Expander / Compression Signal Chain Advice

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riot100

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Hi,

I'm looking for some advice regarding where in the 'signal chain', an expander and compressor should be inserted.

I have the following equipment:
Analogue 16:8:2 Mixing desk connected to an 8 Track Fostex Digital Recorder.
JoeMeek VC6Q (Pre Amp/Comp/EQ)
JoeMeek VC3Q (Pre Amp/Comp/EQ)
Symetrix 522 (Comp/Expander/Gate)

I would like to record an Acoustic Guitar and Vocal, but not necessarily at the same time.

My signal chain was going to be Acoustic Guitar/Vocal connected to VC6Q or/and VC3Q (Using Pre-Amp and Comp) via mics,
then into the Analogue Desk.
The Expander (Symetrix 522) then connected as an Insert on the Desk.

I have no No inserts on the Groups.

Having read a bit on the 'Net, am I correct in stating that the Expander should be placed in front of the Compressor.

If so, what would be my best Signal Chain usage of these units.

Thanking You.
 
Hi,

Basically I'm asking for advice on whether, when using two seperate hardware units, i.e. a Compressor and an Expander (as a downward expander), what are the best ways for application, during tracking? Compressor before or after the Expander? I've read both with google search.

What are the advantages / disadvantages? Rights / wrongs?

Would it be preferable to track straight into the Digital Recorder, and bypass the Analogue Desk?
Then use the Analogue Desk for mixing.

Thanking You.
 
Not sure why you want to use the compresser and expander if you arent clear in your own mind what their purpose is.

Normally we dont need to use either at the tracking stage. We just record the guitar, voice or whatever, as is. Good modern converters are usually well up to the task. What sort of converter/soundcard are you using?

Others will chime in shortly I'm sure.

Cheers Tim
 
Thanks for your reply Tim.

From Karl Coryat’s "Guerrilla Home Recording"

In the book he mentions recording Lead Vocals:
"...if any instrument can benefit from pre-recording compression, its vocals. Vocals are so dynamic and important, rarely does a totally uncompressed vocal work well in a recording. And it really helps to clean up the track if there's an expander in line as well..."


"...Unlike an expander, which increases dynamic range, a compressor reduces dynamic range. In recording, running a signal through both a compressor and an expander can be very effective.

Why would you want to reduce and enlarge the dynamic range at the same time? Actually, you wouldn’t.

They don’t both come into play at the same time; an expander does its thing when signals are at their quietest (or nonexistent), and a compressor does its thing in the louder part of the dynamic range..."

Thanks
 
Tracking is not the final product. It's just the act of getting the voice, guitar etc recorded onto the hard disk or whatever. From there, all sorts of production effects including compression, reverb, EQ etc can be used on that recording in the process of polishing the final product.

Unlike the days of old we now have the luxury of recording a voice or guitar with no effects at all, and then coming back to it later and using those effects to sweeten it. We can change our setting a hundred times if we like and still we have the original vocal track to go back to.

In the earlier days of analog tape and direct disc cutting before that, the dynamics of a lively singing voice could easily outstrip the limitations of the recorder and so yes compression and EQ was used, but more so as to make it easier on the recording medium.

These days we still use compression but mostly to even out extremes in dynamics after they have already been recorded to make the performance more listenable and pleasant and to make the various voices and instruments blend harmoniously together.

What the writer says is sort of correct but why would you need to use an expander unless there was background noise? If there is significant unwanted noise the best thing to do is try and get rid of it! An expander or noise gate in such a scenario is at best a compromise. We try to record in a quiet place.
 
Guerrilla Home Recording is written for the home recordist who cannot get rid of the excessive background noise. It's written as a method for getting the best possible sound in environments that are far less than ideal. While improving the environment is definitely possible in most situations (and the book does go into some of that), there's only so much that can be done on the very very cheap.
That being said, Tim's right. If you are recording in a modern digital medium, then you are recording at 24 bits. This gives you plenty of headroom to work with. Just get your vocal recording sounding the best you can completely clean, make sure that you're not ever digitally clipping, and then use your effects. If you really want to use those external bits of hardware, send your recorded track from your DAW to the external unit, then re-record the output. A big advantage of this is that, instead of somebody telling you how to do it (which isn't really gonna help cause we can't hear what you are trying to fix with the effects), you can play with the settings on your hardware, as well as the order in which it is connected, until it sounds best to your ears.
 
+1 to what everyone has said but...

While you really don't need to compress/expand on the way in to the computer in a 24bit system if you have a nice compressor that adds a flavour/coloration to the sound that you like and want in your recordings, that you cannot adequately reproduce in software then that's a good reason to do it.
Also if you are/have a vocalist who is going from a whisper to a scream throughout the recordings and you don't have the kind of set up where you can be proactively raising and lowering the pre amp gain to anticipate then compression/expander is a great way to ensure you keep the signal level where you want it and not be worrying about clipping the preamps and converters which will definitely have a bad effect on your sound.

Finally there is something to be said to comitting to a sound at tracking time and not going back and tweaking the compression settings 200 times after tracking is done. Sort of forces you to 1) get the best recording you can get when you track because you don't have the option to 2) waste hours with after the fact tweaking
 
riot100 said:
Why would you want to reduce and enlarge the dynamic range at the same time? Actually, you wouldn’t.
Click to expand...

I agree with that,

riot100 said:
They don’t both come into play at the same time; an expander does its thing when signals are at their quietest (or nonexistent), and a compressor does its thing in the louder part of the dynamic range..."
Click to expand...

That's not really true.. Compressors make loud things quieter and quiet things louder. They operate on quiet AND loud sounds, bringing them towards a common volume. Expanders are the opposite, they make quiet things quieter and loud things louder, they push volumes AWAY from some volume threshold.

Which is why I agree with the statement above. Cuz why would you bother making your loud parts quieter, then run them thru an expander just to make em louder again? You'd be adding extra connectinos, noise, fail points, etc to your signal chain for no reason.
 
suprstar said:
Compressors make loud things quieter and quiet things louder.
Click to expand...

Not quite; they only act on anything over the threshold ("make the loud things quieter"), but in doing so the quieter things will become comparatively louder in relation. That was worded really badly, but you get the idea :p


Whilst it seems counter intuitive/productive, I can think of a few situations where you might use both signal processes that decrease and increase dynamic range in the same signal chain... its not uncommon (though I don't like doing it) to both gate and compress drum parts, and if you had a live vocal recording you might want to drop the level of some bleed between vocal lines using an expander and at the same time use a compressor to catch some peaks and smooth out the 'other end' of the signal.
 
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Yeah but (99% of the time) you add some makeup gain or bump your faders up, so (99% of the time) the quiets under that threshold get more volume.

Yeah, expander -> gate -> compressor, I could see doing that just to make the gate more effective, altho theoretically that sounds awfully similar to just raising the threshold on your gate...
 
Thank you for all your prompt replies.

I'm only recording in my bedroom - low end home recording.
Wanted to get back to a bit more analogue recording (at the front end aleast), hence the Analogue Desk.

Not using my small DAW (connected via two input only M-Audio Duo), except for cleaning up the start and end of the final stereo track file.

Using the Analogue 16:8:2 Mixing Desk and recording onto an 8 Track Hard Disk Multi recorder.
Just thought from what I have been reading about the Compressor and Expander units, that it would help the dynamics, and the expander would clean up (reduce noise) of the vocals (when not singing) and guitars.

So this is way I was asking about the Signal chain and where the seperate units fit into this.

Thnaks
 
Well, that was assuming we were talking about standard downward compression. Upward compression works in the opposite way, acting on things below the threshold - never used it myself.

suprstar said:
Yeah, expander -> gate -> compressor, I could see doing that just to make the gate more effective, altho theoretically that sounds awfully similar to just raising the threshold on your gate...
Click to expand...

I wasn't saying gate and expander, just gate or expander :) But they're essentially one and the same - you can say that a gate is simply an expander with an infinite ratio.
 
The problem is, by trying to reduce noise, you're adding so many things into your signal chain that you're sort of defeating the purpose. By the time your signal goes through an expander, a gate, and a comprssor, you've potentiallly added more noise than you're trying to get rid of.
 
Yea, I have to agree actually; I forgot we were actually about analog hardware here. I'm too used to working completely ITB and was just thinking about the processing, not the logistics of hooking everything up. Maybe I should get some real outboard to give me a kick from reality rather than relying on all the UAD stuff all the time :p
 
As far as I can understand it,
If you've got your room as quiet as you can, but you're still getting an unacceptably high noise floor, the expander would serve to lower your noise floor. This would be especially necessary in a situation where you want to use compression, which raises your noise floor.
The chain would be expander first (to lower the noise floor of silent passages) followed by compressor (to tame the dynamics of the louder parts of the vocal line). The threshold on the expander would be set, I'd assume, to just above the noise floor, while the threshold on the compressor would be set to wherever it needs to be to do the taming you want.

This would effectively cut out some of the background noise during "silent" parts, though it would obviously still be audible while you were singing. Which is maybe the point of using an expander instead of a pure gate, since if the background noise is gonna be audible when you're singing anyway, it'd sound a little unnatural for that noise to just disappear and reappear entirely.

I dunno, am I all mixed up here?
 
The Cancers said:
I dunno, am I all mixed up here?
Click to expand...

Nope, you're dead on :p

Like you say, gates can sound very unnatural, especially for things like vocals on live recordings (ohhh, the dreaded-yet-fairly-unavoidable-in-small-venues situation of lead-vocal-mic-picking-up-all-the-cymbals-from-the-horrendously-loud-kit-right-behind-it... phhewww, that was a mouthful). Expanders can be a bit more subtle but still be very effective at helping out with taming 'things'.


And I've strayed slightly off topic again - why am I talking about live (and live recording) situations? This is in the context of a studio. Argh...

I'm not in a writing mood tonight... nothing I write seems to come out quite as I think it in my head. Can't put things into sensible words properly. Need some sleep :)
 
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