounds and C Format for Apple's QuickTime 3.0". Apple Inc. 1997-12-18. http://www.thefreelibrary.com/Roland+Corp.+Licenses+Sound+Canvas+Sounds+and+C+Format+for+Apple's...-a020081812. Retrieved 2009-07-23. 
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