Recognizing the Role of Plug-Ins in Your PC Recording Studio - dummies

Recognizing the Role of Plug-Ins in Your PC Recording Studio

By Jeff Strong

Plug-ins are an important part of your computer-based recording system and one of the features that sets it apart from your old tape deck. Plug-ins allow you to process the sound of your instrument in an almost unlimited variety of ways. These can range from basic effects — stuff such as reverb or delay — to tricks such as raising the overall volume of your track (called normalizing your track) or changing the pitch of an instrument.

By using plug-ins, you can process your tracks in one of two ways:

  • Real time: Real-time processing means that your audio is processed as your song plays. This approach puts a load on your computer, so the number of plug-ins you can run at one time depends on how powerful your computer is. This is the approach you use when you actually mix songs and you want to add effects to your tracks.
  • Offline: Using plug-ins offline means you process the audio when your song isn’t playing; you end up with a new audio file that includes your newly processed audio. This is common for some usual processing chores, such as normalizing, quantizing, transposing, and other new-fangled audio processing approaches. The ways you can process your audio offline depend on your audio recording program and the plug-ins you have loaded into your system.

Some audio recording programs, such as Apple’s Logic, have a freeze function that lets you apply your effect plug-ins (reverb, compression, and others) in a manner similar to that of the offline approach. The difference is that you can unfreeze your track, adjust your effect parameters, and freeze it again. This offers the advantage of leaving your processor unburdened by the weight of your effect as your song plays, thus allowing you to run more plug-ins in your song without having to get a faster computer.

Figuring out formats

Plug-ins come in many formats but follow only two different processing approaches. These facets of plug-ins are covered in this section.

When audio recording software programs were first developed, they each used their own formats for their plug-ins. Because originally no plug-ins were made by third-party manufacturers, this wasn’t a problem. As recording programs became popular, third-party plug-ins starting becoming available, and these third-party makers needed to make some decisions — including which format to develop their programs in. (Figuring out a catchy name for marketing purposes was also high on their To-Do lists.)

The more popular plug-in formats are

  • Audio Units: Audio Units (AU) is a format developed by Apple for OS X. This format is just beginning to gain a wider share of available third-party plug-ins; it’s used in programs that run on Mac OS X, such as Logic and Digital Performer.
  • Direct X: Direct X (DX) is a format developed by Microsoft for Windows systems (sorry Mac users, you can’t use these plug-ins) and is employed in programs such as SONAR and other Cakewalk products. The DX format is one of the most common plug-in formats.
  • MAS: The MAS format was developed by MOTU for Digital Performer. This plug-in format isn’t as common as many of the others, and Digital Performer now uses Audio Units in its program.
  • RTAS: Real Time Audio Suite is Digidesign’s proprietary plug-in format used on Pro Tools LE software (and sometimes Pro Tools TDM). Numerous RTAS plug-ins are available.
  • TDM: TDM plug-ins are Digidesign’s DSP-based plug-ins for the Pro Tools TDM system. (DSP stands for digital signal processing.) These plug-ins are host-based plug-ins, which means they run off of the DSP chips for Pro Tools instead of from the processor in your computer. This has a couple advantages:

• Your system isn’t stressed by these plug-ins. This is less of an issue now than it was, say, a couple years ago, because computer-processing power has improved a lot.

• The makers are insured against piracy. Because these plug-ins require a computer chip to run, they can’t be copied. This has resulted in some very high-end plug-ins being developed in this format.

    The problem is that you need a Pro Tools TDM system (which is expensive), and these plug-ins are much more expensive than their non-host-based counterparts.
  • VST: Developed by Steinberg (the maker of Cubase and Nuendo, among other programs), VST plug-ins are used on both Mac and Windows computers. This is by far the most popular plug-in format and as such you find lots and lots of options.

You can find special adapters known as wrappers that allow you to use one format of plug-in in a program that runs on another format. For instance, many people who used Logic or Digital Performer before OS X (myself included) collected a huge array of VST or MAS plug-ins for their work. When making the switch to OS X, these plug-ins suddenly became useless. That is until the fxpansion VST to AU wrapper was introduced. Now all you have to do is install the wrapper and you can run your VST plug-ins in a program that requires an AU plug-in. This relatively inexpensive option saved many people from having to throw away their old plug-in collections.

Peeking into processing approaches

Plug-ins come in two varieties: those that run off your computer’s processor (native) and those that have their own DSP chip to run from (host-based).

Native plug-ins

Native plug-ins are those plug-ins included in your audio recording program and those that you get when you download or buy them as software. Native plug-ins run off the processing power of your main computer. This used to limit both the quality of the plug-in and the number of plug-ins you could run at one time. Because computers are getting more powerful, this isn’t much of limitation anymore.

Host-based plug-ins

Host-based plug-ins are plug-ins that run off a dedicated processor. Until recently, unless you had a Pro Tools TDM system you couldn’t take advantage of plug-ins that ran on their own processor chips. Now, with the help of some savvy third-party manufacturers, no matter what types of audio recording software you use, you can use plug-ins that don’t put stress on your computer. Currently, two options are available:

  • TC Powercore: The TC Powercore is available as a PCI card that you put into one of the PCI slots in your computer or as a FireWire unit that you plug in to a FireWire port in your computer. (The latter approach lets you use the Powercore with a laptop.) This unit has lots of good plug-ins. The reverbs stand out as some of the best available. Visit TC Powercore to find out more.
  • Universal Audio UAD 1: The UAD 1 is available only as a PCI card at this time, so this option can’t be used unless you have a free PCI slot in your computer. The UAD 1 is known for having some dynamite dynamics processors, including a great limiter and compressor. Check out for more information.

Host-based plug-ins are always sold with some sort of processor chip and can’t be used without the host processor. These plug-ins often sound very good, but you pay more for them because you’re buying hardware as well as software. After you have the hardware in place, though, you can often buy more plug-ins to run on your host’s processor, making this option expandable.