Envelope follower allows you to take any output (any single PART, or all of the PARTs mixed, or the A/D input) and turn that into a virtual knob. If the PART or PARTs or A/D input are outputting lots of sonic energy ("loud" ), then the knob will be turned up. If the PARTs are silent - then the knob will be turned all the way down. And all points between. The virtual knob will turn in real time according to how loud or soft a PART or PARTs are.

https://www.youtube.com/watch?v=KQ2fAtTsB8I

Side chain is a parameter in some effects allowing modulation of the effect.

https://www.youtube.com/watch?v=KaBpB6XmFRY

You can take a look at how they are used and determine if there's a best fit for what you're doing.

Thanks Jason for your prompt response, it is very much appreciated. To be honest with you I have watched those 2 clips but could still not understand the differences, but will try again. It seems to me both response to the drum beat and play the arpeggio pattern as configured.

Kind regards

martin

Note that neither sets the tempo. That's done with MIDI Clock Sync set to A/D In.

Envelope follower uses source/destination pairs - part of the control matrix. Sidechain is a bit more fixed in what it does - and is not all in one uniform place.

Martin,
They (Envelope Follower and Side Chain) have similarities in that they create an influence that is applied to some other component (the energy of one is used to somehow influence the output result of something else) — one thing is used to influence another.

Follow this for a moment... take these two things, a microphone and a speaker. Seems like two completely different things. But they both are “transducers”... they take one form of energy and convert it to another. One is the opposite of the other. The microphone takes air molecules in motion and converts them into electrons; while the speaker takes electrons in motion and converts them to put air molecules in motion. Related but not the same.

Let’s take an Envelope Follower — the acoustic energy creates a quick Amplitude attack with a peak and sharp drop-off. The EKG that they use in the doctor’s office has sensors that listen for your heart beat... it get represented on a rolling piece of graph paper, shown as a spike peak and a sharp drop-off ... that graphic is “following” the “envelope” created by the energy of your heartbeat.

Substitute a kick drum for the heartbeat... it’s energy creates the envelope (shape of the energy), you can now use that rise in value and quick drop in value to open a filter, or to suddenly increase volume output, or suddenly Pan something from left-to-right. Each Hit would cause the target parameter to respond... to literally “follow” the “envelope” shape of the source.

Now, you can choose to hide the source... by this I mean, the audio of kick drum does not have to go to the output. Normally the kick drum sound is routed to the main output, but you can shut that output Off, and just feed the acoustic energy output to modify the target parameter. (Like with a Vocoder, you can choose to mix in your voice or just hear the Robot voice). Envelope Follower... the source creates the shape, the target follows that shape.

Side Chain
Side Chain is similar in that you are using energy from one thing to influence another, but there are many different ways to do this... here’s a typical example, again we’ll use a kick drum as the source... it’s pulsating hits are fed into (side chained means fed into) a Compressor that is assigned to a synth choir/pad sound. A Compressor is an amplifier that is able to turn down signal (compress the dynamic range) that exceeds a set value. A Compressor looks for loud spikes (peaks) and works against them ... holding back how loud they can go. So the Kick drum hits are fed into the synth choir/pad Part’s Compressor... but instead of compressing the Peaks of the kick hits, the energy is used to turn down the sustaining synth pad... so a long held chord would dip quickly in volume each time the kick drum hits. Creating a pulsing, dynamic drop in volume every time the Kick Drum is hit... this action is called “ducking”. The pad sound “ducks” down every time the Kick’s energy is side chained into the Pad’s Compressor. Again you can choose to listen to the source or not.

Envelope - describes the shape of change (Attack-Decay-Sustain-Release)
Follower - the Part asked to Follow changes according to the envelope of the source.
Side Chain - an influencing source is additionally plugged into another Part’s Insertion Effect — the energy of that incoming signal is used to change something about the result.

A Vocoder is very much apart of this same discussion ... the noise you make in front of a microphone can be use to influence the sound you are playing on the keyboard. Pitch can be applied by the keyboard sound. In general, the sustaining vowel sounds are provided by the synth and keys that you trigger, the artful noises that make speech intelligible (consonants) are applied via the mic to the synth sound. When humans sing, we can only really apply pitch to vowel sounds... but instead of you providing pitch to those vowel sounds, the synth supplies the pitch...
if you sing the word “smooth” it is the vowel sound “ooo” that you can give pitch
If you sing the word “sweet” it is the vowel sound “eee” that you give pitch
The “sss” that starts both words will be the same fixed pitch, no matter how far apart the notes. You can’t give ssss Sound any significantly different Pitch... it’s what is referred to as a fixed frequency component. Consonants are artful noise, mostly fixed frequency components that when used together turn the vowels sounds into intelligent words... the more noise (random frequencies) allowed, the more intelligible the Vocoder). You need high frequency noise to tell “try” from “bye”...

A Vocoder encodes your vocal onto the synth sound... Any audio source can feed the Vocoder, meaning the pitch you play can be applied to any type of input.

Thank you for your replies Jason and Bad Mister, it is something new for me to learn as I watched the videos Jason posted many times before I asked the question here because I could not see the difference. They both were very similar to me, basically I have some of the sound with the arpeggio pattern which I like and these sound have internal drum beat, so what I want is instead of responding the internal drum the arpeggio would response to our drummer beat, I know how to set them up either envelop follower or sidechain, but I was a bit confused of which one would be best to use and effective in a live environment and why it is correct to choose that option. Obviously I know how to switch the drum beat off.

Thanks

Martin

The differences can be subtle (somewhat of a sliding scale). There are times when they are the same thing. One is sort of a subset of the other. Maybe an analogy would help.

There's also other concepts in Montage that are similarly closely related - and maybe referring to these you can connect some dots.

"Envelope Follower" is a SOURCE in the Modulation Control Assignments. Modulation Control Assignments have lots of possible sources - "Envelope Follower" is one of these types of sources. The screen to edit the assignments looks like this:

The DESTINATION for "Envelope Follower" can be programmed to be any of a hundred or so parameters. There's lots of flexibility with Modulation Control Assignments - so it's good that "Envelope Follower" is something you can assign as a source.

The analogy I'm going to use is "loose" because I'm going to switch contexts to DESTINATIONs (not sources) - but I think you can connect the dots.

In the Modulation Control Assignment system, I can select "Part Volume" as a DESTINATION. This is one of the things that "Part Volume" as a concept can do. We connect this with a source - and the source can be any of 40 or so controllers (assignable knobs, ribbon, aftertouch, MS lanes, etc). This is a very flexible system since curves can relate the controller to the "Part Volume" and these curves are numerous in defaults and also parameter options - as well as having two types of user curves to "draw" on your own. NOW - there's also another "thing" that can control Part Volume - that isn't part of the Modulation Control Assignment system. That's LFOs. LFOs can have Part Volume as a "destination" (an LFO can control Part Volume). The Part LFO is more limited in the number of "curves" (waveforms) it can do - it's slightly more "fixed" in how it works. Analogous to side chain. However, if you setup the Modulation Control Assignment system to use an MS Lane of a certain type - this Modulation Control Assignment version of "Part Volume" can be the exact same result as the LFO version of "Part Volume". Are they the same (Modulation Control Assignment and LFO)? No. But there is overlap. They CAN be the exact same under one type of programming. But they diverge in others. The primary differences are:

1) Where you go to edit an LFO vs. Modulation Control Assignments. The screens are different. You click different buttons to end up in each spot.
2) The amount of flexibility. Modulation Control Assignments (which Envelope Follower is a part of, as a source; as well as "Part Volume" as a destination) is more flexible with more options. LFOs (like side chain) is a bit more fixed. Yes, there is flexibility - just less knobs to turn and less options.
3) Resources - Modulation Control Assignments have their own resource pool. You get 16 destinations per PART. Using this method for a single assignment takes away 1/16th of your resources. The LFO does not use this resource. Sure - you only have a finite number of destinations for LFOs and only so many of them. The point is they are different pools - so they diverge in this way. Using one does not consume resources of the other even though they can target the same result.
4) Jumping away from the analogy - and back to "Envelope Follower vs Sidechain" - Envelope Follower - since it's part of the Modulation Control Assignment system - all happens in the framework of the screenshot attached to this message (above). Sidechain has many different places to go since sidechain is a piece/option in some effects. Each of these effects has a different screen and is generally less uniform to relate to due to this difference. How you program sidechain is not part of a uniform "system" like envelope follower is.

Since there is so much overlap - you're right to think they're "the same". At least in a way. There are times when they absolutely are the same thing. You can create ducking when the A/D input bass drum strikes with envelope follower and get just about the same result as a sidechain counterpart. There are things you can accomplish with envelope follower you just can't do with sidechain. Vice versa as well. Mostly, it's easier to see how the flexibility of control assignments allows for more flexibility - and the additional layer of many curve types and parameters to change the relationship of a controller (source) to a parameter (destination).