@jasensmith said:

How would you use it in a Classical or orchestral setting?  As an overall compressor, like for mastering, or on individual tracks, or both?

Hello Jasensmith

First of all for all of you who never used the parallel compression a short manual how to do it:

1. You need  to copy the track which needs to be compressed so that you have it twice.

2. One track gets a compressor the other track gets nothing.

- The green curve below shows the track without a comressor (in is out)

- The red curves shows the channel with the compressor. A "very soft knee curve" is used here.

3. So use a ratio of 4 - 8 together with curves as we have them in the picture. Not all compressors are offering such curves.

    The attack time can be longer than we normally use for rock and pop so 5-15ms instead of 0,1-1ms. Try different release times. Start with auto or ~200ms.

4. Sum both channels with a Bus - channel for example.

Important: You need to take care about the phase. You should have absolutely synchronous signals

What happens now?

Within the region A=light blue (low signals) we get an addition of the Signal of the green and the red track. The louder the signal the more we have no more addition (region B, light orange).

And finally with loud signals we only get a signal from the "green" channel.

This means that quiet signals will sound louder (we get it twice) and louder signals still have the original volume.

This way you don't cut or compress the signal but you make the quiet signals louder = less dynamic over all which can be usefull in classical music as you can read above.

For classical music it is enough to become quiet signals 3dB... 6db louder that's enough.

The opposite would be: Compressing the main signal (-3...-6dB). But this can kill transients or it can lead to pumping signals...

Another way could be to use both "systems": Just a little compression and just a little "up-leveling" with parallel compression.

In classical applications I always use the compressor very very carefully or I use one behind another.

I often use the parallel compresion in the output (mastering) channel.

Finally 3 things:

A) A lot of compressors have a dry/wet knob. Then you don't use a second copy of your audio signal.

B) If you want to use the parallel compression together with classical music you should look for compressors which can offer such "round"-knee-curves. I often use this guy here (pdf 10MB).

C) We normally don't have the problem of such loud and in the meantime also quiet signals when we are using samples because they all are well recorded for us. So the use of compressors in connection with samples may a bit differ.

All the best

Beat

Beat,

Thanks again for your insight.

Parallel compression can also be used to altar a sound a little which means that it could be used as an effect as well (Dropping the threshold and lifting the ratio).  But unless you're doing some avant garde kind of stuff I don't know if this "effect" application would be relevant in orchestral settings.  Personally, I've been known to expirement a little by feeding horn ensembles, strings, choirs through various guitar amps just to hear the results.  Every once in a while I am delightfully surprised of those results.  Of course, that's part of the brillance behind using samples.  Live players might not appreciate my sonic mangling of the hard earned sounds they produce.  

I realize that you are not suggesting to use parallel cmpression as an effect but your detailed explanation gave me some ideas.  This certainly is food for thought.

Thanks   

@jasensmith said:

I realize that you are not suggesting to use parallel cmpression as an effect

Hello again

As I remeber so far I never used "Parallel-Compression" until now in connection with samples and their mixes.

Beat

edit:  (Probably) never compress orchestral music.  The most extreme dynamic range is to be found with the symphony orchestra and this principle must be adhered to with VSL samples.  Though many people use them in a "quickie"  way and then use  tricks of mixing.   Vienna Instruments has the tools needed for realism, if you take the time to use them.  You can adjust dynamic range of every instrument separately, and adjust overall levels.  Those two factors eliminate the need for compression - unless it becomes an issue of "fixing it in the mix." 

Unless you are working in the commercial field, and then you pretty much have to.  [;)]

DG

I've seen, heard and done both extremes (and everything in-between): Recordings without any dynamic processing, and recordings with lots (and I mean: LOTS) of processing in any respect. I can assure you that the quality of the result has no corellation with the use or the absence of compression. ;-)

Kind regards,

Never mind, I will just avoid further comment. 

 no, maybe I will comment more  - I did overstate it earlier.  However I like at least in principle the idea of not using compression because it is the reverse of what the symphony orchestra has, which is the most extreme dynamic range of any musical ensemble.  

Also, I have thought about (but not yet seriously done) using compression in a somewhat "artistic" way, that is by applying it to instruments that tend to be more accompaniment, and NOT applying it to instruments that are playing more main lines.  So with strings for example, you might use compression on basses and violas, and flatten their dynamic range, but not use it on violins and cellos, which would make them appear and disappear more noticeably in comparison and "sing out" more prominently.  Also, it would stop basses from disappearing in a mix which can sometimes happen.   Likewise, with woodwinds, using compression to keep them audible, but NOT using it with brass or percussion since they always have enough volume to be heard.   I haven't really done much with this approach though...

Lots of reasons not to compress, and two reasons to compress:

1. an artistic purpose which is more important in your particular project than realism; and
2. if the listening environment is expected to be noisy, in order to keep the quiet parts of your mix above the background noise.

What we have to keep in mind that there is a HUGE difference between an orchestra playing live in a hall and a recording of the same piece of music.

Look at it that way: Listening to the live orchestra is like attending a theatrical perfomance. Listening to a recording is like watching a movie. Film and theatre have convergences, but I hope that we all agree that they are _not_ the same art form. Not many people would watch a movie which has been made with only one single camera shot, from one single perspective without changing angles, without additional light, without color correction, without edits, and so on. For many genres it is common to use CGI. ... I think you get the point.

The same is true for recorded music, no matter whether it was played live or created virtually. Most of the time, a "pure" recording is actually quite boring. We have to create points of interest for the ear which wouldn't appear in the "real world". Artificial changes in the acoustic "perspective", the "colors", the "lighting", and so on.

Sometimes a simple rebalancing is all that's needed. But more often than not, we have to recourse to additional methods and tools, like edits, EQs, filters, dynamic processing, articficial reverb, modulation, synthetic sound sources, ... Compression is just one of them. I wouldn't say that you can't make a good recording without it, but I wouldn't hesitate a second to use it whenever I get the feeling that the result will benefit from it.

Kind regards,

That is a fantastic comparison Dietz!  I love that concept which is very complex if you continue to think about it.  It is really true and also a great way to give one ideas about how to work.  Also, bachrules has a good point about the artistic reasons. 

Jasen smith mentioned the old classical orchestral recordings -  an example of something that is similar to compression, but not actually compression, can be found in later great classical recordings which are exemplified by the London FFFR recordings of Mahler done in the 70s.  This includes the recording which has been the "greatest recording of the greatest performance of the greatest composition" of all time - Mahler's 8th conducted by Solti and played by Chicago symphony, recorded by London.  I have the LP album, also a CD reissue.  That recording is really great, and has a lot of individual miking which is somewhat similar to compression in that a flute solo will certainly be louder when heard alone and the engineer adjusts that track upward, compared to its level in the whole ensemble, but is not actually compression. It is a form of "manual " compression.  But the overall impression of such a recording is really great and exactly the kind of thing Dietz is talking about.

Riding the levels has been a conventional, every-day task for an audio engineer since the earliest days of (orchestral) recording. An important part of the whole "compression"-concept we got used to goes back to this exercise. The other influential factor was the need for taming - read: limiting - the occasional loud hit which would destroy an otherwise perfect take. - All the ideas of coloring individual tracks and/or "glueing" them together by means of compression became popular much later.

Kind regards,