The MOX6/MOX8 Drum Voice

What is a Drum Voice and how is it different from a Normal Voice?
A MOX6/MOX8 Drum Voice is an extra special Voice. If you are new to Yamaha synthesizer workstations, you may have never encountered a Voice architecture like this before. It is important to understand how this drum kit Voice works. Just as there are “normal” musicians and then there are Drummers, the Drum Voice is also very special case. Typically, a Normal Voice will consist of just a single instrument, like a Piano, a Guitar or a Flute, although sometimes you might find a combination VOICE like “Piano & Strings” or a String Ensemble or Horn Section. The Drum Kit Voice is actually a combination of up to 73 individual instruments. Each KEY, (C0~C6) in a Drum Kit Voice is an independent instrument. You most likely have never run into a drummer with a 73-piece kit! But that is just what you have here in the MO-X. Each key has a different drum or percussion instrument with its own set of parameters that you can manipulate.

A drum kit, in music history, is a 20th century invention first used in Jazz… called a “Trap Kit” (short for “contraption” – what someone called it when they saw how it was pieced together out of individual components). But prior to the jazz ‘trap kit’, drums were very much played individually and still are played individually in many instances. Think of a marching band. You have several people carrying single Bass drums, and even more carrying just a single snare. And some other who carry just a pair of cymbals… they are indeed individual instruments. And on Yamaha synthesizers the Drum Kit Voices is made up of 73 Elements. 

The way Yamaha constructs the Drum Kit Voice is so that you can place any drum and/or percussion instrument waveform into a Voice – typically each sample is on a separate KEY, between C0 – C6. Each KEY can have its own group of vertically stacked samples (when we say ‘vertical’ this is describing a velocity swap ). Each KEY has its own Volume, pan position, filter, envelope, EQ, routing to the Effects, Pitch Control, etc., etc.

A Drum Kit is like 73 VOICES combined in one. This allows you a great deal of flexibility when creating your music. Each KEY can be selected and edited individually. You can even assign your own favorite drums into your own USER KIT – there are 32 USER Drum Kit locations. This is useful when the snare you like is one kit and the kick you like is in another.

Drum Key edits and assignments are accomplished in VOICE mode.
• Press [EDIT]
• Press Track Select [1]
You will see “VOICE – KEY” in the upper left corner of the screen. Now when you touch a key on the keyboard, its information will come to the screen. There are five tabs available: [F1] Oscillator, [F2] Pitch, [F3] Filter, [F4] Amplitude, and [F6] EQ. We should mention that sometimes a particular drum or percussion instrument is mapped to several keys – each might be a different articulation or gesture used in playing that instrument. For example, the hi-hat is typically mapped to F#1, G#1 and A#1 (Closed, Pedal, and Open) – three different articulations of the hihat cymbals.

[F1] OSC (OSCILLATOR) – On these screens you’ll find the currently selected KEY, an Element ON/OFF Switch, the WAVE selection parameters (Bank, Category, Number), the Assign Mode (single/multi), Receive Note Off, Alternate Group, and the Effect routing.

[SF1] WAVE: Turning the “Element Switch” parameter to OFF will deactivate a drum KEY. This is where you select a Waveform by Category and Number for each KEY

[SF2] OUTPUT: This parameter determines if the Drum instrument is going to the kit’s assigned Insert Effect, or to the MIXING’s assigned SYSTEM Effects (Reverb and Chorus) or just THRU (neither). The Effect routing is per drum (KEY). A drum can be routed to the System Effects (Reverb and Chorus blocks) or it can be routed to one of two Insertion Effects selected for the kit. When a drum is routed via the Insertion Effect Output it is removed from the System Effects. When a drum is routed to an Insertion Effect it will arrive at the main drum kit output but it will have the Insertion Effect present.  Any two Insertion Effects can be assigned to a Drum Kit Voice. They are treated in “parallel” or routed from “A-to-B” or “B-to-A”. “Parallel” means each Insertion Effect is separated and a drum can go through one or the other. The “A-to-B” and “B-to-A” routings are what is called “in series” (one after the other).

• In the screen shot above we see a DRUM KIT Effect routing flow chart (from the MOX6/MOX8 Editor). The KEY OUT parameter in the upper left corner indicates we are looking a KEY “C1” (a Kick Drum) which is routed to INSERTION EFFECT B (blue) which is a “Classic Compressor”.

• In the screen shot above we see a DRUM KIT Effect routing flow chart (from the MOX6/MOX8 Editor). The KEY OUT parameter in the upper left corner indicates we are looking a KEY “D1” (a Snare Drum) which is routed to INSERTION EFFECT A (purple) which is an “Early Reflection”, then to the “Classic Compressor”.

Screenshots of the MOX EFFECT CONNECT (COMMON > [F6] EFFECT > [SF1] CONNECT) screen shows how each DRUM KEY (upper left corner) is routed through the Effects available. If a Drum Key is routed to one or the other of the INSERTION EFFECTS, it is automatically removed from the SYSTEM Effects and the SYSTEM Outputs (quite naturally). We say ‘quite naturally’ because you will be isolating those drum instruments and processing them separately from the general “pool” of other drums

To return to individual DRUM KEY Edit: Press the number [1] button to view KEY parameters.

[SF4] OTHER: Any KEYS placed in the same Alternate Group will replace the playback of any other. This is how the Closed High Hat, Pedal High Hat and the Open High Hat replace each other. And is how the Mute Triangle stops the Open Triangle. The “RcvNoteOff” (RECEIVE NOTE OFF) parameter is an important one to understand about drum sounds. You will notice that for most every drum sound this is set to OFF. This is what separates drum and percussion sounds from “normal” musical sounds. In a normal musical sound you hold the key down until you want the sound to stop and when you let go KEY-OFF is sent and the sound moves immediately to the RELEASE (time) parameter of the Envelope. Well with drum sounds you do not HOLD the key down. You want the entire drum to sound without having to keep your finger on the key.

In order to get a full understanding of this parameter, press note A2 (the “A” just below middle “C”) do the following: This will be a CRASH cymbal; set the RECEIVE NOTE OFF parameter ON. It now will behave like a regular keyboard sound… meaning as soon as you release the key the sound will stop. This can be useful in creating a “choke” cymbal. You can quickly see why drum and percussion sounds require this parameter – you do not want to have to hold down keys in order for the instrument to complete its sound ‘envelope’. The word envelope is used in synthesis to describe how something changes over time. In this case we are referring to amplitude or loudness – how the loudness changes over time.

[F2] PITCH – Coarse and Fine Tuning for each KEY; how the pitch of the drum responds to changes in velocity.

[F3] FILTER – Each Drum has it own filter. Basically a Low Pass Filter with programmable Cutoff, Resonance, Velocity sensitivity percentage and High Pass Cutoff parameter. Why a filter is important on synthesizers is to alter the fundamental tone (harmonic content) of a sound. In general, the more energy you put into playing (attacking) any acoustic instrument the richer it becomes in harmonics (see the article on EQUALIZATION for a discussion of harmonics). A Low Pass Filter, literally, allows the low frequencies to pass as long as they are below a particular “cutoff” point – this cutoff frequency is where the filter starts to attenuate (lessen) the loudness of certain harmonics. If you apply velocity sensitivity to a LPF, this means the harder you strike the key the more harmonics that will be allowed to pass… The faster a key goes down the higher the cutoff frequency moves – thus allowing a brighter, richer harmonic sound. This very much mimics what happens in the acoustic world. The harder you play the richer the tone. This is again, programmable per drum in a drum kit.

The High Pass Filter Cutoff frequency parameter allows high frequencies to pass and therefore attenuates lows. This is useful when you wish to remove low tones from a drum sound. As you increase this parameter you will reduce low frequencies in the sound assigned to this key.

[F4] AMP (AMPLITUDE) – Each Drum has its on amplitude envelope. Here you can also find PAN, ALTERNATE and RANDOM PAN options. Amplitude is how loud a sound gets and more specifically in the case of an envelope – how the loudness changes over time. All percussive instruments are hammered or struck in some fashion. This causes what is referred to as a “transient peak”. Simply put, a loud spike at the time of the attack, the sound then decays slightly and the body of the sound continues before it disappears completely. Think of a bass drum being struck by a mallet… now think of the whole process in extreme slow motion. There is the click of the mallet as it initially contacts the drumhead. There is a rapid spike in loudness, this is shortly followed by the booming response of the drum as the head starts to vibrate and is enhanced by the shell (shape) of the drum. CLICK → BOOM. The click is a peak, the boom is somewhat softer and somewhat later in time… and finally the sound disappears. That is what the ATTACK, DECAY1 and DECAY2 parameters are all about.

[F6] EQ – Each Drum has its own Equalizer. This device can be configured as a 2-band, single band Parametric or act as a straight level boost (+6dB, +12dB or +18dB).  Being able to equalize (balance the tone and loudness) of each individual drum is extremely useful in getting the exact sound you want from your drums. Use this equalizer when you want your KICK drum to boom or you want more snap from your snare. In other products you only have an overall equalizer (if you get that)… in the MOX you have individual equalizers for each Element… repeat – you have individual equalizer for each Element.

You may wonder why a 2-band and a single parametric EQ (instead of a three band, four band, five band or a graphic EQ)… The reason is it is assigned to a single drum sound. In any percussion sound there is the cause (the CLICK) and the response (the BOOM)… 2 bands is more than sufficient for a single drum sound. A single band parametric (parametric means you can zero in on a specific frequency, boost or cut and control how wide an umbrella above and below is affected) is perfect for Element equalizing when you need to fix a specific tonal region.