This is the first installment of a series of articles detailing how to program tight, effective analog bass lines and some of the best synths for achieving good bass sounds.
The art of programming good bass sounds is a tricky one that seems to elude even skilled analog programmers. Maybe worse, many of us are only familiar with one or two “methods” of programming analog synthesizers for bass sounds and restrict ourselves to only a handful of the potential sounds out there. The purpose of this series is to cover all aspects of programming analog synth bass sounds, as well as highlight some of the better synthesizers for achieving a solid bass sound. Additional articles will also detail recording and studio techniques that can further enhance the low end to your tracks.
One area often overlooked for programming bass sounds are the oscillators and setting them up properly to achieve a good tone. A common mistake among many users-including seasoned professionals-is the tendency to mix all of the oscillators at 100% volume. This may not always be effective for achieving the best bass sounds. For example: to fatten up a sound sometimes mixing in a triangle wave one octave below the main oscillator at 50-75% volume will add more apparent low end punch to a sound than if you ran it at 100% volume. Remember-the trick to achieving good bass sounds is NOT the amount of low frequencies in your sound, but the impact that the sound has overall; many sounds may, on an oscillascope, contain far more low frequencies than another but not sound as strong. Let your ears and common sense be the guide.
Another fallacy of analog synth programming is that the more oscillators the fatter and deeper the tone. This is simply false. While having additional oscillators offers more versatility in sound and tone setup, many times these additional oscillators will introduce phase cancellation which will weaken the overall sound. Case in point, one of the most famous synthesizers for producing good, solid bass sounds is the Juno 60 or Juno 106-both of which are single oscillator DCO analog synthesizers (with a square wave sub-oscillator); although the Junos clearly lack oscillator power compared to an Oberheim Four Voice or a Korg Mono/Poly, the Juno’s are considered to be superior to both for producing bass tones in many types of music. Another thing to consider is this: the vast majority of analog synthesizers are of the dual oscillator variety-but, just becuase you can use two oscillators DOESN’T MEAN YOU ALWAYS SHOULD! There are a lot of “single oscillator” type bass sounds that are superior to multiple oscillator configurations; don’t restrict yourself to using everything that is available to you. Generally speaking, a properly created single oscillator bass sound tends to be punchier and truer in pitch than a dual or great oscillator bass patch.
Roland Juno 60: Well respected in many different circles for its wide range of deep, punchy bass. Part of the Juno 60′s appeal may be its simplicity, which makes committing many bass programming errors impossible.
Another misconception about bass sounds is that you should automatically set the oscillators frequency very low-to 16′ or even 32′ ranges. However, this makes many of the important frequencies inaudible to the human ear and weakens the fundemental harmonic of the sound. Generally speaking, you want at least one of your oscillators pitched to the 8′ range or higher; you may choose to mix this oscillator’s volume down somewhat to reduce the brightness of the sound. For single oscillator synthesizers this may seem somewhat depressing, but generally it is a good rule to stick to, especially if the synth has a sub-oscillator onboard such as on a Juno or Korg Polysix. For simpler synths, such as a Micromoog, it is permissible to set the oscillator lower if you choose; however, you will lose some brightness and punch to the sound.
Finally, there’s the subject of monophonic synths versus polyphonic synths for bass sounds. Many believe that monophonic synths produce a “purer” tone than polyphonic synths, especially when the polysynth has been set to unison mode. There is a strong possibility that this is true, due to the effects of phase cancellation in the signal due to multiple voices playing in unison in a polysynth; the monosynth would be unhampered by this and thus produce a clearer fundemental pitch. My suggestion for dealing with this is to make sure to detune your oscillators slightly to compensate for this fact. Also, monosynths tend to be more affordable than polyphonic synthesizers, and since most bass lines are single notes, the additional polyphony is somewhat “lost” in the process. However, both polysynths and monosynths are capable of producing good bass sounds if they are set correctly-which is the purpose of this article.
Moog Minimoog: Widely considered one of the best synthesizers of all time, the Minimoog produces a fat, chunky and wooden tone unlike any other synthesizer before or since.
Once you have set your oscillators to the proper frequency and mixed them at a pleasing volume level, it is time to move on to the next stage of analog synthesis-the filter. Without fail, the filter type of choice for bass sounds should be a low pass filter of either the 2 pole/12db or 4 pole/24db variety. While there is a lot of debate about which manufacturer’s filters sound better, generally speaking all low pass filters are capable of producing decent bass sounds if they are set correctly.
Another misconception about programming analog bass sounds is that the filter cutoff should be at a very low frequency in order to produce a bass tone. This is not always true. What the filter does is to color the sound and set the apparent brightness of the sound more than determine the “bassiness” of the patch. In fact, by setting the frequency cutoff too low you can obscure the fundemental frequency and greatly weaken the impact of your sound-and completely undermine the solidity of your song.
A tricky part of analog bass programming is setting the filter envelope to modulate the cutoff frequency correctly. Remember that the effect of the “filter amount” to the envelope is governed by the cutoff frequency itself-if you set the cutoff frequency high and the filter envelope modulation high you will hit the filter’s “ceiling” and the result will be no apparent movement of the cutoff frequency. When setting the envelope amount to the filter you should carefully listen to how the cutoff frequency is being affected by this modulation.
One final word about filters concerns resonance, filter emphasis, or “Q” as Moog called it. High amounts of resonance can be destructive to the apparent loudness of bass frequencies located away from the cutoff point-this is because, if you recall, resonance governs the amount of boost that occurs at the cutoff point. Extremely high levels of resonance do not lower bass frequencies, instead, the low frequencies are overshadowed by the high peak at the cutoff frequency. Generally speaking, when programming bass sounds you want to use NO RESONANCE WHATSOEVER by default; if the sound you want contains resonance make sure to use it in small to moderate amounts. Either way, let your ears be the guide.
Oberheim OBXa: One of the few polysynths that can really compete with monosynths for producing thick, lush and deep bass sounds-among many other things.
The final aspect of analog bass programming are setting the amplitude (VCA) envelopes. The VCA (voltage controlled amplifier) governs the overall loudness of the synthesizer’s sound and is typically the final stage before a sound is outputed from the synth. Setting the envelopes correctly to produce the sound desired is often a tricky art that outfoxes most novice players.
One of the more hotly debated issues about envelopes is envelope speed. It is generally considered that fast, hardware produced, envelopes create a better sound than slower-typically software generated-envelopes. Much of why this is true has nothing to do with the bass frequency generating abilities of a synth; mostly, synths with fast envelopes produce more “punch” because they are able to quickly modulate the filter cutoff up and back down again (see filter envelope). This brief burst of high frequencies will fool the human ear into believing the ensuing tone is somewhat brighter and punchier. Additionally, this brief, often measured in less than 10 milliseconds, blast of higher frequencies will better define each note’s start-resulting in clearer sounds that sit well in a mix.
When setting amplitude envelopes, remember that in the real world sounds often build up quickly (attack) to a peak and then level off (decay) to a steady plateau (sustain) before finally fading away (release). This activity mimics the ADSR envelope in your synthesizer. Remember, the amplitude envelope governs how the synth sound’s loudness is effected when you play a note. By giving a sound a quick attack and quick decay that levels off to a moderate sustain level you have created a volume “spike” that will add punch and definition to your sound. Conversely, some bass sounds have no attack or decay-which is excellent for “organ” type sounds. One tip though: whenever setting sounds that have an attack period but no decay ALWAYS make sure to have the sustain level set at maximum, otherwise you will create an unnatural sounding drop in volume that can be annoying unless used specifically for effect.
One final tip about setting overall volume levels on your synthesizers: try to “normalize” the output volume level between your patches and make them the same apparent volume. Try not to use the master volume control to make adjustments-make them to the sounds themselves. Many times, for polyphonic synths that have unison mode, unison will be vastly louder than a corresponding polyphonic sound. Control the volume levels by setting the oscillators at a lower volume for unison sounds, or by setting the VCA sustain lower. Some synths, especially modern ones, have a “master volume” that can be set for each patch to allow you to normalize your levels accordingly.
As you can see, there are a lot of factors to consider when programming analog bass sounds. This article has only grazed the surface of the number of choices available for making bass sounds. Future articles will cover utilizing modulations to create unusual bass sounds, studio techniques for increasing the quality of your low end sounds, precise settings for achieving some of the more common bass sounds as well as detailed reviews of analog synths that are considered to be classic bass machines.
Until next time.
James Meeker
Pro AudioUnit and VST plugins
