Virtual Sampling

Sampling was once the exclusive domain of hardware manufacturers such as Roland, E-mu, Akai, and Kurzweil. In recent years, however, sampling has emerged
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Sampling was once the exclusive domain of hardware manufacturers such as Roland, E-mu, Akai, and Kurzweil. In recent years, however, sampling has emerged as a viable music production tool in desktop-only systems. If you have a computer that's at least moderately fast, a software-based sampler is worth considering as a means of expanding your creative palette.

Software samplers offer a number of important advantages over their hardware counterparts. For starters, they're often easier to use because they provide dedicated onscreen controls for every parameter. That's a big improvement over the limited number of multifunction knobs and switches typically found on hardware samplers. Moreover, the best software samplers cost quite a bit less than most dedicated hardware units, and it's far easier to upgrade a software sampler than it is to enhance a hardware unit's capabilities. You'll also have a near-limitless amount of "memory" for loading and playing back samples if your software sampler plays sound files directly from disk-which at least one of the programs does.

Currently, the best-known software samplers are Reality from Seer Systems, Unity DS-1 from BitHeadz, GigaSampler from NemeSys, and Transformator from Native Instruments. Reality and GigaSampler are Windows-based applications; Unity DS-1 and Transformator are cross-platform (Mac and PC). You may also encounter a number of other lesser-known programs, including Space Station Pro, a DOS program from Digital Audio Innovation, and the interesting Mac application Lisa, by Tom Demeyer of the STEIM research group.

As powerful and intuitive as these programs are, it still pays to learn as much as you can about this type of software and how to use it, to make sure you get the best possible performance. In this article we'll explore some of the issues related to using a software sampler, and we'll also look closely at various downloadable sound-file formats that you can use with many of the programs. We'll also take a passing look at the sampling capabilities that many sound cards now offer, especially for the PC.

Conquering LimitationsAs you might expect, you'll get the best results if you run a software sampler on a computer with the latest processor, a fast hard drive, and loads of RAM. If you intend to use a software sampler as part of a computer-based sequencing and hard disk recording environment, the need for a powerful computer becomes even more critical.

Many software sampler manufacturers specify minimum system requirements (though you can never have too much RAM or too fast a CPU). NemeSys, for example, specifies a Pentium 166/MMX with 32 MB of RAM and a fast hard drive as the minimum configuration for its GigaSampler. I work with a Pentium II/266 with 128 MB of RAM, an Adaptec 2940 Ultra SCSI controller, a Seagate Cheetah hard drive, and an Ensoniq PCI sound card. But one of the first lessons I learned is that horsepower isn't everything.

Working with Cubase VST 3.6, I configured my system (using ASIO) so that GigaSampler received the MIDI data sent out by Cubase; in effect, GigaSampler became another instrument in my studio (see Fig. 1). This worked fine, but only to a point. When I loaded an audio file into Cubase and tried to play it back while also sending MIDI data to the sampler, I fell into a pothole I hadn't expected.

It turns out that the ASIO driver would not allow both software applications to address the sound card at the same time. This rather serious limitation, which is a problem on both the Mac and the PC, has now been resolved with the release of the ASIO 2.0 specification. Of course, software manufacturers will need to implement the new spec before users can take advantage of it.

One work-around for this problem is to use Steinberg's ReWire, an application that takes the audio output from software synths and samplers and routes it directly into the Cubase mixer (see Fig. 2). When you use ReWire, Cubase becomes the only program talking to the sound card. Of the software samplers mentioned earlier, however, only Unity DS-1 for the Mac works with ReWire as of this writing. (Unity DS-1 for the PC should also support ReWire by the time you read this.) Other software samplers and synthesizers should jump on board as more sequencers support the ReWire protocol. Cubase and Opcode's Vision work with ReWire now; Emagic has announced that it will support ReWire in its Logic Audio series.

If your software does not support ReWire (as is the case with GigaSampler), one option is to record your software sampler's output to disk as a sound file, then import the file into your digital audio sequencer as an audio track. This is done by enabling the Capture to Disk feature in your sampler program. Another solution is to use a second sound card (the option that worked for me) or to use a card with multiple outputs. Each pair of outputs should appear to your operating system as a separate sound device. Even then, however, not all multichannel cards support multiple "clients." (More on sound cards in a moment.)

Seer Systems' Reality offers yet another option. Using the Reality Wave driver (a utility that is installed when you load the software), you can send audio from any digital audio program into Reality (see Fig. 3). The incoming audio is mixed with Reality's own output and sent to the sound card. Reality even provides a slider to balance the audio parts, or you can set the level of the audio coming out of your sequencer at its source. This solution works well and gives you the ability to send both MIDI data and audio information to Reality in real time. (You can load a Standard MIDI File directly into Reality-who needs a sequencer, anyway?-but, of course, you won't be able to play back other audio tracks at that point.)

Pick a CardThough most software samplers work with most sound cards, some samplers have very strict timing requirements and therefore work with fewer cards. GigaSampler, for example, supports a reasonable number of cards, but you need to check the company's Web site to be sure your own hardware is on the list.

Reality, which initially worked only with Sound Blaster cards, can now coexist with any card that has DirectSound support or can run in DirectSound emulation mode. It also works with the WAV drivers provided by certain cards. All WAV drivers are not created equal, however, and you'll have to check the company's Web site to verify that your card is supported.

Unity DS-1 and Transformator are completely happy with any PC audio card that has ASIO or DirectSound drivers. (Transformator will also work with a standard Windows MME card, but as always, performance varies depending on the card.) On the Mac, these two programs should perform well with any audio hardware, including the Mac's native audio with Sound Manager. Unity may introduce a bit of latency if your card does not allow you to tweak its buffer size, but that's a fairly uncommon limitation. Transformator has built-in options for tweaking its performance with whatever hardware you throw at it, so here too latency is rarely a problem (see Fig. 4).

Pro Tools users will gain additional benefits from using a software sampler with DirectConnect, a multiclient audio protocol that should be available by the time you read this. E-mu has already built multiclient ASIO support into its APS card, so you can use two ASIO-compatible audio applications if you own that card.

One other trend in sound cards is very promising for software sampler users: several new cards offer hardware mixing (aka DirectSound acceleration). The Sound Blaster Live, E-mu APS, Turtle Beach Montego, and others provide this feature. Soundscape's Mixtreme also provides it, though it doesn't have (or need) DirectSound drivers. With this feature, the hardware is responsible for mixing multiple applications into one or more sets of stereo outputs. For instance, with the Mixtreme system and Reality, you can run your digital audio sequencer and Reality at the same time. You could route Reality into Mixtreme (via Wave drivers), apply a TC Works reverb and a compressor/limiter using the DSP on the card, and then route it back into an audio input of the sequencer, all in real time. This is totally cool and is the way more cards will be implemented in the future.

Sounds Like?With the growth of the Internet, the explosion in computer gaming, and the general trend toward all things multimedia, musicians have become more insistent that their compositions be played back with the sounds they initially used in creating their works. Delivering those sounds to the end user, however, is no small task. General MIDI was supposed to resolve the problem, but the differences between the synthesis methods used by manufacturers still limit composers' ability to ensure that their work will sound exactly the same regardless of where it is played.

Fortunately, we can now deliver actual sample data along with the MIDI notes that constitute our compositions. This is possible if you use a software sampler or sample-based sound card that supports a downloadable sound-file format. The vast majority of multimedia sound cards have this option, as do Reality and Unity DS-1. Unfortunately, there are several data formats currently in use, which has resulted in a rather confusing state of the art.

Formats for MultimediaTwo of the most popular file formats for multimedia are DLS (Downloadable Sounds) and SoundFonts. SoundFonts were created by E-mu's parent company, Creative Labs, for use in the company's Sound Blaster sound cards. This format allows actual sound (sample) data and its associated performance parameters to be downloaded to a supported sound card or software sampler. The sounds can then be played back via MIDI. Some sound cards, such as E-mu's popular Audio Production Studio (APS) and the new Creative Sound Blaster Live, can hold as much as 32 MB of SoundFonts in RAM. Reality and Unity DS-1 provide support for file sizes up to the limits of free RAM in your system.

The process of loading a card with the desired sounds is quite easy. Most cards ship with a control panel utility, such as the E-mu SoundFont Manager, which lets you manage your sound library and configure the card with alternate sound sets. Such utilities also typically have functions to restore a card to its default condition and to control parameters such as DSP effects for reverb, chorus, and spatial settings. More sophisticated options are available in dedicated SoundFont editors such as Vienna, which ships with most Creative Labs cards (see Fig. 5). Vienna provides extensive sound-design capabilities for tweaking your sounds.

Loading a SoundFont into a software sampler is even easier. In Reality, for example, just select the Add Bankset option from the File menu, then point the program to the directory containing your files. You'll be able to access nearly all the parameters of the original SoundFont in Reality, and of course you can edit the sounds any way you wish. When you're done tweaking the files, you can even tell Reality to create an instrument definition file (a list of your presets) in the format of many popular sequencers. On the E-mu Web site, for a mere $29.95, you could purchase all the original sounds and performance data from the E-mu Proteus III (World Music) sound module in SoundFont format. That kind of bargain doesn't come along too often!

It should be noted that programs such as Cubase VST and Cakewalk Pro Audio also provide support for SoundFonts and allow you to load a compatible sound card with alternate sounds without having to open a separate program. (You can't, however, load a bank directly into a software sampler from these applications.) You may need to have a SoundFont manager installed to take advantage of this feature.

The DLS format was developed by members of the Interactive Audio Special Interest Group and leading multimedia companies, including Advanced Micro Devices, IBM, Microsoft, Yamaha, and Creative Labs. Targeted for CD-ROM and Internet entertainment applications, DLS, like the SoundFonts format, is designed to provide composers and game developers with the ability to add their own sounds to the user's system while not relying on a fixed GM sound set. The result is a universal delivery system that allows a musical performance to be realized as the composer envisioned it. (Additional information on DLS software tools is available at www.midi.org/dlstools.htm. Also see "Desktop Musician: Down and Out in Cyberspace" in the December 1998 issue of EM for more on downloadable sounds.)

Configuring the end user's sound card is generally a transparent process; the sounds are installed when a game is first loaded. DLS-compatible devices enter a special "DLS mode" upon receipt of the following MIDI System Exclusive message: F0h 7Eh 0Ah 02h F7h. Once in this mode, the sound card can put the downloaded sound into any designated bank and instrument location while avoiding conflicts with other modes such as GM, GS, and XG. As with a GM-compatible device, a minimum of 24 simultaneous voices is supported. Currently, a large number of cards can work with DLS files, including the Turtle Beach Montego II, and several cards from TerraTec. You can also use the format with Unity DS-1.

One-Stop ShoppingOnce you've explored some of the various file formats, buying new sounds for your software sampler or sound card should be a bit easier. Although you can find hundreds of SoundFont and DLS files online (see the sidebar "Sites for Sounds"), there are other options to consider.

Using a file conversion program such as FMJ-Software's Awave or Chicken Systems' Translator, you can open files in many different formats, like those used by various hardware samplers, then convert them into a format that your software sampler or sound card can use. Awave, for example, can convert between more than 100 different audio formats, including Yamaha, Roland, and, of course, AIFF, WAV, and SDII. Translator also supports dozens of formats and is especially suitable for working with sounds in the various Ensoniq formats. GigaSampler and Unity DS-1, on the other hand, can read Akai sample formats directly. These options open the door to an endless number of sounds that you can use in your projects.

When buying sounds on CD, try to purchase CD-ROMs rather than audio CDs, because CD-ROMs typically include both the sample and the performance data. You simply load the file and you're ready to play. In contrast, audio sample CDs are composed of raw data, which forces you to loop, multisample, and create all the various performance parameters that constitute a finished patch. Similarly, when you download samples from the Internet, you normally get only the raw sound data, not the performance parameters.

Toss Your Hardware?The current generation of software samplers is fully capable of functioning on a par with its hardware cousins, and as our computers get faster, these programs will only improve. We have the ability today to take advantage of sampling technology at a fraction of the price that was common just a short while ago, and the number of available sample libraries is nothing short of astounding.

So, should you throw away your hardware sampler? That's a tough call; it depends on your needs and your work environment. There are clear limits to working with a software sampler, such as the inability to run two audio programs at once with some sound cards. Furthermore, there's no question that the performance you achieve with any of these programs depends very much on the type of computer you're using. Nevertheless, many of today's limitations will disappear shortly, and as we all know, computing horsepower will increase as well. That should soon make software sampling one of the most efficient things you can ask your computer to do.

Roger Maycock is a Los Angeles-based consultant for digital audio and recording applications. Special thanks to Mark Hiskey of Ilio Entertainments, Costa Kotselas of Steinberg North America, Todd Shires of E-mu, Earl Sondreal of BitHeadz, and David Roach of Seer Systems.

If you are looking for sound data to expand your sample library, the Internet is a great place to start your search. Though dozens of Web sites offer free and commercial samples, the sites that are listed here are among the best-known and offer some of the most comprehensive collections of sample data and other music-related offerings.

One of the most comprehensive sites for sampled sounds is Sounds Online (www.eastwestsounds.com). In addition to offering a limited number of free samples for downloading, it has a highly organized database that lets you search by category or for specific CD-ROM titles (see Fig. A). You can also shop for various kinds of music software-everything from source music libraries to applications to help you clean up your sound files.

Q Up Arts (www.quparts.com) bills itself as the provider of "the world's most unique collection of sample CDs and CD-ROMs." This site is unique in that it provides you with a narrated description, in either RealAudio or MP3 format, of the sounds in any given collection. The description provides a clear understanding of the contents of any CD-ROM that you might consider purchasing. The disc formats (Akai, E-mu, and so on) are clearly identified.

Sampleheads is well known for its collections of CD-ROM sample discs, and the Sampleheads Web site (www.sampleheads.com) provides visitors with a concise description of each CD in the company's stable. The site also allows visitors to audition sounds from each collection via RealAudio, provides explanations of CD format issues, and offers audio CD and CD-ROM discussions.

Ilio Entertainments (www.ilio.com) offers numerous music software titles in addition to its online sample collection. Ilio's Web site is noteworthy for its FAQ list, which addresses many sampling-related issues. A special area delves into the topic of licensing sound data. You'll also find a Tips and Tricks area that discusses optimizing a sampler's gain output for getting the best sound quality for your efforts.

Jennifer Hruska's Sonic Implants site (www.hruskaudio.com) offers several highly regarded collections of SoundFonts for purchase. Game composers, in particular, will like the Industrial Dance PC and Retro Synth PC collections, which are replacements for the standard GM set. Custom collections and ports to other formats are also available, and you can pick up an occasional free sample in the Sonic Leftover area of the site.

After arriving at the German-language Best Service Web site (www.bestservice.de), the first thing most of you will want to do is click on the hyperlink that takes you to the English portion of the site. Best Service carries sample CDs from numerous companies and also has database facilities that let you perform selective searches for the type of sound data you want. Best Service has a full complement of music software titles in addition to its collections of sample data. Unfortunately, certain hyperlinks take you back into the German-language zone.

One of the biggest names in music retailing, Sweetwater Sound (www.sweetwater.com), carries everything the professional musician could reasonably expect to find on a Web site. You can purchase equipment, explore the company's tech library, or download and purchase sampled sounds and sample CDs. You can even post your resume or go looking for your next industry gig. You can also audition sounds from Sweetwater's sizable collection, and the price of any individual sounds that you purchase is deducted from the price of the CD version should you later buy the entire disc.