This month we are concentrating on bass sounds. This is an increasingly important area of the synth players 'vocabulary', especially in bands where there is no bass guitar player. Not only can it be tricky for a keyboard player to think 'bass-line', but satisfactory programming of a suitable sound can be very demanding. The reason for this is that when a sound is played in low register, virtually all the harmonics are in the audible frequencies (at higher registers the human ear cannot hear them), and so we can hear everything that is (or isn't) going on. You will all have noticed that a good sound taken down a few octaves can begin to sound thin and lacklustre. The reason for this is often that when the sound was programmed, the higher harmonics (then inaudible) were not catered for.
So how can we set about making our bass sounds more interesting? Firstly, if we want more high harmonic content, we can open up the filter, either manually (using the Filter Cut-off Frequency Control) or automatically (using the Filter Envelope Amount Control). Of course, this all dependant on there being some high harmonics to listen to. This will depend on the basic waveforms selected. The best two source waveforms to have on the oscillators are sawtooth (ramp) wave or a pulse width-modulated wave (PWM as it is often referred to). On some synths this is available automatically, but on most you will have to program it by routing a slow LFO triangle wave to the Pulse Width of both oscillators once Pulse (or Square if pulse is not available) has been selected.
Here is an example of a beefy bass sound on the Prophet 600 using this technique:
Note the other techniques that have been used to 'fatten' up the sound: the two oscillators have been slightly detuned (using the Fine control on Osc B) and Unison Track has been selected. This causes all 12 oscillators to play the note struck on the keyboard, which now works monophonically, single-triggering, low note priority (just like the Mini-Moog, which is still the standard bass-line synth for many people).
This patch also shows the usefulness of a 2ADSR synth. Here the Filter Envelope is being used to reduce the brightness (an effect exaggerated by the Resonance setting) more quickly than the volume (compare the two Decay settings), which gives the sound a more punchy percussion quality ideal for rhythmic patterns.
On this patch for the OB-8 by Oberheim demonstrator Todd McKinney, we can see some of the same techniques being used. Note the use of Page Two to bring in the LFO vibrato on oscillator 1 (Attack Mod 1 Control).
Of course, this patch can be tried on any of the Oberheim polysynths (OB-X or OB-Xa) as well, because of their 'family' similarity, and the only thing that will change is that the LFO mod will not be delayed. Try setting up this mod on the right hand lever instead, and then introduce it yourself after you have played the note.
Finally this month, we have help for those of you who are still struggling to program your DX7s with those old synth sounds. Here is a bass sound by Martyn Phillips (you may remember him from Java, our tape of the month in September). This is a hard 'syne'-type bass sound which makes use of the touch sensitivity of the keyboard to modify the pitch.
Source: Martyn Phillips
For those of you who still don't understand what's going on here, don't despair. Martyn is preparing an article for next month's issue which examines programming techniques on the DX7 in greater depth. In the meantime, keep sending us your patches, so we can cover the largest range of synths and the widest variety of sounds.
In this new feature we will be examining just how certain sounds can be created on particular synths. There are two reasons why we feel this to be useful. Firstly, no amount of in-depth synthesis theory, however thorough and well explained, can be applied completely to an individual make of synth. On modular systems it is perfectly possible to add more modules if your set-up doesn't cater for the required hardware (be it oscillators, filters or whatever) needed for a particular patch. But on a polysynth, if there is one oscillator too few or no filter envelope there is nothing you can do. So we have tied the patches down to particular synthesisers.
The second reason is that certain synths often have little peculiarities which can be made to do a particularly useful job in a certain sound and we will be endeavouring to highlight this where such idiosyncrasies exist.
We hope to use many sources to make this regular feature as widely reaching as possible, ranging from Factory presets and ideas from manufacturers, through sounds programmed by E&MM staff and regular contributors, to those submitted by you the reader. We also want to cover a wide range of synths be they brand new or old faithfuls. So if you have an unbelievable crumhorn patch for the DX-7, an authentic sax for the Wasp, or a sound no-one has ever heard before, send it through to us (in as comprehensible a form as possible) and mark your envelope 'Patchwork'. All sources will be credited, so here's your chance to appear alongside the big names!
As far as the patches are concerned, don't take them as gospel! Individual instruments of the same make and model number still vary from one to the next, so if the patch doesn't sound quite right, feel free to tweak the settings. No patch is unimprovable, however respected the source.
If you don't have access to the actual synth in any patch, this doesn't mean you can't try out this patch on a similar machine. As long as the basic format is the same, it should work. You never know it may actually sound better!
To set the ball rolling here is a look at how more authentic brass sounds can be created. We are beginning with a patch for the Poly 61 as the way this synth is programmed draws attention to every parameter and the role it plays in creating the final sound.
Gear in this article:
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