MODX reference manual, pg19-20:

The SYSTEM EFFECTS (Variation and Reverb) are shared effects – they are shared by all the Parts together. They provide the outer environment for the sound. That is, the room acoustics. Reverb is the size and shape of the room in which the instrument is played. The Variation processor can be thought of as mainly "time delay" effects. Its principal function is from extremely short time delays (Flanging and Chorusing) to long multiple repeat delays (like Echoes).

When a Single PART is ”merged” into an ensemble (Multi Part PERFORMANCE program) typically, the two Part Insertion Effects are brought along (Insertion Effects are treated as apart of the instrument sound I tself), but it does not take along the SYSTEM EFFECTS. And therefore the Part will not always sound the same as it does alone in a Single Part program. It’s outer environment when alone might be different from the acoustics where the ensemble gathers.
This is because the SYSTEM EFFECTS may, in fact, be very different selections. A small room when alone, a big hall when in the ensemble.

The SYSTEM Effects are shared by all of the PARTS. This makes sense because, remember, System Effects are the OUTER environment. It would be analogous to the musicians in an ensemble all being in the same room acoustics when assembled — but when HOME (alone) they have a different space.

You have an individual Send amount for each Part allowing you to place each instrument closer or farther away from the listener.

It works like each band member has their own two personal Effects (Insertion)*, and each instrument has a separate channel on the mixing console. Each channel on the mixing console has two Aux Sends — one to a Reverberation system, the other to a Time Delay. You, as mix engineer, get to send as little or as much from each Part to these “system” effects.
* a maximum of 12 MODX Parts can recall their Insertion Effects

The MASTER EFFECT is "post" (after) everything but the Master EQ. So they are applied to the overall (stereo) System signal. These are typically applied like "DJ"-type effects, for lack of a better term, because like a DJ would, they are applied to the entire recording. You may find certain Effect Types available as System, Insertion, and Master Effects — but it matters “where” they are assigned.

DJ's are either playing back a record or CD that is a finished mix. So the effects that they add are always post (after), they cannot put a Dynamic Filter on just the snare drum, if you get my meaning, so "DJ-style effects". Everything going to the Main L/R Outputs travels through the Master Effect, then the Master EQ.

DELAY LR
COMP DISTORTION DELAY
VCM COMPRESSOR 376
MULTI BAND COMP
UNIVERSAL COMPRESSOR DOWN UNIVERSAL COMPRESSOR UP PRESENCE
PARALLEL COMPRESSOR
LO-FI
BIT CRUSHER
RING MODULATOR
DYNAMIC FILTER
SPIRALIZER P
TEMPO SPIRALIZER P SPIRALIZER TYPE F
TEMPO SPIRALIZER F
ISOLATOR
SLICE
VINYL BREAK
BEAT REPEAT EVEN
BEAT REPEAT TRIPLET
BEAT REPEAT EVEN+TRIPLET BEAT REPEAT FREE
WAVE FOLDER
VCM MINI FILTER
VCM MINI BOOSTER

Significantly, these MasterEffects types are applied to the entire stereo SYSTEM signal. Don't be afraid to use your imagination with these Master Effects – some of them are quite radical. Things like putting a Delay on the final hit of the song so that it repeats and fades ...or using a frequency Isolator to roll out all the bass for a section of a song, then bringing it back in for dynamic impact ...or wacky panning effects with the Slice algorithm where you can pan signal left and right in tempo with the grooves; it’s even possible to mimic the sound of a manipulating a “vinyl break”. Also on the more normal side, you are given a powerful Multi-Band Compressor for pumping up the frequency bands of the final mix.

Thanks both 🙂 It makes sense to me now. I did do a word search for "system fx" in my pdf reader, page 19/20 didn't come up.

Search Suggestion:
System FX = NO
System Effect = YES

In general, the manuals tend to have enough room to use the entire term. After all, it’s function is to increase clarity.

When you see a block diagram graphic, as found on Page 3 of the MODX Reference Manual, “Basic Structure”, we highly recommend you take the time to study that diagram, closely — it really does give you an overview and a roadmap to cracking the “learning curve”. It shows how the various blocks are interconnected, and gives you direct links to where to get the information you require.

At first glance, it may be overwhelming, but as you start to expand your knowledge base, learning an area at a time, come back and refer to this graphic. It really does begin to help you “connect the dots” about how the various items relate to each other.

Hope that helps.

[quotePost id=115421]

I did do a word search for "system fx" in my pdf reader, page 19/20 didn't come up.

LOL! Been there, done that. No need to feel bad about that - it's one of those things where it all comes down to figuring out what to search for. I've also found that PDF searching can be buggy - sometimes it finds things and sometimes it gets hung up somewhere and can't find a second occurence of what it just got done finding.

Did you happen to notice that in the diagram on page 20 the box says 'System Effect'?

Just as a learning experience try searching for that and you will find SEVERAL references. Some of them include almost exactly what BM mentioned.

Page 3 - 'System Effects' in the Effects block of the diagram. And if I search again from there it doesn't find any more for some reason. I have to close PDF and open it again and now if finds more.

Page 9 and then on Page 19 -

System Effects are applied to the overall sound. With System Effects, the sound of each Part is sent to the effect according to the Effect Send Level for each Part. The processed sound (referred to as “wet”) is sent back to the mixer according to the Return Level, and output—after being mixed with the unprocessed “dry” sound. This instrument is equipped with Variation and Reverb as System Effects. In addition, you can set the Send Level from Variation to Reverb. This parameter is used to apply Reverb to the signals output from the Variation. You can get a natural effect by applying Reverb depth to the Variation sound with the same level as that of the dry sound.

Page 20 - the diagram already mentioned

Page 121 -

Dry Level (A/D Part Dry Level/Digital Part Dry Level)Determines the level of the A/D Part/Digital Part which has not been processed with the System Effect. This is available only when “Part Output” is set to “MainL&R.”Settings:0–127

Page 169

Page 209 - I think this is the one you found

Determines whether the System Effect is active or not.

I often have trouble with the PDF search mechanism and sometimes can't figure out the right search terms to use.

So don't beat yourself up if/when you can't find something (I'm not trying to do that either).

But you did things the smart way - try to find things yourself first - and then ask for help. I've found that is the BEST, and usually fastest, way to get the info you need.

[/quotePost]

Absolutely everything in the manuals is written backwards (from a pedagogical point of view) as if the writer is trying to impress an examiner by expressing knowledge known rather than transmitting it to those that don't via insights into concepts, paradigms and processes that's both impart understanding, enhance capability and promote discoverability.

This is a common problem. But these manuals do take it to a whole new level.

It doesn't help that BadMister keeps saying that once the manuals are understood they'll make sense. That's exactly the problem with them.

Docs could be better - but are very usable for this particular question. The table of contents first usage of the work "effect" is "Effect Block". When I hover over this, the pointer turns to a finger and clicking here brings you straight to the page where effects are explained. On that page system effects are defined.

I would say that searching for a specific term is best when you know the terms. When you don't know the terms - using table of contents and indexes (when available) are good starting points.

Also, although I do this less today, if you press alt-shift-F in Adobe (windows) and cmd-shift-F (Mac) - you can search for something less specific like "effect" (without the plural) which lists all places where the term is in the document WITH surrounding words. When I search for this, "System Effects" is displayed in the list on the first page of results.

Using table of contents to narrow down is faster and requires less guesswork.