Emagic EXS24

Emagic's virtual sampler provides Logic Audio users with a practical alternative to hardware‑based sampling. Paul White puts it to the test.

Ever since sequencers became audio‑capable, I've been waiting for sampling to be included, because to my way of thinking it makes a lot of sense for both practical and technical reasons. For example, computers have loads of RAM for playing back samples, they have hard‑drive space to store your sample library, and they have inbuilt CD‑ROM drives for accessing sample libraries. They also provide on‑screen editing, and allow you to open up separate virtual samplers, each on their own sequencer track, to play the various parts, rather than making you mess around with obtuse multi modes.

Over the past couple of years, this dream has become a reality, with Bitheadz' Unity DS1 probably being the best known third‑party virtual sampler. Now Emagic have come up with their own solution specifically for Logic Audio users.

Getting Going

The editing view of EXS24 allows you to assign samples to MIDI notes in much the same way as within an Akai sampler program.

Unlike VST Instruments, Emagic's EXS24 isn't designed for use within other VST‑compatible sequencers — it's strictly for use within Logic Audio. On the one hand this looks like a case of cutting off the nasal orifice to spite the face, but on the other hand it does allow the designers to achieve very tight integration between the host program and the virtual instrument. At the time of review, only the Mac version was available, though PC support is anticipated later in the summer, and the following software drivers are available: Mac AV/PC AV, Audiowerk, EASI, Direct I/O, ASIO, StudI/O (Mac only), 1212 I/O (Mac only).

So, what does EXS24 expect of you, or more precisely, of your computer? Although the manual claims that the sampler is fairly economical on processing power, and so will perform reasonably well on older computers (Power PC 604 200MHz minimum), you'll need a G3 or G4 to get the best out of it, and the faster the computer, the lower the latency tends to be. On my 450MHz G4, the response is so fast that latency ceases to really be an issue, so it's much like playing a hardware sampler. Because the EXS24 uses some of your computer's RAM for playback, having at least 128Mb more than you previously needed might be a good idea. Having satisfied these requirements, multiple EXS24s can be used in up to 16 tracks at once permitting 16‑part multitimbrality. It's hard to put a figure on the maximum polyphony, but I had five tracks running along with a few MIDI tracks and the CPU meter showed less than 10 percent loading. If you do happen to run out of polyphony, sampler tracks can always be bounced down to disk.

Installing the software is simply a matter of inserting the CD‑ROM, hitting Install and agreeing with the various dialogue boxes that pop up from time to time, though if your version of Logic Audio is prior to v4.3, the installation will stop part way through and ask permission to update your software to the later version. Once the update is done, the installation continues. There are no dongles or key disks — you simply have to reinsert the install CD when asked, which doesn't seem to be too frequently. A small selection of useful samples is bundled with the software and there's a further disk that's sent to you when you register your purchase.

The Interface

All the Instruments in the Sampler Instruments folder are accessible within the sampler plug‑in via a pull‑down menu, and loading is stunningly fast — it's almost like selecting a new patch on a ROM‑based synth. My one complaint about this section of the program is that, although you can use your Mac's folder view options to select alphabetical or by‑date listing, there is no system for creating your own subsections such as pads, loops, basses and so on. A few users have already commented on this, so I wouldn't be at all surprised to see some improvement in this area before too long. As it is, the Instrument list can quickly become very long and unwieldy.

EXS24's controls are accessed via two windows, the first of which is opened by double‑clicking the instrument insert point in the Audio Instrument Object where the plug‑in is being used. This plug‑in window looks much like that of any virtual analogue synth, with separate envelope generators for filter and amplitude, a resonant filter, LFOs for modulation and so on. The filter has a choice of four modes from 12 to 24dB slopes (with Fat or Classic 24dB settings), along with resonance and distortion options, and it may also be switched off to economise on processing power. There is one polyphonic LFO and one monophonic LFO, each with a useful choice of waveforms, and these can be sync'ed to tempo if required. The envelopes are of a four‑stage ADSR type and voices may be played in poly, mono or legato mode.

The only major difference between EXS24 and a virtual synth, in fact, is that instead of an audio oscillator you choose a sampler 'Instrument' from your library to provide the source waveform. As I mentioned earlier, this Instrument is pretty much equivalent to an Akai Program and includes the 'front‑panel' control settings, the keyboard mapping and any splits or layers you might have set up, as well as things such as sample tuning, loop points and crossfade duration.

The second window is called up by clicking the Edit button just above and to the left of the filter panel. This brings up a screen with a keyboard across the top and bars beneath it representing the various Zones used, along with their key ranges. Each Zone has an associated dialogue box where the sample start, end and loop point can be changed and where the sample may be tuned. A velocity range can also be added to provide velocity‑related sample switching. You can assign any Zone to be part of a Group — useful for drum samples if you decide to put all your kick drums in one group, all the snares in another and so on. This makes it easier to handle level changes or other parameter adjustments as you can opt to treat the entire group in one action. Groups may then have their number of voices specified, from 1 to 24, and it's possible to enter envelope, resonance and filter cutoff frequency offsets. The triggering mode is set at Zone level and can be conventional, one‑shot or reverse, so setting up a hi‑hat mode is no problem. Panning may also be carried out at Zone level in addition to level trimming.

Sampling

Technically, EXS24 is more of a sample‑playback program than a sampler, but that's only because Logic Audio already has most of the tools to do that part of the job. If you have another piece of audio software that suits you better, you can also use that to record and edit raw samples. To create a sample, it's necessary only to record a sound into Logic, then trim it in the Sample edit window. It may then be loaded directly into a Zone for use just as it is, though you can use any of Logic Audio's audio processing tools to treat the audio first — EXS24 can support any file format used by Logic Audio (AIFF, WAV and SDII mono or stereo files) right up to 24‑bit/96kHz if necessary.

For sounds that need to be looped, hitting the little E button next to the loop dialogue boxes automatically opens Logic's Sample editor where the region looping markers may be used to set the loop points. Once these are adjusted, their values appear automatically in the Zone dialogue boxes, but the values don't seem to update if you merely select a region and then designate it as a loop without making further adjustments. This is an 'issue' which Emagic have already been made aware of (apparently software companies don't use the word 'bug' any more!) — it's not a problem once you know about it, but it still needs fixing.

Logic is clever enough to set its loop markers at zero‑crossing points, but that's not always enough to guarantee a glitch‑free loop. To get around this, the EXS24 Zone edit dialogue box also offers a non‑destructive crossfade dialogue box where you can specify a suitable crossfade time to smooth the join. I spent ages looking for this dialogue box (I could see it in the manual but not on my computer screen) before discovering that I needed to go to the Zone View options menu and select View All. If you don't do this, the crossfade box remains hidden.

Using The EXS24

Considering that this is the first version of a brand‑new product, it worked extremely well and very quickly had me wondering whether I'd ever need my old hardware sampler again. The software only really falls down slightly in the first stage of the sampling process itself: most hardware samplers have audio triggering to start the sampling process and you can set a sample duration to stop sampling, whereas here you need to record the samples in Logic Audio or some other audio program, trim them, then import them into the sampler.

However, after the initial sampling process is complete, EXS24 wins over its hardware counterparts on almost every count. It successfully combines the immediacy of a virtual synth with the flexibility of a sampler, and it gives the user access to further processing using any VST/Logic effect plug‑ins. Furthermore, all the control parameters may be automated by moving the virtual knobs while recording MIDI data, and when you open up a Logic Audio song, any sampled parts load up automatically, ready to roll. No more trying to remember which sample CD that Tibetan Throat Singer sample was on and then waiting two minutes for it to load once you've finally located it.

Though EXS24 can work at 24‑bit/96kHz, it would probably be a rash misuse of RAM and CPU capacity to do so except in exceptional circumstances (though the 32‑bit internal signal path means this works exceptionally well with virtually no chance of overloading anything). Its 16‑bit sound quality is absolutely fine and is limited only by the quality of the original samples and the converters on the soundcard. Even where the source sample is a little noisy, you can use the filter section to close down the bandwidth as the sound decays, much like a dynamic noise filter, so even averagely recorded material can still be made very usable. The filter itself sounds nicely musical, though it does have the familiar digital characteristic of seeming to step rather than glide through the harmonics of the sound being processed when set near to maximum resonance.

The sampler integrates within Logic Audio nicely, except for one minor problem I encountered: you can't yet use the Loop function with virtual instruments, so if you want a long repeating section, you need to copy parts. Furthermore, aliases don't seem to work either.

Summary

I could go on for a long time about the technicalities of EXS24, but for me its real appeal is its ease of use when compared to its hardware equivalent. Few people ever get around to creating their own programs on a hardware machine due to the complexity of keygrouping and looping, but EXS24 positively invites it. Instead of setting up arcane multitimbral modes, you simply open a new sampler for each part you want to play and then load in the Instruments of choice from your hard drive. Loading in samples is very fast and the virtual front panel makes adjusting envelopes or filter settings infinitely easier than wading through menus. What's more, you can use as much sample memory as your computer has spare RAM. Its unwillingness to import Akai filter settings (see box, right) and its lack of any means to organise your sample library on your hard drive are a little irksome, but these operational niggles really are minor compared to EXS24's benefits.

I'm well aware that I under‑use my hardware sampler, because quite frankly life is too short to jump through all the necessary hoops every time I want to do something that ought to be fairly simple. EXS24 lets you work with samples without the user interface distracting you from the music, and there aren't many hi‑tech recording products you can say that about. I think it would be true to say that EXS24 is the most practical and inspiring piece of music software I've come across since Logic itself. Watch out for my hardware sampler in the SOS free ads!