What's the diff in pre-/post- fader sends?

[PaulG]

Could someone be so kind as to explain what the differences are in pre- and post- fader sending to a bus and why you'd choose one over the other?

Thanks a whole lot,

- Paul

[shamann]

Pre-fader means you can send a signal out without the original channel being audible in the master mix, whereas post, both the channel and the send are audible. At least on my little mixer I use for live work.

[bk]

Pre fader is a signal taken from before the fader, meaning the fader will have no effect on the signal being sent to the prefade output. These are good for setting up a monitor mix, where you don't really want the main fader to effect your monitor mix.

Post fade is a signal taken after the fader, and thus will be affected by the main fader. These are good for FX sends (ie reverb) where you want the balance of effect-to-signal to remain the same, regardless of the fader setting. If you use a prefade send to a reverb, and you lower the fader, the amount of reverb will remain the same, while the dry signal decreases, thus burying the signal deeper into the reverb.

There's no rule, really, for how they are used. Just depends on what you are trying to achieve.

[annode]

To add more to the other replies;

- You can also think of it as a way to "split" a signal off into more then one mixer channel.
- [in cubase] in a mixer channel's insert section, the last two slots at the bottom of the column are always pre-fader, [bypassing the channel volume control] inserts. It is, in this way, you may insert dynamics such as compression and limiting.
Because compression or limiting is placed pre-fader,the signal coming into either of them will always be "input directly" at a constant level...the channel fader volume will control only the "output" volume of the last two slots and not the input volume of whatever is in the last two effect/insert slots. [this may be true to other software sequencers. Read your docs 'pre-fader' section.]

Compression and limiting as an example,need,and work best, in this configuration.
Think of it this way. in a cubase track's mixer channel, the volume fader-control varies the track's audio being fed to each input of each insert-effect in all insert slots except the bottom two.
These insert-effect outputs,[post-fader] are routed to the "inputs" of whatever is placed in the last two insert-slots. The output of the bottom insert-slot gets routed to the master output stage.
So, if a mixer channel has 6 insert-slots, the fader controls the input "gain" ,[pre-fader] of the track's signal fed to slots 1 through 4 consecutively.
The output of insert-slot 4 ,[the series mix of all insert-effects 1-4] is "fed" to the input of insert-slots 5 through 6 consecutively.
This then is routed to the master output channel.

Understanding this can open new routing configurations for you.

[amarule]

Prefader: Before the mix fader, often also before the eq and insert point(sometimes selectable pre or post eq). Most desireable for monitor sends for stage or recording. Unaffected by changes in main mix levels.

Postfader: after the mix fader, eq and insert point. More commonly used for effects sends to reverbs, delays, etc.

[annode]

Prefader: Before the mix fader, often also before the eq and insert point(sometimes selectable pre or post eq). Most desireable for monitor sends for stage or recording. Unaffected by changes in main mix levels.

Postfader: after the mix fader, eq and insert point. More commonly used for effects sends to reverbs, delays, etc.

Thank you amarule.
I'm glad you covered what was not covered up to this point.

[Chester Desmond]

I'm not trying to debate you here, but trying to clarify my understanding since I am using Cubase SE1 (which I'm not sure qualifies to your statements anyways)

Think of it this way. in a cubase track's mixer channel, the volume fader-control varies the track's audio being fed to each input of each insert-effect in all insert slots except the bottom two.

I thought inserts were in series, and the signal would pass through the chain of effects, but you are saying each insert is taking the input from the track and effecting it? In a typical insert loop the signal is tapped at the insert point, sent to the effect and then back into the channel; you almost seem to be saying here that each insert is getting the clean (original) signal which leaves me wondering where the ouput is summed and how (ie 4 parallel steams summed into insert slot 5, or the signal after passing through the chain of inserts 1-4 is fed to ins. slot 5)

These insert-effect outputs,[post-fader] are routed to the "inputs" of whatever is placed in the last two insert-slots. The output of the bottom insert-slot gets routed to the master output stage.

"Post-fader" to me means that whatever changes you have made in volume will be passed along at the post fader stage; since the fader is being used to control input gain how can it also be used to control the channel's volume in the mix (ie volume sent to master output)?

So, if a mixer channel has 6 insert-slots, the fader controls the input "gain" ,[pre-fader] of the track's signal fed to slots 1 through 4 consecutively.
The output of insert-slot 4 ,[the series mix of all insert-effects 1-4] is "fed" to the input of insert-slots 5 through 6 consecutively.
This then is routed to the master output channel.

Here you are saying "...the series mix of all insert fx..." which makes more sense to me than the wording in the first paragraph; still I don't understand where the setting of the track's volume in the mix is occurring (again, since the fader is being used for input gain). Do you use the output\makeup gain of the final effect in slot 6? If you have nothing in slots 5 and 6, does the (series mix of 1-4) signal go straight from #4 to the master?

I am probably just missing a piece of the puzzle.

Thanks!

[annode]

Hi Chester Desmond. You have made some very astute observations.

I wrote responses to each of your questions. It wasn't until I got to the last one where I began to realize the world wasn't flat. I thought it was!

I did make writing errors in each of those points you mentioned...but I had the whole concept backwards I see now.
Setting up a test in nuendo I see that the fader in each channel and master is inserted between slot 6 and 7. This means that 1-6 are pre-fader and 7-8 are post fader.

In my mind it was the oposite.I don't think i'm dyslexic. screwy yes.

You have rocked my world Chester. lol I'm so gald you did though. I need time to absorb this.

[annode]

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[amarule]

Annode, great visuals, however I believe in Cubase you can also make the pre fader points pre eq as well, so your drawing is not absolute.

[annode]

Annode, great visuals, however I believe in Cubase you can also make the pre fader points pre eq as well, so your drawing is not absolute.

Looking at the the diagram that would have to be the pre-fader sends your talking about. Could you be more clear? Oh,it's not MY drawing, it's from the sx3 docs.

I searched the docs for anyway to move the EQ position and didn't see anything in nuendo or sx.
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Can anyone tell me how to use this...a "routing editor?" there doesn't seem to be anything on it in the docs. The window help button dropdown opens nothing.
I setup some meters to watch signal flow. I puched the routing editer's buttons. Nothing seemed to happen.