It could be one for the spec book of the particular desks in question.

When I run pre-fader I will run the send out at 100% on the chosen channel (sometimes having the FX outputs back onto another seperate channel rather than using the return bus). Would this 100% send value be lesser than the signal sent using an insert? Like I said that could vary depending on the desk (internal bus specs and stuff - way over my head really). Mmmm, have to look into that I rekon.

Still though, I do use the inserts where possible, but maybe I shouldn't be using the pre-fader send option as a quick fix?!

Na, no way Jase. You didn't come accross rude I rekon.

Maybe I'll talk to a mate in Ausi who has been producing bands occasionaly. He knows the ins and outs of desk set-ups really well (hehe, like my pun?).

And I will ask my lecturer........It will have alot to do with voltages and current I suspect, as does most of this audio stuff....

I think the thing is, although you are turning the aux send rotary 100%, the original signal is still being passed to the mix bus, through the fader. If you were using the inserts, that original signal would be diverted to the compressor, then back into the desk......and I think this is a standard setup regardless which manufacturer makes the desk.....

Interesting stuff.......

Great. Interesting thread this one!

Yeh that's what I meant by "could be something for the spec book" Maybe different manufacturers have different spec regarding the send busses.

Well...Let us know how you go with it Jase. Hopefully the lecturer doesn't blow up like last time hey. :wink:

Yes, but when you use the pre-fader aux at 100%, you can turn you fader all the way down to 0% and thereby only get the wet signal in through the aux-return (or another channel if you please). Then you will have removed the dry signal, that normally is routed through the fader (which is at 0 and nothing is getting through). The only thing you will hear is the signal that is passed to the aux-sends, further to the compressor and back through the aux-returns. If you turn down both aux-send and the fader, you get no sound at all. But I might agree with hollowcell that this could be desk-specific.

You can try to recreate it on you desk to see if it holds :)

Nah, never even came close :)

Yeah....I know this is true, but it is still not the whole/entire/original signal that gets sent to the compressor. It is a tapped off portion...I think.

Who knows if really this makes a huge difference??? Im not 100% sure....All I can know for sure is how it is done traditionally, by the "Pro's".......I am all for tradition, if it is logical, and I have faith that if it was better to use a compressor through the aux sends, then this is what I wouldve been taught, and this is how the professionals would do it too....

I really would like to find a better technical explanation though, even though I may not understand it fully...

Why should it be tapped off? An aux send is just a copy of the original signal which level is controlled by potentiometer. If one's mixer would have a some sort of constant filter on the AUX send, I'd ditch that mixer into a river. The whole idea of an AUX send is that it replicates the signal. There would be no point if it would get filtered or something. I've seen few mixer schematics and there are no bloody filters on AUX sends.

There are no difference in the result if you compress by a pre-fader AUX or by an insert channel. Of course some people might hear a difference (the same kind of difference that you hear when you change the case of your hifi stereo from black to red).

Some things that still bother me though,

Why dont studio's just use the aux sends for any dynamic processing then? Why do we even have insert points at all?? Why is it, in every pro studio in the world, that when using a compressor they use the insert points, and not the aux sends?

I dont buy into the argument that using a pre-fade aux send is identical to using an insert point.

For a start, you are sending the signal through an added set of circuitry, which will cause degradation to the signal. When using the pre-fader aux send, the signal goes through the EQ circuitry as well, before going out to the compressor/FX device. Using the insert points for dynamics processing is a much purer path for the audio signal.

I will find out for sure on monday, from someone who has been workin as a professional engineer for the majority of his life, who has a background in electronics, and whom I think we can trust to deliver us a verdict on this.

Very interesting stuff.......I have just been flicking through the signal flow diagrams for my Mackie 1402VLZ Pro, and my Studer 169, as well as schematics showing just how much "extra" shit you will be sending your signal through if you do use the aux sends.

I may also do some 'real' tests, not just writing down stuff I 'think' is correct....Yay, I get to play with my DBX compressor!

:)

This is obvious! When you have a compressor in insert, then you can add send AUX FX on the compressed signal without wasting additional tracks.

It's not identical. With sends you'll have to sacrifice additional track(s) for the compressed signal. With insert compressing the additional track is not needed at all. But the sound is exactly the same because AUX's and inserts are only routings. They don't do anything with the sound.

The circuit structure of an AUX send is so simple that you could stack even ten of those things in a chain wihtout hearing any additional noise or distortion (this applies even for the cheap mixers). There's only few silly resistors and an opamps.

This depends on the structure of the EQ. Usually when on "clean" setting the frequency response of the input is almost totally unaffected, which means you'll "hear" the difference with a bode plotter. And even if the EQ affects the signal it also does affect the insert compressed signal and thus the difference is really trivial.

Yup. You'll do that. I'll bet that there indeed is a difference, but the difference is inaudible.

The stuff you refer to is actually very basic components. As I said the structure of AUX-busses is very simple and on modern mixers the signal won't get audibly distorted or anything.

This has turned into one of the more interesting threads for sure.

I really am looking forward to what some Techs say about this. Please let us know when you find out Jase.

Anyway, with my little setup I still have to use the Aux sends pre-fader for some things, but knowing in more detail about it will be nice.

You know....."silly things" like resistors make all the difference.

You look at a really high end, beautiful sounding console, and the "Silly" resistors they use cost about 10 or 20 times more than the ones you would find in a Behringer/Mackie mixer. And as far as op-amps goes (chips), these things are the most horrible sounding shit you could ever hope to run a signal through. You think about all the analogue "warmth" Vs. Digital "coldness" arguments and most of the time the analogue gear they are talking about DONT use chips/op-amps, they are running through transformers and high quality capacitors/resistors etc....or tubes!

You can pay $100 for a behringer parametric EQ, full of op-amps.....and then, you could pay $10,000 for a Manley MASSIVE PASSIVE, full of beautiful circuitry made up of transformers and other high quality parts (NOT op-amps/chips) and these things are like the best sounding bit of gear you will ever come across.....you dont even need to actually use the EQ, just run your signal through it and it comes out the other end sounding "Better".......

The parts inside your mixer 100% determines the sound quality that comes out the other end. This is why shit desks sound shit, and Neve desks sound fuckin awesome!

Also, think about in Live sound, where the engineers will often use the VCA groups for sending the drum channels, because they dont want to pass their signals through another set of fader circuitry, as it will degrade the signal more so than a VCA circuitry would.....This is a normal procedure in Live sound, and one which translates into the studio world as well. Engineers will often try to record using the purest signal path, the one that doesnt pass through a whole bunch of extra circuitry, the simplest route. On it's own it may not make a lot of difference, but collectively.....?????

Gosh I wish I had more knowledge of electronics......