Caught between TDM, MAS, DirectX and VST? Tangled up in virtual inserts and aux sends? Never fear! Resident plug‑in guru Paul White is here to answer all your most common questions, and to help you get the most from software audio processing.
Plug‑ins are those pieces of software that add effects and signal processing functionality to audio applications such as multitrack recording software or MIDI + Audio sequencers. While these are often to be seen as the software counterparts of the traditional studio outboard units, such as compressors, equalisers, delays and reverbs, the extra flexibility of the software environment can make them more complex to deal with. So here I'm going to be tackling the most common of the many questions we receive here at Sound On Sound regarding their use.
There are some plug‑ins that function as virtual musical instruments, but they present entirely different challenges to the user and I won't be attempting to cover them here as well. However, keep your eyes peeled for a forthcoming FAQ devoted entirely to them.
Native plug‑ins are designed to work by using the processor within the host computer. Common examples are those in the popular VST (Steinberg's Virtual Studio Technology), MAS (MOTU Audio System) and DirectX formats, with numerous native plug‑ins available for both Mac and PC platforms. Because the same CPU that runs your native plug‑ins also has to run your audio recording and MIDI sequencing, the available processing power has to be shared between all these activities.
If a large amount of audio processing is being used in real time, it may be impossible for a single computer processor to cope with the calculation speeds required — one processor sometimes isn't enough! For this reason, some manufacturers have developed audio processing hardware for handling processing‑intensive audio functions, such as the running of plug‑ins. These are usually based around a PCI card on which are a number of specialised high‑power Digital Signal Processors (DSP). Because there are many types of DSP chip and operating system, the plug‑ins designed for use with such audio processing hardware will normally only work in conjunction with that specific platform. For example, Digidesign, Creamware and Soundscape all have their own proprietary plug‑in formats, each of which work only with their respective hardware.
Though programs such as Logic Audio and Cubase VST come bundled with a number of useful plug‑ins, many users of MIDI + Audio sequencers working to a budget find the cost of investing in plug‑ins difficult to manage, and as a result there is a considerable demand for freeware and shareware in this area. Free plug‑ins can be obtained two ways — legally and illegally. The illegal way is no secret, with pirate sites on the Internet offering cracked versions of many plug‑ins for download — however, increased vigilance on the behalf of the software manufacturers has succeeded in reducing the number of such sites.
Be warned that not only is the download and use of cracked software illegal, but it can also put the health of your computer music system at risk. For a start, many cracked plug‑ins are buggy and can therefore compromise the reliability of your sequencing package. Moreover, some people have found that trying to use an illegal version of one plug‑in alongside a legitimately purchased plug‑in can cause the key install disk of the latter to be rendered unusable. The bottom line is that if you steal software rather than buying it then nobody is going to bother to develop any more cool stuff, so don't do it!
Fortunately, the Internet also provides legal ways to download and use free plug‑ins. As Martin Walker found in Net Notes in SOS June 2000, it is far from difficult to locate legitimate freeware and shareware plug‑ins on the web — many have been written by enthusiasts just for the fun of it! Some of these plug‑ins are very good, others less so, and of course there's again no guarantee that they won't mess up your system (or even bring viruses aboard!) so be very careful when dealing with this type of product. Some of the better ones ask for a small registration fee, in order to fund the further development of their software. If you like something, paying out a few pounds to show your appreciation is a nice gesture and could also improve the feature set — the programmer is only an email away and they will sometimes even 'do requests', programming any specific extra features that you want into future versions of the software.
Plug‑ins vary as to how much processor power they demand. As a general rule of thumb, good‑quality reverbs tend to be the most hungry in terms of processing resources. Anything which offers physically modelled effects can also be quite processing intensive. Simple delays take much less processing power (though they need a little RAM to provide delay memory) while things like compressors, EQ and chorus effects usually come somewhere in the middle. Fortunately, most audio programs now have a CPU activity meter that will tell you how much processing power is being used and how much you still have in hand, so that you can allocate the resources you have in the most sensible manner.
The number of plug‑ins you can use at any one time depends on a number of factors. Proprietary plug‑ins that run on external hardware DSP will often limit the number of plug‑ins according to the number of extra DSP chips available. In this case, you might need to invest in upgrading this hardware is you can't get access to enough audio processing for your requirements.
Obviously, if you're running native plug‑ins then the more powerful the computer, the more plug‑ins it will be able to run. However, because different plug‑ins use different amounts of processing power, the number available will vary according to how power‑hungry each is. What's more, your CPU will also be having to handle sequencing‑duties and the recording and playback of audio tracks, so it's always a bit of a balancing act — the more playback tracks you have going at once, the fewer plug‑ins you are likely to be able to run. Having said this, a fast, modern computer should be able to run well over 16 tracks of audio along with rather more plug‑in effects than you'd probably use if you were working in a hardware studio. One word of advice, though, to those trying to squeeze the most out of their music systems: computers never work at their best if the CPU activity meter is banging against the end stops — all sorts of audio and MIDI glitches can occur unless you leave a little power in hand.
Q. How can I use plug‑ins which come with a key disk or dongle for authorisation if I have one of the new USB Macs which has no floppy drive or Adb port?
For any plug‑ins that require a key disk, you'll need to get hold of an external USB floppy drive. You will also need to download a software enabler from the www.paceap.com web site, as this will allow the USB drive to handle the Pace copy‑protection system which many plug‑in manufacturers use. ADB dongles (such as those used by Waves) can be used in conjunction with an iMate USB‑to‑ADB adapter, which costs around £60.
Many plug‑ins are platform‑specific and can therefore only be used with the system for which they were designed — for example, plug‑ins in MOTU's proprietary MAS‑format can only be used with their Digital Performer MIDI + Audio sequencing package. However, there are also a number of cross‑platform plug‑in formats, such as Premier, DirectX and VST, that are supported by a larger number of different audio programs — sometimes you'll even find that the same disk can be used to install a plug‑in on both PCs and Macs! Your software manual will tell you which plug‑in types your system can run.
Even if your current and prospective software sequencing packages both support the same plug‑in formats, it still doesn't necessarily mean that you'll be able to use all your existing plug‑ins when you make the move from one to the other. Even though you might be able to reuse your existing third‑party plug‑ins, any plug‑ins which have been built into your current sequencing software will not be accessible from within a different package. For example, the most recent versions of both Cubase VST and Logic Audio, both include proprietary built‑in effects that aren't available within other sequencing environments, despite the fact that they both support the VST format.
In my own experience, the low‑power reverb plug‑ins that come bundled with audio software compare pretty poorly with even modest hardware units, while the better‑sounding ones tend to be expensive as well as using a lot of processing resources. As a result, you may be better off using a hardware reverb rather than a plug‑in, as long as your soundcard allows you to configure some of its inputs and outputs as sends and returns. If you have to use a reverb plug‑in, then use the best that you can without overloading your CPU (or your pocket!) as good reverb is vital to most forms of music production.
When it comes to delays and modulation effects, however, the story is very different. Even fairly modest plug‑ins can often produce excellent results, so try out all the freebie plug‑ins that come with your system before looking to buy more expensive hardware or software — you could be pleasantly surprised at their quality.
Most programs allow you to cascade plug‑ins that are used in insert points, but the creation of chains of plug‑ins to be fed from an aux send is handled differently within the different sequencing environments. Routing and configuration details such as this are usually explained within the user manual. Cubase, for example, uses a virtual effects rack for effects loops, which limits you to one effect per send — frustrating if you want to apply EQ to a reverb plug‑in.
Fortunately there is a handy workaround for Mac‑based users of VST plug‑ins, using the TC Works Spark stereo editing program. Spark enables you to set up a 4 x 5 matrix of up to 20 VST plug‑ins at once, and to save this as a kind of macro which can then be used in any other VST‑compatible program as though it were a single plug‑in. What's more, these macros can even be made to operate as a single MAS plug‑in within MOTU's Performer. Obviously, you need to buy Spark, which is currently only available for the Mac, for this to work, but as it's such a useful editor (and comes bundled with so many good‑quality plug‑ins) it's well worth considering.
As a rule, you can play a live input via a plug‑in effect providing that your system's latency is low enough for doing this to make sense. However, you can't always record via a plug‑in. Once again, you'll have to check your sequencer manual for full details, as some software has not supported live inputs until recently — for example, Logic Audio has only supported them since version 4.5.
Q. Can different types of plug‑in format be used at the same time. For example, can TDM plug‑ins be used at the same time as VST plug‑ins?
A TDM system uses external DSP hardware which can't run VST plug‑ins and a native system can't run TDM plug‑ins. However, some software will allow you to access both native and hardware processors at the same time (as long as the appropriate hardware is installed). For example, if you have a Pro Tools system connected to a Mac, but you also have an Emagic's Audiowerk8 card installed, it is possible to set some tracks up for DAE (Digidesign Audio Engine) support and some for AW (Audiowerk). This allows you to use different plug‑in standards within the same project, though you still won't be able to use them simultaneously within the same track.
Some programs allow plug‑ins of one type to masquerade as another type, effectively letting you use different types together. In addition to TC Works Spark, which lets you use VST plug‑ins within MAS‑compatible applications, there is also Angus Hewlett's VST‑DX Wrapper, which transforms VST plug‑ins to work within DirectX‑compatible software — this can be downloaded by surfing to www.fxpansion.com.
Not all of the plug‑in formats allow for plug‑ins to accept MIDI tempo information from their host application — the VST 2 format does. However, even if a plug‑in format is designed to allow plug‑ins to be locked to tempo, not all sequencing software sends the necessary tempo information. For example, Emagic's Logic Audio can sync its own built‑in plug‑ins to MIDI tempo (for tempo‑related delays and so forth), but not VST 2 plug‑ins and virtual instruments, even though their plug‑in format is capable of tempo sync.