I need to read as much as I can and educate my self about using compressors
and limiters.
I use Protools and would be using their plug-in.
I have just voices that I need "sweeten". The sound is on a video tape which
the Avid Xpress people are going to export as a QuickTime file. But it's raw
and needs some tampering with.
Are there any online articles about compressor/limiters that I could read?
If so do any of them talk about the plug-ins in PT, or the Waves plug-ins?

Thanks

IS

"IS" wrote in message
m...
I need to read as much as I can and educate my self about using
compressors
and limiters.
I use Protools and would be using their plug-in.
I have just voices that I need "sweeten". The sound is on a video tape
which
the Avid Xpress people are going to export as a QuickTime file. But it's
raw
and needs some tampering with.
Are there any online articles about compressor/limiters that I could read?
If so do any of them talk about the plug-ins in PT, or the Waves plug-ins?




Mar 18, 7:38 pm show options

From: - Find messages by this author
Date: Fri, 18 Mar 2005 19:38:54 -0800
Local: Fri, Mar 18 2005 7:38 pm
Subject: Compression & Limiting Revised
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Compression and Limiting


The main job of a comp/limit is to reduce the dynamic range of a
signal. The comp/limit reduces the loud part of the signal it does not
bring up the lower parts. That function is done by the prod/eng. Under
what circumstances is this a good idea, and what, if any, are the
trade-offs? One of the side effects of compression is that the sound
being processed changes: the more you comp/limit the more you alter the
fidelity of the signal. Comp/limit is used for two purposes as in all
processing 1) to manage the signal and remove any sonic dynamic
problems, and 2) to be creative. In managing the signal, the comp/limit
should sound transparent the signal sounds dynamically unaffected..
That means it is doing its job without any noticeable degradation to
the signal. In creative situations you will utilize the comp/limit to
alter signals to achieve desired effects.


Most vocalists (and some musicians) need comp/limit to keep their
levels even; bringing down the peaks means that you can make the
average signal level higher (Manually bringing up the output) and more
audible in the mix and this results in a tighter, more confident sound
that sits well in a mix. However, don't just rush in and apply maximum
comp/limit. Listen to the singer run through the song, watch the record
level meters, and try to decide for yourself whether the voice needs a
lot of control or simply a light touch. In any event, it's better to
limit during recording, to prevent digital distortion from occurring in
storing the signal to hard drive. Analog tape takes a lot of level and
the inherent distortion is more palatable to the ear. Remember that
digital distortion is very unpleasant. Some of the better A-D
converters incorporate hard limiting to prevent distortions. Other
cheaper converters will just simply shut you down and not process at
all. 16 & 24-bit digital storage is very quiet when used properly,
allowing you to always apply more comp/limit when you come to the mix
stage, whereas over-comp/limit is impossible to reverse when recorded
that way. With today's DAW's (24 bit) there is virtually no need to
dynamically process a signal for level control that can be done in a
mixing stage without introducing noise problems. It is best to use
comp/limit in the monitor stage when recording and then accurately
processing the dynamics in the final mixing stage.


Limiting


Limiting is designated as a high compression ratio, any ratio from 8:1
- infinity. I however believe that limiting is just as much based on
the attack and release times as is the high ratio. For example, If you
are limiting a vocal that has a lot of transients and you use a ratio
of 8:1 or higher with an attack time of more than 50ms, what really
happens is that all the transients go through unaffected and the
resonance or rms value of the signal gets limited. What has been done
here is the exact opposite, instead of dynamically reducing the range,
you have actually expanded it for the transients are passing through
unaffected. Limiting incorporates very fast attack and release times.
Attack time 1ms-10ms, release time 20ms-40ms (approx). I believe
limiting should be used to manage fast acting transients in a signal.
Broadcast transmission always incorporates limiting to prevent their
transmitters from blowing up. However, they commonly use very slow
release times to avoid any pumping and breathing effects. Any audio
signal that contains random transient's work well when limited rather
than compressed such as drums, lead vocals and guitars.


Compression


Compression uses ratios from 1.5:1 - 7:1. The goal is to tighten up
the dynamic range of a signal so it can be heard easily throughout a
mix such as a lead vocal. Compression usually incorporates medium to
slow attack and release times. Attack 25-100ms Release 200ms-400ms. If
you want a more percussive sound use even longer attack times, this
will allow the transients to go pass through and the resonance or rms
part of the signal gets dynamically reduced. In Genesis song "Mama"
the vocal is very compressed with a slow attack time giving the vocal a
very aggressive percussive sound.
If a vocal (or instrument)) needs to be limited and compressed so it
can sound transparent, first try inserting the vocal into an input that
you can ride the level and then buss assign to another input. First,
insert a de-esser if there is sibilance problems. It is critical that
the de-esser comes first in the chain. Second insert a limiter and
reduce some of the random transients that might occur when a singer is
singing very loud. Third EQ what you need to enhance the signal,
remember to clean up the low end so it doesn't influence the effect
of compression. Fourth, Compress as required. Remember it is a process
that requires fine tuning in all stages.


Input


The input level of the signal to the comp/limit should be set to around
0VU with occasional excursions going up to +3VU if then ratio is set to
3:1. Too much gain in the input stage will introduce distortion. Not
enough gain will cause increases in the amplification stage of the
comp/limit increasing additional unnecessary noise to the signal. When
setting up a comp/limit, use an oscillator from the board set at 0VU
and set the input and output of the compressor to 0VU. This is known as
Unity Gain.


Setting the Ratio


If you have a ratio of 4:1 that indicates that for every 4db over the
threshold only 1db will be added to the output of the signal below the
threshold. For example: if you have a signal that is peaking at 88db
and the threshold is set at 80db the final output will now be 82db.


Threshold


It determines the upper area of the dynamic range that needs to be
comp/limit. The lower the threshold the more of the signal will be
comp/limit. The Threshold is preset manually by the prod/eng. Make sure
that the comp/limit continually returns to 0db of gain reduction. If
you notice that the gain reduction meter is continually going back and
forth between
-8VU and -4VU at a 4:1 ratio, that means the signal is being comp/limit
too much thus degrading the quality of the signal. Reset the threshold
so that the meter reads between -4VU and 0VU to minimize any
degradation to the signal. Remember that the more you comp/limit a
signal, the more the quality of the signal is affected, especially
dealing with harmonic content. If you need to really comp/limit a
signal try to use a tube comp/limit, which will produce distortion that
is more palatable to the ear.


Attack Time


This is the time it takes for the comp/limit to start processing once
the threshold has been crossed on the increasing amplitude side of the
wavelength of the signal. Attack times vary from less than 1ms to
almost a second. Some comp/limit have Auto-Attack (VCA).


Release Time


This is the time it takes for the signal to return to its original
level after the signal has crossed the threshold of the downward part
of the envelope. The release time's length is determined by the
prod/eng. Some comp/limits have an Auto-Release function (VCA) which
does the job for you and works well for lead vocalists. To prevent low
frequency distortion (half cycle-length) a med-long release time is
required. Short release times are often desired but may produce pumping
and breathing effects.


Hard Knee/Soft Knee Compression


If the comp/limit ratio is set to 6:1 with a soft knee, once the
threshold has been crossed the comp/limit, over time (ms) will go from
1:1 and rise to 6:1 compression. This results in a smooth transition
from the on-set of compression to full pre-set compression. With a hard
knee this transition is immediate. Soft-knee compression usually
provides the smoothest compression, but hard-knee models give tighter
control and may be better for creating hard compression effects.


Noise


Comp/limit are not inherently noisy devices, but because they reduce
the dynamic range of the signal being treated, some make-up gain is
needed to bring the signal level back to Unity Gain. Although
comp/limit really just turn down loud sounds, once you've adjusted the
make-up gain control, the loud sounds are back where they were and the
quieter sounds are much louder. If you're compressing to achieve 10dB
of gain reduction, any noise that happens to be part of the signal will
also be increased by 10dB for all input levels that are below the
threshold. Periods of silence between words or phrases are most
vulnerable, as it's here that the comp/limit gain is highest. As well
as starting off with the cleanest signal you can, it might be wise to
gate the signal immediately before it enters the comp/limit. Some
comp/limit have built-in expander gates for this purpose: used
properly, they really can make a difference. If there is a lot of
output noise like that is found in some tube comp/limit, you might need
to insert an expander to minimize the noise.


Multi-Band Compression


When a certain frequency range becomes a problem, the user can help to
target the problem area and compress the undesirable frequencies. If an
acoustic guitar has too much low frequency build up you can compress
only the low frequencies and leave the upper frequencies alone where
the guitar remains harmonically intact. This also works well when you
need to remove sibilance from vocals.


Getting a Loud Sounding Mix


This process is still very misunderstood with today's productions.
I've discovered that in the rock genre there were a lot of
productions that sound awful. When it came to finalizing or mastering
their mix they all seemed to have employed a lot of hard wall limiting
and a lot of equalization in the mid-range and high frequency range.


If you desire this effect and your mix already sounds balanced in level
throughout, first limit with a super fast attack (less than 1ms) and
fast release time (10 - 20ms). With most mixes today the number of
transients and their duration contribute little to the overall length
of the song. If you noticed that there are 50 (approx) transients in
your production, the transient duration will be 2ms (approx) in
duration. If you wanted to get this production sounding 4x louder you
would need to limit the top 6db of the production. For example: if the
maximum head room is 90db and these 50 transients are reaching this
level you can limit all these transients down to a level of 84db and
then bring up the entire production back to 90db, thus increasing the
overall level by 6db. The amount of signal that has been affected is
only 1/10th of a second. What you have effectively done is limited
1/10th of one second of a production that is 5 minutes in length. In
other words you have only limited 1/3000th of the time of the 5-minute
production. Be aware of half-cycle distortion due to short release
times. The best way to target the optimum release time is to solo the
bass and bass drum in the mix and listen for any distortion or a grainy
sounding effect. If this occurs lengthen the release time until it
disappears. It is easier to solve this problem by soloing the low
frequency content of the mix rather than listening to the entire mix.


Next, add in the EQ needed. This will prevent the limiter from working
harder than necessary. The transients have now been flattened out
slightly so if any high end is required it will not be that much
because the duration of limited transients are now longer and more
noticeable to the ear. If you put on more high end before you limit you
would need to add more to hear the effect on the transient percussive
parts of the production, whereby making the limiter work harder.


After EQ you can now compress to create an overall loudness effect to
the mix. Use ratios of 3:1 - 6:1 with medium attack (40-80ms) and
release times (100-250ms).


If your mix has major level discrepancies between the verses and
choruses, try this set-up compress-EQ-Limit


Getting A Punchy Mix


When you have finished the mix and feel it is soft and not rhythmically
defined as you like you can create a little punch and make it kick a
bit more. First limit just a little to get the odd transient out. That
should not be hard, for you have already declared that the mix needs to
sound more transient throughout. Once you have done this, clean up the
extraneous low bottom end and focus on getting low end to speak around
100hz. Add in a little mid-range from 2-4khz and the compress with the
following settings. A ratio of 4-6:1, with an attack time from 50-100ms
and a release time of 150-300ms.


Getting a Radio/TV friendly mix


The way broadcast works is that they insert settings of infinity : 1 as
the limiting ratio, super fast attack times (micro-sec) and very long
release times (3-6 sec). This means that if you have a high transient
in your mix, the station's limiter will grab it and keep your mix
down in level for at least a couple of seconds, even though the
transient lasted for only a very short time. To get around this,
incorporate your own limiting that resembles the broadcasters, except
shorten the release time to as fast as possible. This will allow your
mix to get back to its normal level almost immediately. The goal here
is to get in and out as fast as possible. Be aware of half-cycle
distortion!


Linking 2 Comp/limit


If a situation calls for comp/limit on a stereo source like a grand
piano, overheads, room mics... you will need to link your 2 mono
comp/limit's together so that their attack and release functions work
in sync. This prevents random imaging problems. If a piano player hits
a low note with their left hand at a very loud volume, the stereo
comp/limit will bring down the output of the other comp/limit (right
hand) the same amount and at the same time, keeping the stereo image
intact. When setting up make sure that one of the comp/limit is set as
the master by using the link button.


PDF available @



Reply


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In article writes:

I need to read as much as I can and educate my self about using compressors
and limiters.

Using them is better than reading about them. Get one and plug it in.

Are there any online articles about compressor/limiters that I could read?

http://www.manleylabs.com/techpage/c...s_exposed.html



--
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 he double-m-eleven-double-zero at yahoo

And remember, limiting and distorton are almost the same thing.

You should get this: The Waves Renaissance Compressor plugin.

It does a nice job, and is real easy to use.

Basically what you want is the vocals to not be super loud, then super
quiet. The compressor will smooth that out for you.

So what you do is put the compressor on the "insert" of the vocal
track. Then lower the "threshold" on the compressor controls about a
centimeter. Then watch the gain reduction meter. It should light up a
little very often. And whenever there is a big blast of vocal sound,
it should light up a lot. The more it lights up, the more it is
clamping down on the volume to make sure it doesn't get too loud.

If your basic signal is very quiet, you will want to boost the input
control on the compressor. Keep messing with the input level and the
ratio control until you see the lights go on and off like described
above.

There are other controls like "release" and "vintage" and "ARC". Just
set them to vintage or ARC and then leave them alone and concentrate on
the input level and ratio controls. That's a good way to go for you
since you are new at this.

There are many compressors and limiters, but the Waves Renaissance
Compressor is affordable, easy to use, and it's hard to get a bad sound
out of.

Contrast that with the Waves L1 limiter. It's aggressive and will
clamp the sound down, but it starts making the sound of the track hard
and annoying very soon, and very often.

The Renaissance Compressor will give you the smoothness you need
without the harsh sound added to it.

You should get this: The Waves Renaissance Compressor plugin.

It does a nice job, and is real easy to use.

Basically what you want is the vocals to not be super loud, then super
quiet. The compressor will smooth that out for you.

So what you do is put the compressor on the "insert" of the vocal
track. Then lower the "threshold" on the compressor controls about a
centimeter. Then watch the gain reduction meter. It should light up a
little very often. And whenever there is a big blast of vocal sound,
it should light up a lot. The more it lights up, the more it is
clamping down on the volume to make sure it doesn't get too loud.

If your basic signal is very quiet, you will want to boost the input
control on the compressor. Keep messing with the input level and the
ratio control until you see the lights go on and off like described
above.

There are other controls like "release" and "vintage" and "ARC". Just
set them to vintage or ARC and then leave them alone and concentrate on
the input level and ratio controls. That's a good way to go for you
since you are new at this.

There are many compressors and limiters, but the Waves Renaissance
Compressor is affordable, easy to use, and it's hard to get a bad sound
out of.

Contrast that with the Waves L1 limiter. It's aggressive and will
clamp the sound down, but it starts making the sound of the track hard
and annoying very soon, and very often.

The Renaissance Compressor will give you the smoothness you need
without the harsh sound added to it.

I have the Waves Renaissance plug-in. Got it mostly because I like the sound
of the reverb. Never worked with the Compressor before.
I will try what you suggested and take it from there.
Thanks.

IS


wrote in message
oups.com...
You should get this: The Waves Renaissance Compressor plugin.

It does a nice job, and is real easy to use.

Basically what you want is the vocals to not be super loud, then super
quiet. The compressor will smooth that out for you.

So what you do is put the compressor on the "insert" of the vocal
track. Then lower the "threshold" on the compressor controls about a
centimeter. Then watch the gain reduction meter. It should light up a
little very often. And whenever there is a big blast of vocal sound,
it should light up a lot. The more it lights up, the more it is
clamping down on the volume to make sure it doesn't get too loud.

If your basic signal is very quiet, you will want to boost the input
control on the compressor. Keep messing with the input level and the
ratio control until you see the lights go on and off like described
above.

There are other controls like "release" and "vintage" and "ARC". Just
set them to vintage or ARC and then leave them alone and concentrate on
the input level and ratio controls. That's a good way to go for you
since you are new at this.

There are many compressors and limiters, but the Waves Renaissance
Compressor is affordable, easy to use, and it's hard to get a bad sound
out of.

Contrast that with the Waves L1 limiter. It's aggressive and will
clamp the sound down, but it starts making the sound of the track hard
and annoying very soon, and very often.

The Renaissance Compressor will give you the smoothness you need
without the harsh sound added to it.