Keyboard Magazine "In The Studio"
Article # 3
LOOKING FOR THE PERFECT SAMPLE
By Bobby Nathan
With the advent of sampling technology came a whole new way to look at keyboards. Unlike conventional synthesizers this new breed of sampling instrument has given us the freedom of hearing what we want, sampling it and playing it back by triggering the sampled sound(s) from the keyboard. After a sound has been sampled it may then be synthesized using the sampling intrument's VCF, VCF envelope and the VCA. For instance; you sample a piano and then give it the envelope of a violin. But I'd rather tell you more about the art of sampling which is a whole other story.
Unlike most synthesizers, frequency response is the key factor for a sampling intrument to sound good. Even the most inexpensive anolog synthesizers have greater frequency response than the most expensive sampler. But then again synthesizers try to mimic or synthesize a sound and samplers reproduce sounds. Sampling instruments are also limited by the quality of the sample. How well the sample was recorded into a sampling instrument is all dependent on the following parameters: the tuning and intonation of the instrument or voice sampled, the miking technique, the quality of the microphone preamplifier, the equalization of the microphone, and the level at which it was recorded into the sampling instrument.
Taking for granted that most of you out there already own a sampling instrument I'm going to skip over the obvious. Certain sampling instruments operate on a ratio of sample time vs. frequency response. Those of you who already own instruments that operate on that scheme probably have experimented with shorter sampling times to obtain a better frequency response of the sampled sound. If you haven't, you should. Other sampling instruments do not work on that scheme and the sampling time can vary with no change in frequency response. I feel a sampling intrument should be thought of as a digital tape recorder that uses diskettes instead of tape for storage. All the rules for making good recordings on tape apply to making great samples. I will try to give you some insight from a recording engineer's point of view.
First, tune up! Piano's and guitars have certain harmonics that are present when the instrument is in tune. Even though you many only be sampling one or two notes of an instrument make sure that the entire instrument is in tune. The better the musicianship the better the quality of the sample too!
If your are sampling electronic musical instruments (i.e. synthesizers,electric pianios, guitars and/or bass, etc.) that have unbalanced outputs (1/4" phone plug jacks), using a direct box can improve your samples immediately. There are two types of direct boxes "active" and "passive". Active direct boxes are infinetly better in almost all cases and equally more expensive but well worth it! Experiment with the ground lift switch on your direct box. Also by using a ground lift adapter on the AC lines of your sampling instrument or the electronic instruments you are sampling you can help reduce grounding noise and 60 cycle hum that would have been present on your samples. Patching your direct box into a console would then be the next improvement in obtaining cleaner sounding samples. Obviously the better the console the cleaner and more defined the sound. A console will enable you to add equalization to the sound source. Using a equalizer can be really helpful in adding character to a instrument that normally would need "EQ" anyhow (i.e. Fender Rhodes, guitar, etc.). Another advantage of using a console is that you are by-passing the microphone input of your sampling instrument making good use of the line input instead (some sampling instruments don't even have microphone inputs! ). There are still certain instruments that can sound more interesting when sampled with a microphone. You will still need a console if your sampler doesn't have a balanced microphone input. For certain instruments the direct signal can't compare to miking the instrument through a guitar amp and/or a PA system for the desired equalization, speaker distortion and/or ambience required. Reverb, digital delay and flanging/phasing/chorusing all help make samples much more exciting and free up those outboard effects for other uses on stage later. If you are trying to sample synthesizers try this: sample your favorite patch with the filter open full. The filter's envelope and the VCA should be set with the attack fast as posible and the decay, sustain and release open. This practice works great if your sampling instrument has complete VCF/VCA control. By leaving the filter and the envelope wide open when sampling, you can close them down later and thus basically come very close to duplicating the control of the original synthesizer's filter and envelope. Of course no two manufactures filters and envelopes can produce the same results but here's where you can take the basic waveform and obtain new results. If your sampling instrument does not have any or limited control this would not be the best way to sample another synthesizer for you. Instead sample the patch the way you like it. If the filter sweep or the LFO delay is longer than the sampling time available, adjust the synthesizer so that their effect is minimal. After you have looped the sound use the VCA and the LFO on your sampling instrument to get back the original effect(s). If you have created a collossal midi sound using a couple of synths, sampling can be faster than trying to duplicate the patches. If you are trying to sample live sounds such as strings, voices horns, etc., these sounds require the use of a microphone. You do not neccesarily have to be in a recording studio to sample live sounds. Sampling sounds in different environments is real interesting. Auditoriums, gymnasiums, churches and subway tunnels are just a few examples. Another important aspect is microphone placement, which microphone to use for certain instruments and under what conditions. This knowledge can be obtained through books or by getting your sound man to help you. Don't have a sound man? Hire one to learn from or spend some time and experiment. Remember the key word in sampling is experimentation!
Compression is also a big factor. Outboard compression works great on voices, strings, pianos, etc. Setting the attack of the compressor to allow the initial attack of the sound to pass untouched and then compressing the rest of the sound works great for recording samples with a punch (i.e. piano). Tape compression works great too. If you don't own a compressor but own a tape recorder with three heads try this: record the sound you want to sample to tape first. Listen to the playback head while you are recording the sound and experiment with volume levels hotter than you would normally record with. You will hear the effect of compression as you are recording it. Of course if you record a sound to hot it will distort. After it has been recorded to tape then sample it. Bass guitar and bass synth will have much more punch when sampled thru a compressor. Onstage, your amplifier's speakers will love you for it. If your console is noisey, some of the single ended noise reduction boxes created for guitarists can solve that problem in a hurry.
Experiment with certain types of instrument(s) and voice(s) by sampling them without vibrato or tremlo. These effects can make looping a sample harder later. This technique will allow you to add any desired amount of tremlo or vibrato later. Again in some cases the natural vibrato of a violinists bow can make a string sample seem to sound more realistic. The same holds true with vocalists.
So far I've talked about getting the sound into the sampling instrument. Mastering the art of multi-sampling is important too. Understanding multi-sampling and your instrument's capabilities will help you to know which notes to sample. Depending on the architecture of the instrument you are using, some thought has to be taken in regards to how many multi-samples can be had. To make your samples sound more realistic, you have to know which notes are most characteristic of the instrument you are sampling! You always have to juggle how much total sample time you have left divided by the number of samples needed. Sampling two octaves of voices for instance can require multi-sampling those voices every major third. You can always hear "munchkinazation" when trying to transpose a voice or horn more than a major third. Once again experimentation with how much memory you have, and how many samples you can have vs. how far you can transpose a sample is the key to making better multi-samples.
When you are dealing with a sampled sound it is important to make sure there is no noise before the beginning of the sample and/or after the end of the sample. For example if you do not edit noise off the front of a sample it will cause the attack of the sound to be delayed when the key on the keyboard of a sampling instrument is depressed. Being able to see a sampled sound on a CRT can be very powerful in aiding one to edit or truncate ( taking noise off the begining or end of a sound ).
To get a sampled sound to sustain longer than its total sampled length, understanding looping is essential! When looping, pick a point after the inital attack of a sampled sound where the loop will start. A good rule for figuring out the length of a loop is the length of the loop should be equal to the length of the waveform, filter sweep or vibrato. Being able to see these points on a CRT is a great help in looping your sampled sounds quickly. If your system doesn't support a CRT, don't abandon ship! You can learn to truncate and loop quickly without a monitor too! Some samplers have auto-loop software to make the looping process quite painless.
Sampling instruments do have their drawbacks. The easiest way to over come them is not to expect more from a sampled sound than the sample has to give! For example if you have sampled legato strings don't expect to play staccato string riffs with that sample and vice-versa. It's not going to work! Like the best of sound patches on a anolog or digital synthesizer, samples too have a limited range of versatility. It is up to the keyboard player's technique to get the best of what he has to work with. There are some experienced synthesists that can still make big clunky modular anolog synthesizers sound more like real strings than a novice synthesist on the best sampling instrument. But that is an art in itself.
Back to Bobby "Guitar" Nathan's Keyboard Magazine Articles Page
copyright 1985 - Bobby Nathan - May not be used without consent!