Going Beyond Presets

Jul 1, 2009 12:00 PM, By Larry the O

           
 

FIVE TOP SOUND DESIGNERS OFFER TIPS FOR GETTING THE MOST FROM YOUR SYNTHS

FIG. 4: Modulating the time within a sample at which it starts playing back can add life to the sound. This drop-down menu shows the variety of sources available in Spectrasonics Omnisphere for sample start modulation. (The Sample Start parameter itself is obscured by the drop-down menu in this illustration.)

Pitch stretching, as described in the sidebar “Better Sounds Through Pitch Stretching” below, is a technique that employs timbral modulation rather than dynamics processing to make each note different.

Hotop also views envelopes as powerful tools for adding expressivity. “A lot of synths and workstations have sliders and knobs that make it easy to say things like, ‘How about if I extend the release on this patch so that I don't have to pedal as much and I can play with a legato touch.’ That is often an easy parameter to find these days, and, a lot of times, just a little tweak like that can make a sound work better in a track or fit better in the sound of a band for live performance.”

Persing offers another technique to liven up a sound: “If you modulate the sample start time so that you're never hearing the same sample playing in the same place every time you hit the key, it puts just a little subtle variation in there and the sound really feels much more alive [see Fig. 4]. The musician may not be able to put his or her finger on it, but when you play the instrument, it sounds good, it sounds alive, it doesn't have that dead feeling of a ‘boring old sample.’”

Of course, there will always be a place for aimless experimentation and just following your muse. But understanding your instrument and how to maximize what it has to offer is a gateway to finding your individual voice on it and extracting the expressiveness we all seek in making music.

Larry the O has programmed synthesizers since the mid-'70s, and has contributed to EM since 1986. His company, Toys In the Attic, provides sound design and music composition services. He wishes to give special thanks to John Lehmkuhl for the abundant quantity of materials he provided for this article.

Better Sounds Through Pitch Stretching

“The problem with a sampled sound is that it's a snapshot,” says Eric Persing. In other words, hitting the same key three times in a row produces the exact same sound three times, unlike an acoustic instrument in which every note will have at least slight differences. But Jack Hotop and Persing describe one of the methods for countering this problem.

“There's a great technique called pitch stretching, and there's a couple of ways of achieving it,” says Hotop. “If you bend or transpose the pitch of a sample up, it gets brighter in harmonic content. You might do this using an envelope, or a parameter called something like ‘pitch adjust’ or ‘pitch stretching.’ What it does is change the tonal and timbral character of the sound.

“If you bend the pitch down by anywhere from a half-step to an octave, you'll find that the timbre becomes darker,” Hotop continues. “It's just a way of evoking different tones. My first experience with this was back in the days of the Mellotron, where I'd use the pitch control, but then have to transpose the part I was playing and play it in a different key [to bring it back to the desired pitch].

“With synthesizers and workstations now, you have transpose functions, so raise or lower the pitch of the sample, and then use an offset for the transpose function. Some synths and workstations have a parameter you can just adjust and it does that; on others it's a programming trick you can do if you modulate the pitch with an envelope, keep it there with a high sustain level and do offsets that way. That's another way of getting different timbral characters.

“But remember that when, for instance, you lower the pitch of a sample, you're slowing the attacks of the sound down. Since you have the knowledge that the attack is going to be played at a slower rate, you can move the sample start point into the waveform a little bit past that initial attack so you don't get a klunk [see Fig. A].”

Persing describes the same technique as it is implemented in one of Spectrasonics' instruments. “We have a control in Omnisphere where you can shift the timbre of the sound, which works very simply by taking all of the keymaps and shifting them in one direction and then compensating for that by changing the pitch,” he says. (Omnisphere's Timbre Shift parameter can be seen in Fig. 4 just above the drop-down menu.) “What happens then is that all of the formants of the sound are changing without the pitches changing. We can modulate that parameter, too, so that every time you strike a key, you can randomize the shift (or use whatever modulation source you want to change it). That way, the instrument doesn't sound the same every time you hit a key. [see Web Clips 1a, 1b and 1c].”

Velocity Curves Ahead

Next to note timing, velocity is probably the most accessible mechanism for imparting the human touch to a synthesized or sampled part. Switchable velocity curves on a keyboard controller allow a user to contour the effect of velocity for each context. “In a keyboard, velocity is a measure of how fast you're playing the keys, and it's most often used to control volume, but it also can be used to control filtering and brightness, and envelope times, when velocity can be routed to envelope segments,” explains Jack Hotop. “When you change a global velocity curve, it can change the way a sound responds, and not just in terms of volume. It lets you take control of the sound.”