The EM Poll

Experimenting with SoundFonts

Apr 1, 2005 12:00 PM, By Kurt Heiden

           

Keeping track of which bank is loaded into the default GM Bank 0 and which are loaded into higher-numbered banks requires a bank-management system. A few MIDI sequencers, including Sonar and Cubase, have built-in SoundFont bank management. PC users with an Audigy or new Creative sound card also get a very functional utility called SoundFont Bank Manager, which lets you manage your sample banks. By clicking on the MIDI Devices button in this program, you can adjust the amount of RAM allocated for SoundFont use. The default is only 12 MB, so that would rule out some of the more robust GM bank alternatives, such as the 24 MB GM set from Sonic Implants. I keep mine at about 100 MB so I can switch among banks at a moment's notice. Users of software synths, including those under Mac OS X, will not need to allocate RAM, as any software synth you use should do it for you dynamically.

The View from the Deck

Now that you've tackled the default GM bank, you'll probably want to investigate adding other SoundFont libraries. Look for quality instrument samples followed by generous amounts of tweaking on the parameters. The SoundFont format supports layering, panning, and detuning Instruments, adding reverb or chorus, adjusting filter cutoff, Velocity switching, and much more. The best commercially available SoundFont banks will exploit these features to create professional-quality Presets. In general, most commercially available banks are likely to use better samples and be of higher quality than the free goods you'll find all over the Internet.

To load and manage a SoundFont bank other than Bank 0 on Mac OS 9, you'll need a Sound Blaster Live card for Macintosh. If you're lucky enough to have one, you'll need to install only the software that came with it. In addition to a bank manager and Preset editor called SoundFont Bank Manager 1.1, you'll have a handy Control Panel that will let you modify the amount of RAM that your SoundFonts can use.

FIG. 3: Swapping banks within GarageBand is simple when using Andy Drabble’s SoundFont Synth 2.0.

A valuable download for Mac OS X users who want to load and manage banks is Andy Drabble's SoundFont Synth 2.0. It's an Audio Units (AU) plug-in that allows loading of any SoundFont bank within any AU-capable application, including GarageBand, Logic, and MOTU Digital Performer. Fig. 3 shows SoundFont Synth in GarageBand. Here it is being used to replace the Laser Shot sound from the default Apple GM bank (left) with the Lazer Gun Instrument found in Sonic Implants' 24 MB GM bank (right).

Under OS X, Apple's built-in SoundFont-capable synthesizer, DLSMusicDevice, is addressed as an AU plug-in. SoundFont or DLS banks can be swapped inside DLSMusicDevice, and because it's a plug-in, it shows up in any AU-capable host application, including Apple's EXS24 Sampler within Logic Pro 7, GarageBand, and Granted Software's Rax. (Rax is a great way to manage banks within Apple's built-in synthesizer and SoundFont Synth 2.0 simultaneously.)

Note that SoundFont bank managers on the Mac OS typically refer to Presets as Instruments, a convention used by the DLS specification (DLS support appeared on the Mac before SoundFont support). That can be confusing because, unlike Presets, the Instrument level in a SoundFont bank does not have a bank number, patch number, or patch name. When you see “Instruments” on most SoundFont synths/samplers while working with SoundFont banks in OS X, you're actually working at the bank's Preset level.

Under Windows, the process of bank management will vary depending on the Sound Blaster card you're using. (If you don't have a Sound Blaster Live card, you'll need to pick up a software sampler or synthesizer with SoundFont support to do bank management.) Sound Blaster Live or Audigy sound-card owners will find a SoundFont Librarian/Manager under the Creative menu in their Start menu.

If you're using a PC and are serious about SoundFonts, I recommend that you purchase a used or refurbished Audigy Platinum sound card (available on Ebay for less than $100) because it has MIDI In and Out. That card is also the most flexible in adjusting sample RAM and has the most up-to-date SoundFont management tools. Be sure to crank up the amount of available RAM assigned to SoundFonts by using the SoundFont Librarian/Manager, as the default is only 12 MB.

FIG. 4: Cakewalk’s Sonar has an option to attach a SoundFont file to a bank. The Attach menu (right) shows the SoundFonts currently assigned as banks for use in the Track area (left).

Windows users should note that Cakewalk's Sonar has a SoundFont bank manager conveniently listed on its Options menu. (That option appears if you have SoundFont hardware present. See Fig. 4.) Simply open the SoundFont menu item, select bank 1 (or any other available bank), click on the Attach button, then click on Close. Now assign the bank to any track's Bank field, and all of the Preset names will show up on that track's Patch drop-down menu. That makes bank management quick and easy, so check your sequencer of choice to see if it contains a similar feature. Sonar 4 users without SoundFont hardware can use the included DS864 software sampler to load a SoundFont bank as a Dxi instrument.

Below Deck

Although there are many high-quality banks on the market, you'll get the urge to make your own at some point. (See the sidebar “Jen's Top SoundFont Tips” for additional ideas on SoundFont creation from Jennifer Hruska, founder and president of Sonic Implants, a division of Sonic Network, Inc.) One of the first decisions you'll have to make is what sampling rate to use. The choice of rate when recording samples for SoundFont banks depends on the capabilities of the synth that will render the banks and whether you're trying to keep bank size to a minimum.

For the best-quality sampling on a Sound Blaster Live or Audigy sound card, sample at 16-bit, 48 Khz, before importing your files into your editor. Those cards work natively at 48 Khz, and other sampling rates will be converted up or down automatically. If you create banks with a high sampling rate and someone plays them back on a SoundFont synth that renders only at lower rates, they will be scaled as well. If you're using a software synth to render your SoundFonts, you may have more flexibility. For example, check with the manufacturer to find out if they support high sampling rates such as 96 Khz.

If keeping bank size small is important or, if artistic needs call for low-fidelity samples, use lower sampling rates. Your own tastes may vary, but most people won't hear a loss of fidelity until you dip below 22 Khz, especially if they're using multimedia speakers attached to their computer. Note that you can create stylized effects, such as a vocal that's supposed to sound as though it's coming from a tiny speaker or a looping scratchy-record effect if you use ultralow sampling rates.

If you know that you're going to be using large samples but want to keep SoundFont bank size low, an alternative to using lower sampling rates is to use compression. A utility from Melody Machine called sfark allows you to use lossless compression within a bank to save space. Although I haven't tried it, consensus from online forums and my conversations with E-mu is that it works well and is quite popular with size-conscious SoundFont bank authors.

When you're ready to sample, start with clean, quality mono or stereo samples in WAV or AIFF format. If you want sampled vocals in your SoundFont bank, be sure to use a good microphone and a compressor/limiter as needed and do any other processing that you want before adding the vocal to your mix. Once imported, you'll be able to create harmonies by doubling samples and changing their pitch, but you may find that using professional processing equipment for harmonizing prior to importing vocals offers more desirable results than simply changing a sample's pitch.

When your samples are ready, you'll need a SoundFont editor to finish the job. Editors are used to make modifications to existing banks or create new ones from scratch.

There's no full-featured editor for Mac OS X yet, but I recommend Best Software Design's Polyphontics, because it's as close as you can get. Polyphontics doesn't have all the command-line requirements of some other editors, and it allows you to import samples from existing SoundFont banks or record new samples and then use them to create new Instruments. Once imported, you can set loop points, assign multiple samples to different key ranges within an Instrument, add reverb, and adjust envelopes and panning. There's no support for Global Zones or tweaking of most other SoundFont parameters, but otherwise, Polyphontics does a solid job.
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SIDEBAR
Meeting with Captain Thorn
I managed to spend some time with George Thorn, Worldwide Director of Creative Labs' Developer Relations. Some amazing advances are coming in 2005, when we'll see the first major revision since SoundFont 2.1 was introduced in 1998. The next spec, which will be numbered SoundFont 2.4, will include support for 24-bit sampling that is scalable to older, 16-bit SoundFont engines. That is great news because with scalability from SoundFont 2.1 to SoundFont 2.4, you'll be able to create your SoundFont banks in 24-bit as an author-once, render-everywhere solution. In addition, it appears that E-mu and Creative are going to be the first to bring 3-D positional surround MIDI controllers to the mix.

Although specifics are not available on what kind of hardware is going to power this new generation of SoundFonts, I'm sure that it will be equally amazing. Look for release of new products before the year ends.