Compression using spaced pair - channel insert or post fade insert?

[karambos]

If I am recording using a spaced pair micing setup and I want light
compression on both mics, would the serious studio engineer use two
seperate compressors as inserts on two seperate channels on the mixing
desk or are there compressors out there capable of dealing with two
inputs and which have two outputs?

Or would you somehow send the post fade stereo signal into one
compressor before sending it to whatever recording medium you are
using (in my case the hard drive)?

I'm confused about how to apply compression the best.

[EricK]

karambos wrote:
> If I am recording using a spaced pair micing setup and I want light
> compression on both mics, would the serious studio engineer use two
> seperate compressors as inserts on two seperate channels on the mixing
> desk or are there compressors out there capable of dealing with two
> inputs and which have two outputs?
>
> Or would you somehow send the post fade stereo signal into one
> compressor before sending it to whatever recording medium you are
> using (in my case the hard drive)?
>
> I'm confused about how to apply compression the best.

You need a 2 channel compressor that has the ability to "link" the two
channels. In this configuration, gain reduction is applied equally to
both channels, so as to maintain the stereo image.


--
Eric

Practice Your Mixing Skills
Multi-Track Masters on CD-ROM
www.Raw-Tracks.com

[Arny Krueger]

"karambos" > wrote in message
om

> If I am recording using a spaced pair micing setup and I want light
> compression on both mics, would the serious studio engineer use two
> seperate compressors as inserts on two seperate channels on the mixing
> desk or are there compressors out there capable of dealing with two
> inputs and which have two outputs?

There are definately compressors that have two independent sections that can
be easily linked.

However, two questions - what's the context, and what's the goal?

For example, are other mics being used?

What's the source? Vocal, instrumental?

What's the purpose of the recording?

When recording to hard disk, this implies the use of a DAW, and DAWs
generally have compression of their own.

> Or would you somehow send the post fade stereo signal into one
> compressor before sending it to whatever recording medium you are
> using (in my case the hard drive)?

Generally, post fade is a suboptimal place to do compression because the
faders are there to introduce level changes that the compressor is there to
make go away. That's an over-simplification, but perhaps it conveys a useful
idea. You push the faders down, and the compressor tries to bring the levels
back up until you slip below the lower (noise gate) threshold. Then, plunk!
You push the faders up and the limiter tries to bring the levels back down,
but makes things sound like mush in the process. None of this is very
pretty to listen to.

OTOH, my only use of compression is post fade, driving a cassette recorder.
I use an inexpensive Behr DSP 1424 stereo compressor to keep the levels up
on cassette tapes I make of worship services. This is all post-fade,
involving about a dozen or more mics and other sources. In this case excess
dynamic range is a bad thing because of the recording medium and the
intended use. The DSP 1424 is probably a POS, but so is cassette as a high
performance audio medium.

> I'm confused about how to apply compression the best.

What's the context, and what's the goal?

"karambos" > wrote in message
om...
> If I am recording using a spaced pair micing setup and I want light
> compression on both mics, would the serious studio engineer use two
> seperate compressors as inserts on two seperate channels on the mixing
> desk or are there compressors out there capable of dealing with two
> inputs and which have two outputs?

The serious engineer would use a stereo compressor or a dual-mono one that
allows you to link both channels. Or more rightly said: since you're
recording to digital, the serious engineer might not even use a compressor
at all going in, unless he was looking for a specific manner in which to
affect the tonality of the sound... IOW, if it's just "light" compression
you're going for, you could probably save it until mixdown.

> Or would you somehow send the post fade stereo signal into one
> compressor before sending it to whatever recording medium you are
> using (in my case the hard drive)?

Do you mean in addition to a direct signal without compression? If so, it
couldn't hurt anything.
--


Neil Henderson
Saqqara Records
http://www.saqqararecords.com

[Mike Rivers]

In article > writes:

> If I am recording using a spaced pair micing setup and I want light
> compression on both mics, would the serious studio engineer use two
> seperate compressors as inserts on two seperate channels on the mixing
> desk or are there compressors out there capable of dealing with two
> inputs and which have two outputs?

The latter. A "stereo" compressor applies the same amount of gain
reduction to both channels so the image won't wander.

> Or would you somehow send the post fade stereo signal into one
> compressor before sending it to whatever recording medium you are
> using (in my case the hard drive)?

No. It makes little sense to apply compression post-fader, unless you
never plan to move the fader.

> I'm confused about how to apply compression the best.

It might be best, particularly since you seem to have little
experience with this, to set the recording level very conservatively
and record with no compression. Then decide later if you really need
to compress. You can then experiment without changing the original
recording.

Suppress any compulsion to keep the levels hot so as to avoid
compromising resolution or signal-to-noise ratio unless you're using a
recorder that works at less than 16 bits. Not many of them around
these days.




--
I'm really Mike Rivers )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo

[Scott Dorsey]

karambos > wrote:
>If I am recording using a spaced pair micing setup and I want light
>compression on both mics, would the serious studio engineer use two
>seperate compressors as inserts on two seperate channels on the mixing
>desk or are there compressors out there capable of dealing with two
>inputs and which have two outputs?

If you compress a stereo pair, you need either a stereo compressor (and
the RNC is a good example of this), or a pair of compressors with "link"
connectors so that the control paths can be tied together.

If you don't have the two channels linked, the stereo image will shirt
around a lot as the compressors operate.

>Or would you somehow send the post fade stereo signal into one
>compressor before sending it to whatever recording medium you are
>using (in my case the hard drive)?
>
>I'm confused about how to apply compression the best.

Personally, I wouldn'd compress at all in most cases, but that's just me.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[Laurence Payne]

On 9 Aug 2004 03:47:57 -0700, (karambos) wrote:

>If I am recording using a spaced pair micing setup and I want light
>compression on both mics, would the serious studio engineer use two
>seperate compressors as inserts on two seperate channels on the mixing
>desk or are there compressors out there capable of dealing with two
>inputs and which have two outputs?

Some compressors can be linked so that a stereo image is retained.
Often two such are mounted in one box and called a "Stereo
Compressor".
>
>Or would you somehow send the post fade stereo signal into one
>compressor before sending it to whatever recording medium you are
>using (in my case the hard drive)?

If you're recording to digital, why do you want input compression at
all? Particularly if true stereo is your goal.

CubaseFAQ www.laurencepayne.co.uk/CubaseFAQ.htm
"Possibly the world's least impressive web site": George Perfect

[David Morgan \(MAMS\)]

"karambos" > wrote in message

> If I am recording using a spaced pair micing setup and I want light
> compression on both mics, would the serious studio engineer use two
> seperate compressors as inserts on two seperate channels on the mixing
> desk or are there compressors out there capable of dealing with two
> inputs and which have two outputs?

If you're mixing those two inputs with others, I'd say a stereo (or linked
mono if necessary) compressor on the applicable channel inserts of
your mixer.

> Or would you somehow send the post fade stereo signal into one
> compressor before sending it to whatever recording medium you are
> using (in my case the hard drive)?

If these were my only two mics for the mix and I felt they really needed
compression, I'd place the compressor directly in the path between the
mic preamp or mixer outputs and the recording device.

> I'm confused about how to apply compression the best.

Don't be.... there's a number of different ways to approach compression
and seemingly infinite parameters to it's adjustability and usefullness of
purpose.

--
David Morgan (MAMS)
http://www.m-a-m-s DOT com
Morgan Audio Media Service
Dallas, Texas (214) 662-9901
_______________________________________
http://www.artisan-recordingstudio.com

[Arny Krueger]

"ScotFraser" > wrote in message

> << Am I the only looney tune that often runs 2-mixes through unlinked
> compression? >>
>
> No. Linking the detecters is not really necessary if you don't have a
> lot of signal exclusive to only one side of the stereo, & if you're
> not hitting the compressors very hard. I've never heard my Red 7's
> pulling the image one way or the other when using them on an ORTF
> signal, with rather minimal gain reduction.

Not to pick at words, but wouldn't unlinked compressors be unlikely to pull
the image to the L or R. but rather tend to narrow it?

[ScotFraser]

<< Not to pick at words, but wouldn't unlinked compressors be unlikely to pull
the image to the L or R. but rather tend to narrow it? >>

I think narrowing would be the less extreme result & image shifting to the
opposite side the more extreme result. I've never intentionally mis-set
unlinked compressors to the point that would demonstrate the effect, though.


Scott Fraser

[Peter Larsen]

karambos wrote:

> If I am recording using a spaced pair micing setup and I
> want light compression on both mics,

This depends on the context, but the general answer is "no, you don't"
in case of a purist style recording.

> would the serious studio engineer use two
> seperate compressors as inserts on two seperate
> channels on the mixing desk or are there compressors
> out there capable of dealing with two
> inputs and which have two outputs?

Stereo is best compressed with a stereo compressor if relevant. However
even if the stereo pair in question is a room or audience pair, then you
still do not want to have compression on them in recording because the
compression will cause imaging and perspective changes. There is
probably some exception to this ...

> I'm confused about how to apply compression the best.

There is no such thing as "best way" to apply compression, it is about
the context and about what problem you want to solve by applying it. You
do not want to apply it unless there is a problem it solves. Any
treatment of the sound causes deterioration and loss of clarity, it is a
trade-off and you do not want to give quality away without getting some
solution of some problem in exchange. The fewer stages the better and
the less processing the better. Digital or analog .. no difference,
processing causes loss of clarity and openness.


Kind regards

Peter Larsen

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* My site is at: http://www.muyiovatki.dk *
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[Peter Larsen]

Arny Krueger wrote:

> Not to pick at words, but wouldn't unlinked compressors be
> unlikely to pull the image to the L or R. but rather tend
> to narrow it?

No way they could. The issue is that a loud something in one channel can
lead to a ducking of the other channel that is more audible than the
brief image shift.


Kind regards

Peter Larsen


--
*******************************************
* My site is at: http://www.muyiovatki.dk *
*******************************************