Direct effect inserts vs. aux effect sends

[Master Mi]

I got into a pretty interesting topic concerning mixing lately.

There's obviously a big difference between using integrated VSTi effects and insert effects (blend original signal and effect together into a new sound) and using AUX/effect sends (adds an additional signal like just the reverb on a separate AUX bus track to the original signal).

https://l2pnet.com/insert-effects-vs-send-effects-2/

1) Integrated VSTi effects and insert effects
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For my tracks I was used to create some MIDI stuff, add a virtual instrument or synthesizer for this track and mostly use some VSTi-integrated reverb and delay effects or some external reverb and delay VST plugin effects as an separate insert on the VST plugin slots within this track.

The problem with this combination is that the original & pure sound of the VSTi/synthesizer loses its former power and blends together with the reverb/delay effects (although the reverb might be the most problematic effect in this case) into a new (and in this case less powerful, less assertive) sound.
So, it 's not like "instrument + effect" - it 's much more like "instrument * effect" or "instrument x effect".

With my new 3-way studio speaker system I can perceive this issue much clearer than before and I notice much better if the sound of an instrument or synthesizer gets too thin, gets lost in the reverb or shifts too much into the backround/depth of the room.

It's not that you can't do it this way if you want to use some reverb in your tracks - but it doesn't seem to be the very best way of creating clean, assertive mixes on a professional production level.
Nevertheless using reverb as an insert effect could be useful if you want to create a more spatial offset in depth in your soundtrack.

However, it's a bit strange that I haven't got into the obviously very important topic of using AUX/effect sends for creating reverberating and highly assertive sounds at the same time - until now, after almost 5 years of music production.
But after looking up a few things in my DAW manual some time ago I stumbled over this topic and tried it out.

2) AUX/effect sends
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If you want to use AUX/effect sends you have to create a new separate AUX bus track (like if you want to create an additional MIDI track in your mix - but instead you choose to create an additional AUX bus).
On this AUX bus track you only use the desired effect (or even more than one effect at once - let's take a good reverb effect in this case) in one of the plugin slots and set up the plugin in the way you want to use it in your soundtrack.
Several producers recommend to set up the plugin of the AUX track 100 % wet because the drier the effect gets the more it will mostly raise just the volume within the combinated interaction of VSTi/synthesizer and effect sends.

Now you choose the track with the instrument or synthesizer with which you want to connect the AUX/effect send and try to set up the instrument as pure and raw as possible (especially turn off all reverb and delay effects, additional VST plugins and everything that makes the VSTi/synthesizer sound thinner, less assertive or moves the raw sound out into the room).
Then you open your mixer and look for this instrument track, look for "AUX" within this instrument track and there you choose/activate the prepared AUX track with the desired effect in one of the free AUX slots.
In my DAW I can draw a bar with my mouse below each of the AUX slots within the instrument tracks in the mixer view where you can regulate the volume of the additional effect send (don't worry about the volume of the instrument track, it makes no changes there  - it just controls the volume of the effect sends on the AUX bus track there).

So, if you play just the instrument track in solo mode afterwards you will hear the raw, unprocessed and highly assertive instrument sound.
And if you play just the AUX bus track in solo mode you will just hear the separate effect of the instrument (so, just the reverb in this case).
(If you turn up this AUX send effect on other instrument tracks in the mixer as well you will hear different effects (reverb from different instruments in this case) on the same AUX bus track.)

With this method you can create really strong reverb effects without loosing the power and assertiveness of the raw source instrument/synthesizer.

I am not quite sure how I should handle the panorama setting at the AUX bus track - I guess it would make sense to pan it the same way like the instrument.
Maybe you can be a little creative there (for example if the reverb effects of two intruments who are pretty close in the mix interfere too much with each other you could take the reverb effect sends of one instrument more to the left/right side).

If you plan to use an AUX/effect send on more than one instrument at the same time it could be problematic to deal with effects from different instruments at one AUX bus track with the same panorama.
On the other side it will be pretty effortful, confusing and CPU/DSP-intensive to create individual AUX/effect sends for each instrument/MIDI track.
And as it seems I can only put 10 different AUX/effect sends in the slots of the instrument tracks in my mixer.
So, it might be useful to take the AUX/effect sends just for some instruments who really have to shine with effects (like reverb in this case) and be highly assertive at the same time (for example drums or leads).
(EDIT: I could manage to create an infinite number of AUX/effect sends in my project within my DAW settings - so, technically I could create an effect send for each instrument/MIDI track.)

What is your opinion about this topic and what kind of experiences do you have made with this?

Edited January 11 by Master Mi

[Jorito]

I use sends most of the time, for a few reasons. Apart from saving some CPU power, it also helps to glue the sound together (in the case of reverb and delay) when you send all your instruments to the same reverb sends. More importantly, using a send means you can process just the effect. A very common and incredibly useful thing is to EQ the reverb to get rid of some mud. I usually put an EQ after the reverb and cut out everything below 200Hz to prevent a messy sound, and sometimes I also high shelf it to prevent it from sounding thin. Optionally you could also choose to EQ the sound before it gets to the reverb, to remove some nasty frequencies.

What I wouldn't do is to use a different AUX/bus for every single instrument, that's not very useful. Just stick to a limited set of sends and use those for all instruments, I'd say. Personally I use 3 reverb busses (one for early reflections, one with a plate reverb and one with a hall reverb) and 1 bus for delay, which I use for almost all of my tracks. For the few times I have an instrument that needs some dedicated processing (e.g. a fancy delay or a long shimmer reverb), I typically add those directly as an insert effect.

I usually leave the pan of the sends at 0, but a nice trick is to put a widener (e.g. with the Ozone Imager) on just the reverb so only the reverb gets widened, which makes for a subtle but enjoyable effect.

Last but not least, I don't bother switching off the effects in the VSTs/synths. I might tone down the effects a bit if it's too much, but I usually leave them as-is and apply my reverb busses to it. When working with orchestral samples, these tend to be all over the place. Some of them are very wet, some of them very dry, some of them in between. For a homogenous sound I usually end up applying some reverb on the master bus to put them all in the same space. That trick might work for your instruments too, but for synth sounds I usually don't bother and just stick to my regular busses. 

[Yoozer]

When do you use inserts: for distortion, EQ, compression, chorus, flanger, phaser.

When do you use sends: for reverb, delay.

When are there exceptions: any time you want 'm. You can use compression as a send effect to get something called parallel compression.

These are rules of thumb, and rules can and should be broken if you learn something from them.

Chorus (or plain old oscillator detuning) can make the sound wider, but at the same time it can get weaker, because it's cancelling itself out in terms of phase. Reverb lets a focused sound compete with a smeared copy of itself; naturally, when the copy gets stronger, the sound is less focused. You camouflage the transients.

In the end, all you're doing is controlling the ratio of dry and wet. Send effects aren't "better" in this regard. It's just that you start with 100% dry and sum a wet signal on top of that. Let's say you have 100% dry and 20% send; the total is 120%. 100% is 100/120*100 = 83% of that, so the signal is 100 - 83 = 17% wet.

This is effectively not different from using an insert effect and setting the wet/dry to 17% wet. The difference comes in once you start adding other tracks, because then you get something you can't do with insert effects. The other difference is that 20% on an insert is not the same as 20% on an aux send, so you'll indeed hear more of the dry signal.

"You have too much reverb" is an oft-heard complaint. Reverb is like MSG for the sound; it makes everything better. However, you usually don't notice that you're using too much of it.

You can use a reverb as an insert effect. The downside is that if you have two tracks and you use two distinct reverbs, it sounds pretty unrealistic; you can't have one instrument sounding like it was recorded in a small tiled room and another in a concert hall. That ruins the illusion. If you use exactly the same reverbs, they may still mismatch, because the result of two dry instruments playing in the same room is not identical to summing two instruments each playing in their own room.

What aux does, effectively, is that it creates a submix. Let's say you have a dry mix of guitar, bass and drums. Drums are set to 100% volume. Guitar is set to 60%, bass to 80%. That is the mix that you hear.

With auxes, you can make the mix completely different; on an aux you create a duplicate of the mix that may be set to guitar 100%, bass 40%, drums 20%. That is the duplicate mix that you send to an effect (any kind of effect). The effect will "hear" that mix completely different from how you're hearing it. The end result is sent back to the mixer as if it were a single stereo track, and summed with the original. If you're using a reverb effect, the guitar's wet/dry mix may be a lot stronger than that of the drums, but since everything is still in the same "room", it'll do more to suggest positioning (i.e. how close to the microphone was the instrument). Panning is in that sense not different from any effect.

Experiment! Keep things simple initially; just a few tracks. Try all combinations. You'll learn a lot.

[AngelCityOutlaw]

Time-based effects, or anything which is supposed to affect a group of instruments is a send.

Individual effects, if used at all, are inserts.

[DarkEco]

2 hours ago, Jorito said:

Personally I use 3 reverb busses (one for early reflections, one with a plate reverb and one with a hall reverb)

@Jorito I'm interested in hearing more about this technique. I recently experimented with setting up 3 reverbs of the same type to handle near, mid and far (far having the longest decay) and sending the instruments to their appropriate reverb depending on where i wanted them spacially. I'm not really sure it worked as intended and i ended up scrapping the idea earlier this evening, but it sounds like your technique is much the same thing except using completely different reverbs on each bus? So do you send your instruments to only some of the reverbs or are your busses intended to act as a layered single reverb unit that all instruments will go through? And how messy does having multiple reverb types end up getting?

[Nabeel Ansari]

Sends are for groups of signals going through one effect chain. It saves a lot of CPU compared to loading effects units on individual channels (and came about because with hardware, you physically can not duplicate a $3000 rack gear reverb on like 50 tracks). Additionally with send levels, it's pretty easy to control how much of each signal goes through the effect, and additionally if it is pre-fader (absolute send, no matter what the volume fader of the track is) or post-fader (the track volume directly scales what is sent to the send).

Yoozer pointed out several use cases of sends. It's really just a better way to work and allows more mixing possibilities than sticking to inserts does. It's literally less effort to manage 1 (or a few if you're experienced) reverb send and just controlling what's going through it. You get a 100% wet signal in the send track and can do stuff to it, like EQing or filtering it, adjusting the *entire* reverb level of the song all at once on one fader, applying mid/side techniques if you're into that, and more. The consistency afforded by routing all of your tracks into just a few plugins creates much better mixes, much more easily.

[Jorito]

8 hours ago, DarkEco said:

@Jorito I'm interested in hearing more about this technique. I recently experimented with setting up 3 reverbs of the same type to handle near, mid and far (far having the longest decay) and sending the instruments to their appropriate reverb depending on where i wanted them spacially. I'm not really sure it worked as intended and i ended up scrapping the idea earlier this evening, but it sounds like your technique is much the same thing except using completely different reverbs on each bus? So do you send your instruments to only some of the reverbs or are your busses intended to act as a layered single reverb unit that all instruments will go through? And how messy does having multiple reverb types end up getting?

Basically I just use the methodology explained in https://www.puremix.net/video/creating-space-with-reverbs.html (it's a paid thingie):

1 - One reverb with just early reflections. Typically I use this mostly for live recordings (that usually are close mic'ed) to give them a bit of distance from the mic. It can sometimes also be handy to phatten up a tone at times, but it's primarily in use for recordings.

2 - A plate reverb that's typically used to create distance. I use this one on most of the instruments, with varying send levels.

3 - A hall reverb for 'height'. Typically I only use this for lead instruments and sometimes for snares and claps.

Not quite the same setup as I use, but more or less based on the same concepts and it's free, so this might be useful:

It's a setup I've been working with for close to 2 years now, it works for me and essentially I have 3 preset channel strips for it now where I sometimes just change the reverb to a different preset. Otherwise I just call it a day and move on.

As for getting messy with multiple reverbs, not really. If you apply things subtly and smartly (and very important, EQ the reverbs!), it'll sound fine (IMO). Here's just an example of a sparser track I did with this setup: 

 

[Master Mi]

Thanks for the detailed feedback and many practical hints. ))
(EDIT: I could manage to create an infinite number of AUX/effect sends in my project within my DAW settings - so, technically I could create an effect send for each instrument/MIDI track.)

But you would say that just for the sound quality it makes no big difference if you use reverb as an insert or use it as an AUX/effect send?
It's because I got the impression that if you use an reverb insert on an instrument the sound of this combination gets more into the background or sounds farer away in my speaker.
If I use reverb as an effect send the unprocessed original source instrument stays totally in the front (sounds close and assertive) while just the reverb goes into the back of the room.

Maybe it's just an illusion shaped by an unequal mixing ratio between the wet and dry components of the effect send - compared to the reverb settings an insert.
But I'm not quite sure about this.

[Jorito]

If you use sends, you typically set the dry to 0 and the wet to 100% and use the send level to control the balance.

I have the impression you’re looking at this from the perspective of a single instrument. When mixing, it’s important to look at the track and balance as a whole. And trust me, I’d rather have 3 reverb sends where I can control the send levels directly from the mixer, rather than having 60 insert effects where I’d have to open the vst or automation lane to control the balance.

Make it easy for yourself, save some cpu and look at it from the perspective of mixing a complete track. $0.02.

[Yoozer]

8 hours ago, Master Mi said:

But you would say that just for the sound quality it makes no big difference if you use reverb as an insert or use it as an AUX/effect send?

If you have two instruments and both give 'm separate reverbs, it's just going to sound unnatural. "Sound quality" is a weird way to describe it; it's more of a "this is something you can't ever hear naturally". Mixing is about the suspension of disbelief, and unless you're live-recording an orchestra with a pair of microphones separated at a distance equal to your ears in a seat somewhere in the venue (which is -still- an approximation because your ears work different from microphones), you're always trying to "stylize" things to paint a scene, send a message, or perform illusionism. It's like a render of a scene; your eyes don't focus on two distant things at the same time and adapt continuously to the light around us (and fill out a hilarious amount of details outside of your focal point that aren't really witnessed - just painted in there by your brain).

8 hours ago, Master Mi said:

It's because I got the impression that if you use an reverb insert on an instrument the sound of this combination gets more into the background or sounds farer away in my speaker.
If I use reverb as an effect send the unprocessed original source instrument stays totally in the front (sounds close and assertive) while just the reverb goes into the back of the room.

With inserts, you're actively decreasing the volume of the dry signal while increasing the volume of the dry signal. It's a crossfader.

With sends, you keep the dry signal at equal volume while adding more wet signal - and as Jorito says, you should have the wet to 100%. It's two separate faders.

It's about the ratio of the mix plus multipliers. With inserts set to 20% wet, it means the dry signal is multiplied in volume by 100% - 20% = 80% (0.8) while the wet signal is at 20%. With a single wet/dry knob, you can't have a scenario where dry is 90% and wet is 40% or something - the sum always has to be 100%.

With sends, the dry signal is left at 100%, the wet signal at 20% - the sum of this (120%) is the "new" 100%, and if you'd scale everything back proportionally (100/120 = 0.83), it's comparable to the insert's dry/wet as 83%/17% in terms of ratio, but both are louder.

[Master Mi]

So, you would say you can achieve similar results with reverb inserts and reverb sends in the end - but reverb sends allow a much more accurate mixing between dry and wet signal parts?

Okay, so I don't have to rework all my tracks and remixes just because of this.
I guess I'll keep it this way (at least for most purposes like just creating reverb and delay for an instrument without anything else) because AUX sends tend to consume much more CPU/DSP at my DAW in hybrid engine mode where I can use all the functions to the maximum.
For example - with inserts at a complex track with some high-end plugins the DSP may go up to 70 % (at a normal remix with around 14 tracks and moderate plugins it might just be around 30 %) - but if I want to use just one AUX send the DSP can go up easily beyond the 100 % mark and create ASIO buffer problems (even with the highest ASIO buffer size of 2048 samples).

I don't know what's the cause of this problem - but that's one reason I'll mostly stay with the inserts.

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Some other points why I use sligthly different reverbs in tracks are following things:

1) Every reverb/delay of each type of instrument spreads a bit differently in one same room - so, the reverb/delay of a metallic instrument like a saxophon won't be exactly the same like the reverb/delay of a wooden flute or a contrabass.
2) With the help of different reverbs you can create a nice depth staggering (the impression that some instruments play more in the front of the room or stage while other instruments play more in the back/far away).
3) In most cases it doesn't make sense to use lots of reverb in the bass for example as if you do it for other parts of a track like clean guitar guitar melodies. As long as the bass has not an outstanding solo part in the track you rather want to make the bass as tight as possible that it won't bleed into other low frequencies too much.


 
 

[Jorito]

Quote

So, you would say you can achieve similar results with reverb inserts and reverb sends in the end - but reverb sends allow a much more accurate mixing between dry and wet signal parts?

Yes. Maybe not more accurate (equally, I'd say), but definitely easier to do and easier on the CPU. Also, keep in mind we're working in a virtual space and probably also with virtual instruments, so aiming for accurate, realistic reverb seems ... well... pointless to me. I'd go for making it sound good over making it sound realistic any day.

Quote

1) Every reverb/delay of each type of instrument spreads a bit differently in one same room - so, the reverb/delay of a metallic instrument like a saxophon won't be exactly the same like the reverb/delay of a wooden flute or a contrabass.

2) With the help of different reverbs you can create a nice depth staggering (the impression that some instruments play more in the front of the room or stage while other instruments play more in the back/far away)

If you're looking at the effect of timbre and reverb, I'd say you're better off using proper gains (further back = less loud) and EQ (further back = less highs, less lows) than minutely tweaking your reverb insert to have a 0.1 change in early reflections or pre-delay. Sure, reverb would help in creating distance, but I'd go as far as to say that using the right volume levels and proper EQ-ing the instruments properly will help you more.

Quote

3) In most cases it doesn't make sense to use lots of reverb in the bass for example as if you do it for other parts of a track like clean guitar guitar melodies. As long as the bass has not an outstanding solo part in the track you rather want to make the bass as tight as possible that it won't bleed into other low frequencies too much.

I hardly ever add reverb to my bass or kick. IF I do, it's a subtle bit of my early reflections bus and maybe a bit of my plate bus. Also, I know I'm starting to sound like a broken record, EQ your reverbs (which you can't do if you use it as an insert...) and simply cut off the low freqs there (I usually high pass at around 200hz).

Anyway, since you seem to be dead set on sticking with multiple inserts for your reverbs and you seem to be happy with the results, I will leave it at this.

[Master Mi]

It's not that I don't want to use AUX/effect sends at all - they offer indeed pretty nice possibilities for further sound design I would definitely use for certain tracks.
But before I have to find out why AUX sends in some of my soundtracks within my DAW tend to use up much more of the CPU/DSP unit than mere inserts.

At least it's good to know that you can use inserts for reverb as well if you don't want to edit the reverb separately.

[Master Mi]

After a long time, I finally found out why aux effect sends such as aux reverb sends in my DAW regularly pushed the DSP (digital signal processor - the internal CPU of my DAW, so to speak) in my DAW Samplitude to its limits, including dropout-related scratching noises (although they should actually require fewer computer and program resources compared to direct effect inserts) and I simply couldn't really work with the aux reverb sends (which are extremely important for a clean mix).

It was solely due to a general setting in my DAW, namely the setting that determines how many processor cores your DAW should have available.
I had set 8 cores at the time - but my Intel Core i7-6700 processor system only has a maximum of 4 cores (I had probably confused the number of cores with the number of threads).

In any case, after I had fixed the problem purely by chance at some point by changing this setting, the aux effect sends suddenly worked perfectly, stably and with a much more efficient use of the ressources related to the DSP.

...

Maybe this can also help somebody else.

So, if anybody has some trouble like this in its DAW, make sure to check all the program settings.
Just one single setting like this can make a huge difference.

...

This thread can actually be closed.

The main topic of this thread will be continued on a larger scale in the thread "Cleaning up the low-end und low-mid sections in a mix - with single track EQ, master track EQ, EQed aux effect sends and other methods" - a thread you can find much faster with the help of this link: https://ocremix.org/community/topic/52614-cleaning-up-the-low-end-und-low-mid-sections-in-a-mix-with-single-track-eq-master-track-eq-eqed-aux-effect-sends-and-other-methods/ ...

In this new thread I also provide (and still will provide) some (further) audio samples in order to show how the mixing quality improved after finally (and primarily) using separate aux reverb send channels for the instruments/source signal tracks (where you can especially change just the reverb with things like EQ/low-cut-filter, different pannings and other stuff - but without touching/changing the sound of the instrument source signal) instead of using direct reverb effect inserts in the plugin slots of your instrument tracks (where the instrument and the effect/reverb get processed together alongside the order of the inserts in the plugin slots).

 

[timaeus222]

Closed the thread as per request of the OP.