Hello again,

its been awhile but I have a question.  How do a create that wobble bass effect like you hear in Dubstep music?  I have a video link I would like to direct you to watch so then you can explain how to do what he shows in the video with the MotifXS8.

thanks in advance,

ljmcdaniel32006

http://www.synthtopia.com/content/tag/wobble-bass-dubstep/

The answer is in two parts below ... hope you and others find it useful.

PART 1
You can start with any Voice you wish. On the Motif XS you have an LFO for each Element (that’s a total of 8 Element LFOs) and you have one COMMON LFO that can be routed to any combination of the 8 Elements via DESTINATION matrix.

Each Element’s LFO can be set to its own individual basic Wave shape: Triangle, Square, or Sawtooth
The destination for the LFO can be applied to “P Mod” (Pitch Modulation), “F Mod” (Filter Modulation), or “A Mod” (Amplitude Modulation). These three things Pitch, Filter and Amplitude are the three building blocks of emulating a sound. They are technical terms that can be translated to musical terms as follows:

Pitch Modulation via an LFO is what musicians call “vibrato” - a rhythmic variation of pitch up and back down.

Filter Modulation via an LFO is what musicians call “wah-wah” - a rhythmic variation of tone (think a trumpet player with a cup mute, or a harmonica player with their hand - the original wah-wah).

Amplitude Modulation via an LFO is what musicians call “tremolo” - a rhythmic variation of loudness

The video was correct in that a Low Frequency Oscillator was one that is not audible itself. Basically, the human ear recognizes sounds that oscillate (vibrate) between 20 times per second and 20,000 times per second. This is the audible frequency response of the human ear, measured in a unit called HERTZ. 20Hz to 20kHz. Anything higher than 20kHz, we say dogs can hear but we can’t. Pitches lower than 20 times per second, it’s not that we do not hear it, it is that we no longer recognize it in the same way. We start to hear it as separate distinct “events”. 

The lower you go in pitch you start to hear the sound break down to separate clicking events.

Call up the VOICE PRE3:086(F06) Dry Synth Bass
Hit the OCTAVE DOWN button 3 times. The top line will show you are down -3 Octaves.

Notice as you play lower and lower, starting from the highest note and going down the keyboard the sound starts to break down to separate clicks. You get to a point where you can actually count them as individual events.

Now reverse direction and start going up the keyboard again, there is a point at which you no longer hear individual clicks but they become a ‘blur’ of events and take on a different character.

The equivalent for the eye would be dots on a page that as you move left to right, keep getting closer and closer together, at some point the dots are so close together they seem to form a line. This is exactly what happens with the sound events… at some point the ear/brain “draws a line” and the events blur into a continuous note.

So LOW FREQUENCY OSCILATORS can be useful not as SOUND Sources but we can apply them as “RATES” - that is the point the video stops short of making. LFOs can used to modulate (change) something else in a rhythmic fashion - A Rate: like 3 times a second or 5 times a second.

We don’t hear 3 cycles a second as a musical tone - but we can use that as a rhythmic rate to modulate pitch, or modulate filter or modulate amplitude, etc… (The big three building blocks of this type of synthesis). In the COMMON LFO which we will play with below you can additional route the modulation (change) to any available Effect parameters, the Vocoder parameters, Filter Resonance, Pan position, and even modulate the LFO’s own speed.

PART 2

We are not sure how up on synthesis you are but we recommend you start simply with a single Element VOICE, because the complexity of what you can do with a synth like the XS is quite a bit more than can on today’s typical analog synth. This is not a statement about which is better - that has nothing to do with this, just simply having as many LFO’s as you do and the degree of programmability of those LFO’s on a synth like the XS is quite a bit more. (No it does not satisfy the audiophile purist, but it is a very, very decent compromise - because of all the other things we demand from a workstation synthesizer).

On the VOICE “Dry Synth Bass” press [EDIT]
Notice that on the right side buttons 1-8 will allow you to select ELEMENTS, while buttons 9-16 correspond to the ELEMENT’s status active or inactive. The button number 9 is lit = this means that this is a one Element VOICE and Element 1 is active

Press [COMMON EDIT]
Press [F5] COM LFO (Common LFO)
Press [SF1] WAVE
Highlight the Wave parameter and press [SF6] LIST
Here you have choice of 12 different preset waveforms, and an option to create your own shape “USER”

To start the experiment, select “TRIANGLE+”
This wave shape will allow you to move up from the center line and back to the center line… thus the plus symbol, you are moving up and back, rather than above and below.

Press [[SF2] SET
Here you will find the LFO DESTINATION ASSIGNMENT, There are three SETS. The first one is currently set to “P MOD”.

Move the cursor to the “ELEMENT SWITCH and DEPTH OFFSET” box #1
Place a red check there by pressing [INC/YES]
This will allow you to apply the LFO to Element 1 as a destination.

Move the cursor back to the CONTROL DEPTH and start dialing it up from 0 using the DATA WHEEL.

You will start to hear the Pitch Modulation - the higher you go the more pitch modulation.

Press [SF1] WAVE
Find the SPEED parameter and adjust it.

Experiment.....

Recognize that this VOICE is only a single Element.
Take a look at the various parameters you have, try them out… you can DELAY the start of the Pitch Modulation, you can have it Fade In, you can have it HOLD indefinitely or for a given amount of time, you can have it Fade Out, you can sync to the Motif XS clock (tempo) of the XS, you can adjust the phase (does it start a normal pitch and go up or does it start high and come down, etc., etc., etc.

While the synth engine in the XS is not an analog synth, per se, you can begin to see that it is designed with the accumulated knowledge of what types of controls were available in analog synthesizers that would cost thousands and thousands of dollars more.

I learned synthesis on a room-filling ARP 2500 (back-in-the-day) this was a giant modular synthesizer where to have 8 oscillators and 8 LFO’s, well lets just say was more money than I could have thought about spending at any time on a synthesizer. The cool thing about modular synthesizers were they were unlimited - if you had unlimited funds. While a lot of this is lost on folks today, I can remember how many modules it took to do just what I’ve shown you on these two screens with just the COMMON LFO.

Anyway that should get you started. Hope it helps.

thanks that helps tremendously

Yeah it does!! Thanks Bad_Mister!