A Roland SPD-S Sampling Primer

Grade, Mode, And Their Effects On Polyphony

There are a few things you should know about the SPD-S and its polyphony – polyphony being the number of samples that can sound at the same time. Hey, I just said, “Polyphony!” Simply put, there isn’t a whole lot of it to spare. The SPD-S has eight-voice polyphony. That is to say, eight mono samples can sound at the same time. The samples can be individual hits like percussion sounds, or full-blown loops. But, as soon as the ninth simultaneous sound is played, the very first sound played will be cut off and stop sounding.

Notice that I said eight mono samples could sound at the same time. This is important. Because a stereo sample is just two mono samples locked together, a stereo sample uses two voices of polyphony. Quickly doing the math reveals that only four stereo samples can sound at the same time. The point being, you have to use your polyphony wisely, lest you quickly run out.

When saving samples, you will almost always be prompted to choose the Mode, (mono or stereo samples), as well as the sound’s Grade. Choosing the Grade from LONG, STANDARD, or FINE will help determine the final sonic quality of the sample. The pad’s default Grade setting is STANDARD. This Grade is CD quality, but has an ingenious compression scheme designed to minimize the space used when the sound is saved to memory. Honestly, I don’t think I’ve used any Grade other than STANDARD – it just sounds great. Guess that’s what happens when a bunch of MIT eggheads design your compression scheme!

LONG Grade squeezes the most sampling time out of the SPD-S, but at the cost of sound quality. I discourage the use of this Grade, as you do begin to hear some of the sample degradation.

FINE Grade sounds great, but also has a cost. Hang on to your hat and get out the abacus, there’s a little more math relating to FINE Grade and its effect on polyphony. When using FINE Grade to sample, which has no compression scheme at all, polyphony is cut in half. So, in FINE Grade only four voices of polyphony are available. Just four mono samples or two stereo samples will consume every bit of the polyphony! Because of this, a little planning should to take place before you actually begin sampling. Blindly charging ahead without planning ultimately creates much more work for you in the long run.

Uh, Mono Or Stereo Mode?

To determine what might be the best sample Mode, look at how the sample or loop will be used. Does it need to be sampled in stereo? If the answer to this question is anywhere in the same zip code as “no,” sample in mono. For almost all single-strike hits, mono is just fine. Also, samples and loops of instruments that are usually mono in the acoustic world, like bass, guitar, and cowbell – one can never have enough cowbell – work well living in mono.

Fig. 1

How Do I Load My Sounds?!

There are two ways to get new samples from an external source into the SPD-S: sampling directly into the SPD-S using the audio inputs on the back panel, and editing the sound on a computer and transferring it to the SPD-S via CF card. While some people prefer the simplicity of using just the SPD-S to sample and edit, others like editing on a computer because you’re able to see the waveform on the screen. Either way is easy to master because the user interface of the SPD-S is designed to make what used to be a very difficult process, easy. Dare I say, it’s almost “drummer proof!”

Much of this ease-of-use can be attributed to the user interface, which relies heavily on multi-color, backlit gel buttons (Fig. 1). The backlit button scheme helps guide you visually through the sampling process. Non-illuminated buttons are inactive. Active buttons needed for completing some part of the task at hand are continuously backlit. The lone flashing button is the one you would press to execute the next logical step in whatever process you engaged in. (There will never be more than one button flashing at a time.)

Fig.2

Sampling Via The Audio Inputs

The back panel of the SPD-S has two .25" audio inputs. They accept standard guitar cables. To sample using these inputs, simply plug in an external audio source. If you are using an audio source such as a CD player, mp3 player, or synthesizer, make sure the switch to the left of the inputs is set to LINE. If you are using a microphone, you’ll need an adapter to turn the mike’s XLR output into a .25" plug. Because microphones have a much lower output level than most other audio devices, like synthesizers, set the switch to MIC. This setting makes the audio inputs much more sensitive. To the right of the audio inputs you’ll find a knob marked LEVEL that is used to fine tune the input gain (aka, input level), once you start the sampling process (Fig. 2).

Notice that the left (L) audio input is also labelled MONO. Circuitry in the SPD-S senses if both the right (R) and left (L) inputs have jacks plugged into them, and automatically samples in stereo. It’s very important that when you want to sample in Mono, that just one cord is used and it is plugged into the left (L), MONO input. Not only do stereo samples eat up polyphony, they double the size of the associated sample file (Fig. 2).

Page 2 of 7