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MIDI, Audio & PC Plug-ins

Exploration By Martin Walker
Published March 1998

It's amazing how many effects can be crammed into a DMSS‑compatible application like Cubase VST. Up to four different effects can be used for input channels, and four more as Master effects.It's amazing how many effects can be crammed into a DMSS‑compatible application like Cubase VST. Up to four different effects can be used for input channels, and four more as Master effects.

There are now several PC MIDI + Audio sequencers available that provide real‑time EQ and effects via plug‑in software — but it can be difficult to assess just what works with what, and whether your PC is powerful enough to run the plug‑ins you'd like to use. Martin Walker investigates.

Many musicians are now using the latest versions of the big three MIDI + Audio sequencers for the PC (Cakewalk Music Systems Cakewalk Pro Audio, Steinberg Cubase VST and Emagic Logic Audio), but there remains a lot of confusion as to what hardware each supports and just how much PC power is needed to run typical setups with plug‑ins in real time. When you try to run a sequence containing both MIDI and audio, using real‑time effect plug‑ins, your PC is being called on to do an awful lot at once. Not everything is compatible with everything else, and if you attempt to add some of the more esoteric mastering plug‑ins (enhancers and high‑end reverbs in particular) you may find that your music judders to an intermittent halt. In addition, new soundcards are being released every month, and though some specifically support one or more of the major sequencers, others promise future support, and some combinations are unlikely to ever see the light of day, due to various political machinations.

With all this going on, it's no wonder that many people are cautious about investing in plug‑ins, especially as they can often cost more than the sequencer they support. Fortunately, third‑party developers have already spotted the gap in the market for audio plug‑ins that sound good but don't hog all of the computer's power (I've managed to get hold of a couple of the new ones for review here), so let's look at the current situation to see just what works with what, and what sort of PC you need to do it.

Hardware Support

The new‑look Logic Audio 3.0, showing the mixer and Mono In/Stereo Out Reverb page.The new‑look Logic Audio 3.0, showing the mixer and Mono In/Stereo Out Reverb page.

At the time of writing, Cubase VST for Windows is at version 3.502, Cakewalk Pro Audio stands at 6.01, and Emagic have just released a major update to Logic Audio 3.0.6, which brings it more into line with the real‑time effect possibilities of its rivals. All three can run with any soundcard that provides standard Windows 95 Multimedia drivers, but this can sometimes result in limitations, as we shall see later. The ideal solution is to use drivers that interface directly between a specific sequencer and a specific soundcard, so that the code can be streamlined. Here we get into murkier waters, and although much progress is being made behind the scenes, it's not advisable to buy an exotic soundcard unless the appropriate driver is already available.

Normally, it seems to be up to the soundcard manufacturer to write these application‑specific drivers, using information made available by the sequencer manufacturer. However, when certain manufacturers make both soundcards and sequencers, there may be a conflict of interest. A classic case is Emagic, whose Audiowerk 8 card has a great spec, and would seem ideal for partnering with any multi‑channel application. However, although Logic drivers were made available for this card very quickly, drivers to allow the Audiowerk 8 to be completely integrated with Cubase and Cakewalk have been very slow in arriving. Only a Beta‑version Multimedia driver is available even now, and this only lets you use a single stereo in/out (and S/PDIF I/O) from the card's eight hardware outputs. Musicians who already use Logic are obviously more inclined to buy an Audiowerk 8 card, but I doubt that long‑term Cubase or Cakewalk users are likely to swap to Logic Audio just so that they can use the Audiowerk 8 card. The availability of drivers has become an important issue.

The Big Three

The Sonic Foundry Multi‑Tap Delay (one of the range of six plug‑ins provided with the XFX 1 pack) is capable of providing a huge range of delay cluster effects.The Sonic Foundry Multi‑Tap Delay (one of the range of six plug‑ins provided with the XFX 1 pack) is capable of providing a huge range of delay cluster effects.

The PC version of Cubase VST 3.5 was shipped with Multimedia ASIO (Audio Stream Input and Output) drivers. These allow any soundcard which has Windows 95 drivers to be used with it; most multi‑channel cards using Windows 95 drivers (apart from Audiowerk 8) appear to Windows 95 as a number of stereo pairs, each with a different driver entry. This allows you to access any of the multiple inputs and outputs available. On the PC, card‑specific ASIO support is rather slower off the mark, although apparently good progress has been made with the Korg 1212 and the Event Darla and Gina drivers (currently at the initial Alpha stage); Digidesign are also developing an Audiomedia III card driver for VST. A file called 'Troubleshooting.txt' on the VST CD‑ROM indicates the best settings for a wide variety of soundcards using the Multimedia ASIO driver, including the Creative Labs AWE series, DAL CardD+, Event Gina and Darla, Hohner‑Midia Arc 44, Terratec EWS64 XL, and Turtle Beach Fiji and Pinnacle. More specialised hardware, such as the Akai DR8/DR16, Yamaha CBX‑D5 and Digidesign Session 8 (previously catered for by Cubase XT) is no longer supported, as integrated EQ and effects cannot be provided when simply remotely controlling other hardware.

Cakewalk Pro Audio 6.01 allows various specific hardware options. Apart from, again, supporting all soundcards which have standard Windows 95 Multimedia drivers, it also directly supports the Digidesign Session 8 and Audiomedia III cards and Digidesign's EQ plug‑ins, although these can only be used as inserts, and not via effects loops. DAL's V8 system (and the V8 custom plug‑ins, which include a special version of Waves' Native Power Pack) is also supported, and in this case the effects can be used as either single‑channel inserts, or in the aux send/return system. Finally, Soundscape's SSHDR1 is supported at the recording/playback level, although none of its internal effects can currently be accessed.

The most recent package of the three I'm talking about is Logic Audio 3.0, which has only been shipping for a few weeks. It supports Multimedia cards in the same way as the other two, but also has specific support for the Digidesign Audiomedia III, Audiowerk 8 (of course), and Soundscape's SSHDR1, subject to similar limitations as the other sequencers. Logic is a special case — not only are the real‑time plug‑ins supplied with the sequencer proprietary (like the in‑built VST ones), but there is also currently no way to add DirectX plug‑ins at all. Since DirectX seems to be the emerging standard, I asked Emagic what their future plans were. Their response was: "In the very near future Emagic will release new versions of its Logic Audio system that will include support for other plug‑in formats". That sounds to me as if DirectX is on the cards. Keep your fingers crossed.

...it's not advisable to buy an exotic soundcard unless the appropriate driver is already available... and it's up to the soundcard manufacturer to write these...

Bundled Effects

TC Works' Native Reverb sounds as good as it looks, and the user interface is very responsive, allowing you to get the exact sound you want with a minimum of fuss.TC Works' Native Reverb sounds as good as it looks, and the user interface is very responsive, allowing you to get the exact sound you want with a minimum of fuss.

With all three packages, a selection of bundled effects is provided. To give you an idea of their scope and the power on offer, I listened to all of them, as well as measuring (as far as possible) the typical processor overhead running in Cubase VST. This figure gives you an idea of what proportion of your overall power is being used. I used a PC fitted with a Pentium 166MHz MMX processor, but to calculate the equivalent overhead used by a different speed of processor, you simply multiply or divide accordingly (for example, if the result is 5% for the 166MHz processor, a 200MHz processor would take 166/200 as much, or about 4%).

Interestingly, the VST effect overhead appears when you click on the VST Effects Power switches, and doesn't increase significantly when further channels are added to the effects mix buss — the effect takes far more processor power than simply mixing the audio at its input. For this reason, if you're running close to the limit it's worth remembering that using a different amount of reverb send on every channel, to the same reverb plug‑in, will take a lot less overhead than attempting to run several different ones, each patched to a different channel.

Cubase VST is supplied with six Mixer Effects (Mono in/Stereo out). Not surprisingly, the AutoPan requires least power (3%), since it is only moving audio between the speakers, rather than modifying the actual waveforms. StereoEcho only takes 3.5%, for similar reasons; FuzzBox takes 4%; Wunderverb 3 is a basic reverb with three controls (Size, Decay and Damp) which works surprisingly well considering that it only needs 6% of the processor's power. It can provide some wonderful metallic tube effects and some reasonable room reverb sounds, but tends to always have a metallic edge to its decay, which makes it difficult to recommend as a main reverb. Both Espacial (ambience and room FX) and Choirus (Chorus and Flanger) take 8%. Espacial provides more early‑reflection controls than Wunderverb, but still sounds metallic. It's advisable to turn the speaker levels down a bit when fiddling with both Wunderverb and Espacial parameters, since it is possible to come up with settings that cause loud 'cracks' and break‑up.

Overall, the Cubase VST bundled effects are extremely useful, and my comments on the two reverbs should be taken bearing in mind that the excellent Waves' Trueverb needs a mammoth 72% of processor power measured in the same way. Of the two, Wunderverb 3 can sound surprisingly good with many sources; it's only when it's called on to act as a vocal or drum reverb that the limitations become obvious — something you could also say of many budget hardware effect units.

Cakewalk Pro Audio 6 comes with bundled DMSS effects (including 2‑band EQ), and once again I used Cubase VST as a comparative engine to test these. The CFX 2‑band EQ is the only one that you can use in real‑time with Cakewalk Pro Audio 6 — you can process audio with more advanced options, such as parametric EQ, but only off‑line. The CFX Delay/Echo takes 6%, and provides a wide variety of treatments. The CFX Reverb takes 17%, but despite the fact that it has more than double the overhead of either of the Cubase reverbs (partly due, no doubt, to the fact that it is DMSS compatible, rather than tied uniquely to its own program), the sound quality isn't significantly better. Switchable early‑reflection settings are provided (None, Sparse or Dense), as well as a high‑pass and low‑pass filter, and its basic character is clean, but the ends of the reverb tails are very lumpy. The Chorus and Flanger effects are good, though. So, overall, Cakewalk owners have a good range of effects to get them started.

Unfortunately, Logic Audio 3.0 finally arrived just a day before this feature was finished, so only a very brief audition was possible, but SOS has reviewed the equivalent Mac version in full (see the January 1998 issue), and there will be a separate look at this PC version soon. In the short time I had to listen to the built‑in effects, my favourite was the Reverb: with eight tweakable parameters, including Room Size, Decay, Density, High‑Frequency Damping, and Pre Delay, this provides a wide range of sounds, although there always seems to be a slightly metallic edge at the end of longer decays. The Quality option offers four settings, from lumpy to smooth, and allows you to decide on the balance between quality and processor overhead. At the highest setting, the Logic reverb gives a much smoother sound than either the Cubase or Cakewalk reverbs, but it does seem to take about 40% overhead. However, the final reverb parameter is Region Gate, and this is a clever way to minimise that processor overhead — you can set a time between 0 and 25 seconds beyond the audio region, after which the effect is completely cut, so that it takes no further overhead until you need it again. Setting it slightly longer than the reverb decay ensures that the effect is switched off when no sounds are present.

Sonic Foundry XFX 1 Plug‑Ins

The Sony DPS V77 is just one of a number of effects processors that provide full digital I/O, so that you can preserve your digital path when adding external effects.The Sony DPS V77 is just one of a number of effects processors that provide full digital I/O, so that you can preserve your digital path when adding external effects.

Although quite a few plug‑in packs are available for mastering purposes (de‑clicking, spectral enhancement, noise reduction), many people will be looking for additional general‑purpose ones to swell their effects arsenal. One of the first manufacturers off the blocks is Sonic Foundry, with the XFX 1 pack. This consists of enhanced real‑time versions of a group of effects that were only previously available within the Sound Forge software. Because they have been re‑jigged to be DirectX compatible, they can now be used inside Cubase VST or Cakewalk Pro Audio, as well as with Wavelab and Sound Forge itself.

The Simple Delay provides echoes from 1ms to 5 seconds, and has feedback and decay controls for slapback, follow‑on echoes, and resonant tails. The MultiTap Delay gives you between one and eight taps, each of which can be set between 1ms and 2.5 seconds, plus parameters for global modulation rate, depth, and feedback, with an adjustable low‑pass filter. There's also a graph showing the delays, which makes life a lot easier, and it's possible to set up complex treatments fairly quickly.

DirectX seems to be the emerging standard...

The Chorus effect provides initial delay, mod rate, depth and feedback, a low‑pass filter and feedback, and options to invert the chorus or feedback phase. The chorus size can also be adjusted from one to three stages, which determines the number of times the signal is processed through the chorus algorithm. Although you can get some richer sounds from this than you can from the built‑in Choirus plug‑in already included with Cubase VST, no stereo spreading is provided (a mono channel in seems to result in a mono channel out), so the overall effect is somewhat diminished compared to Choirus.

The Reverb provides a wide range of settings, with 19 modes ranging from subtle ambiences, through a variety of rooms, halls and a cathedral, to more off‑the‑wall spaces such as corridors and metal tanks. There are 10 early reflection styles, plus controls for pre‑delay and decay time, and fully adjustable high‑ and low‑pass filters. A wide range of sounds is available, but they do sound a bit lumpy and grainy with more critical sources such as drums and vocals. Also, strangely, although the early reflections are capable of being spread really wide, the distant reverb is always fairly narrow — suitable for adding effects, but not as good for wrapping an acoustic around a mix.

The final two plug‑ins provided in this package are Pitch‑Shift and Time Compress/Expand. Both of these provide useful effects, but shifted audio suffers, as audio does with most similar algorithms, when moved a long way from its original pitch or speed.

One small disappointment is that the large selection of presets that appear when these plug‑ins are run from Sound Forge does not seem available from within any other package (this was also the case with Waves' Native Power Pack until the latest update). Sonic Foundry say that this will be fixed in a free update likely to become available in January.

Taken as a batch of plug‑ins, the XFX 1 pack is good value. The most useful individual plug‑ins are the MultiTap Delay and the Reverb. The latter is significantly better than the built‑in ones within Cubase, but it still isn't really of high enough quality to use as a main reverb for drums and vocals.

The next pack in the series (XFX 2) is due to be released early in 1998, and again features plug‑ins previously only available within Sound Forge. These will include Noise Gate, Graphic Dynamics, Multi‑Band Dynamics, Paragraphic EQ, Parametric EQ, and Graphic EQ.

TC Works TC Native Reverb

The TC Native Reverb is the first in a new series of plug‑ins from TC Works, a new company formed by TC Electronics which will concentrate on computer‑based audio workstations, on both Mac and PC platforms. TC Electronics already have an enviable reputation for their DSP technology, used in products such as the Finaliser (reviewed in December 1996), and the M2000 digital effects processor (reviewed in August 1996). All this augurs well for their first reverb plug‑in; you can download a free demo (with every control locked to a single preset value) direct from the TC Works website if you want to see for yourself. TC Works distribution is being handled in the UK by Arbiter Pro Audio, who also handle the Steinberg range.

Installation is simple, but one departure from the norm is that if Cubase VST is detected on your PC, two extra versions of the plug‑in are installed for VST channel and master duties, as well as the more general DirectX one (the VST channel version doesn't need a mix control, and so takes slightly less processor overhead).

My initial impressions were good: the TC Native Reverb has a very smart graphical interface, which presents every parameter in a single, easy‑to‑use window. There are two meters, indicating Reverb send level (adjusted by an 'In' slider), and combined Direct/Reverb output level (adjusted by an 'Out' slider). There's also a third slider, labelled 'Mix', which adjusts between full dry (0%) and full wet (100%) mix (this is blanked out in the VST channel version). The other half of the window hosts an extremely clever interface which, although being easy to use, provides a huge range of control options.

The display window shows the settings of the current 'ROM' preset (10 available), Decay Time (from 0.1 to 20 seconds), and Room Size (nine settings, ranging from Box, through Medium, to Huge, and including a Spring setting, which alters the scaling of the early reflection patterns). You can select each of these by clicking on the appropriate switch, and once a switch has been selected, you use the large Value dial alongside to alter its value, by clicking on its pointer and dragging the mouse up or down. I found this a bit fiddly, and there seems to be no reason why the whole dial should not be 'active' for initial grabbing, rather than the much smaller pointer. It's actually far easier to left‑ or right‑click within the display window to increment or decrement values.

There are four more graphic controls beneath the Display.

  • Shape (Square, Curved, or Round) affects the early reflection patterns. Most of the presets use the Square shape, but the Cathedral uses the Round one, and both the Church and the Tiny Box use Curved.
  • Diffuse affects the level of 'liveliness' of the walls of the virtual room, by adjusting the density of reflections in the reverb decay.
  • Color is a two‑way control which seems to control high‑frequency damping and EQ from top to bottom, and low‑frequency damping and EQ from left to right.
  • Pre‑Delay shifts the reverb timing relative to the direct signal, and this is proportionally linked to the Room Size button, so that whatever pre‑delay you select will be scaled up and down according to the chosen room size.

Soundwise, the TC Native Reverb certainly lives up to expectations, and the 10 presets offer a wide range of room types. Reverb tails are extremely smooth, wide and deep, and have no obvious coloration as they decay (unless you use extreme settings, such as tiny rooms or boxes, where ringing is intentional). The Color control provides a huge range of treatments, from rich and warm right through to cold and spiky.

If you directly compared the TC Native Reverb screen display to the busier one of the Waves Trueverb, you might initially expect that the TC plug‑in would provide less scope for editing. However, each control of the Native Reverb does a lot, which makes it easy to quickly achieve the sound you want. Even using a Pentium 166 MMX, the Native Reverb only takes 44% processor overhead, due to well‑optimised algorithms (TC Works recommend a minimum of a Pentium 133MHz, and for once I can believe it). The only drawback of this plug‑in is its retail price of £329, which is as much as any of the sequencers that run it.

Plugging Into The Future

Reverb is the one effect that almost every mix needs, and you do need at least one good one for more professional work. With a 166MHz processor, Waves' Trueverb could scrape through with 72% processor power, although once you have eight or more audio tracks playing back, as well as MIDI ones, you could be close to the glitching limit — TC's Native Reverb is much easier to use in this respect, if you can afford it. To give you some idea of normal overhead, the demo on the VST CD‑ROM (six mono audio tracks, plus two MIDI tracks, four low‑overhead channel effects on, and two Master effects) took a maximum of 30% overall, which is pretty good going. Having mentioned Trueverb yet again, I should also mention that the Waves Native Power Pack (reviewed in the June 1997 SOS) has recently had a price reduction to £399, and for a half‑dozen top‑notch effects this is even more of a bargain.

Waves' AudioTrack (an all‑in‑one plug‑in which includes EQ, compression, gating, and expansion) is still being sold by Arbiter Pro Audio at a special price of £69, and hundreds have been sold since Cubase VST came out. Another new plug‑in due from Arbiter Pro Audio early in 1998 is a software version of the Waldorf filter, for beefing up synth sounds. Full MIDI control will allow filter sweeps to be incorporated into a VST sequence.

Many Mac developers are now in the process of porting their wares across to the PC. Prosoniq have announced that demos of all their plug‑ins (including the VoxCiter and Roomulator) will be available in January, and the full versions by February. Traditionally, Mac plug‑ins have been intended for high‑end DSP farm use, with prices to match, but native versions (using only the PC processor) seem to be the norm for the PC, and prices are dropping accordingly. Even Waves have got in on the act, having just announced the EasyWaves pack, which consists of AudioTrack (mentioned above) and EZVerb, a reverb with presets taken straight from Trueverb. At a price of £125, this looks likely to sell and sell.

It seems that there are still a few compatibility issues, though, and no doubt by the time you read this others will have surfaced or been sorted. One of the minor annoyances is that many plug‑ins are supplied with libraries of presets that only appear within certain host applications (as with the XFX 1 pack mentioned earlier) but developers are generally sorting these bugs out fairly rapidly and making free updates available via their websites — I'll report on these in SOS's PC Notes column.

With MIDI + Audio sequencers becoming more and more popular, and prices falling for the latest high‑quality soundcards, the stand‑alone computer studio is becoming an increasingly affordable prospect for many people, and without significantly compromised audio quality. The PC musician is no longer the poor relation in audio.

External Effects

If you're running a computer‑based studio with the bulk of the EQ and effects happening totally within the digital domain, any hardware help that can be provided will greatly ease the burden on the PC's main processor. Most soundcards provide onboard DSP power (although only a few use this for high‑quality effects), but another option for soundcard owners is to add an external effects unit via the soundcard's digital I/O sockets. Even with a single stereo digital channel, you could configure this as two mono sends and a single stereo return. Since many modern effects units provide a selection of algorithms that use that very configuration, this would seem to be an ideal way to add quality effects. The fly in the ointment is that few effects processors in the affordable category come with built‑in digital I/O, although I suspect that this will start to change as more people move towards all‑digital setups. Units that do provide digital I/O as standard include the Alesis Quadraverb 2 (reviewed SOS October 1994) and the Sony DPS V77 (reviewed SOS September 1996). Others, such as the Digitech Studio 400 (reviewed SOS October 1996) and Lexicon PCM90 (reviewed SOS May 1996), offer digital I/O as expansion options.

Directx Plug‑In Overheads

To give you an idea of how many plug‑ins you're likely to be able to use, I did some testing. First, I ran a single channel of audio in Cubase VST 3.502. Having measured the percentage of total processor power used (overhead) when running this channel with no effects at all, I then systematically added effects, and measured the increase shown in the Cubase VST Performance CPU meter (achieving more accurate figures by averaging the result of running several simultaneously). The figures below were arrived at using a Pentium 166 MMX and show the extra overhead taken by each effect (after subtracting the proportion taken by the audio playback alone). Remember that this overhead is for switching on the effect — multiple channels can access a single reverb, seemingly without significantly affecting overhead. In the case of effects whose overhead varies depending on how you set it up, results are for the default settings.

PLUG‑IN:OVERHEAD

CMS CAKEWALK

Time‑Stretch/Pitch Shift4%
Chorus5.5%
Delay/Echo6%
Flanger 6.5%
2‑band EQ8%
Reverb17%

QTOOLS

QSys/AX (wide panner)8%
QXpander* (width expander)11%
Q123/AX (mono to 3D)18.5%

SONIC FOUNDRY XFX 1

Simple Delay6.5%
Multi‑tap Delay14%
Chorus (3‑stage)29%
Reverb31%
Pitch‑Shift35%
Time Compress/Expand16%

STEINBERG CUBASE VST

Built‑in EQ less than 2%
AutoPan3%
StereoEcho3.5%
FuzzBox4%
Wunderverb 36%
Espacial!8%
Choirus8%
Grungeliser22%
Spectraliser*80%

TC WORKS

Native Reverb44%
Native Reverb VST42%

WAVES

S1 Stereo Imager*10%
C1 Gate10.5%
C1 Compressor15%
L1 Ultramaximiser*20%
Q10 Parametric EQ30%
Trueverb72%

NB: The plug‑ins marked with a * were used as Master effects.

It's On The Cards

Hardware support is a major issue, since so many recent multi‑channel soundcards have on‑board DSP chips, with enough processing power to provide additional real‑time EQ and effects, to help the main CPU. It should be possible for any soundcard manufacturer to provide a stand‑alone utility to allow you to change EQ and effect settings for each channel of a particular soundcard. However, this seems to be a rare option, and often the only way to access any of these special features is via a purpose‑designed hard disk recording program. This may come bundled 'free' with the hardware, or it may be a separate purchase. However, to add support for MIDI you need to run a separate MIDI sequencer, with the added complication of syncing the two packages together (as well as swapping between the two screen displays on a regular basis).

The beauty of using hardware DSP is that your PC can run more tracks and extra plug‑ins, since a significant amount of the processing is being taken care of by the soundcard. For Cubase users, I suspect that a popular solution will be the forthcoming Lexicon Studio system (due in March 1988), which integrates Cubase VST with a multi‑channel PCI soundcard and a special version of the famous PCM90 reverb. Unfortunately, soundcard DSP is always proprietary, so different code will be needed to run plug‑ins on the DAL V8 card (reviewed in this issue), Ensoniq Paris (reviewed SOS January 1998), and so on — you can't run DMSS plug‑ins using the soundcard.

Even cheaper modern cards such as the Event Gina (reviewed in the December 1997 SOS) have sufficient DSP power to hold out the carrot that future driver updates should be able to allow plug‑ins to run directly using some of this DSP power, rather than the main computer processor. Indeed, the ultimate plan is to produce an ASIO driver that supports VST processing directly on the Gina's DSP.

Plug‑In Prices & Contacts

QSOUND

QTools/AX £199.

www.etcetera.co.uk

SONIC FOUNDRY

XFX 1 plug‑ins pack £199.

www.sfoundry.com

TC WORKS

TC Native Reverb £329.

www.tcworks.de

WAVES

EasyWaves £125; Native Power Pack £399.

www.waves.com