VST DAW Tips for Stereo Compressor—Limiters


The BEHRINGER AUTOCOM® MDX-1200 Stereo Compressor—Limiter (with Enhancer) 
is a personal hardware favorite of mine I have been using in my DAW Studio since 1996.

Perhaps the most misunderstood (and also mis-used) signal dynamic processing device in any recording studio gear arsenal is the Stereo Compressor—Limiter

There is a very good reason WHY a -hyphen- appears within the name describing this device. That's because it is actually (2) separate effects processing modules packaged as one rack unit. When in the hands of an unskilled novice, any attempt in using one can and WILL produce horrible sounding results!

So, what are Stereo CompressorLimiters and what do they do? 

Essentially, these units are rack mountable hardware amplifiers that specialize in reducing studio recorded (or play back) sounds without sacrificing volume gain. They accomplish this sonically by smoothing out the dynamic range differences heard by the human ear from between the softest to the loudest of sounds (3dB to 15dB ranges).  

Since all sound sources have different dynamic ranges or peak-to-average proportions, without  Stereo Compressor—Limiters, it would be difficult to control sounds that are recorded too loud, too soft (Compress) or at such intervals where occasionally a recorded track peaks at a certain point that is undesirable (Limiting). In particular such as with the human voice or musical instruments

Beyond this, Stereo Compressor—Limiters also provide many other technical/resolve solutions that are constant and on-going in any recording studio environment as well. 

Stereo CompressorLimiters in DAW as VST Plug-ins:

In DAW, the virtual reality PC Screen counter parts to Stereo Compressor—Limiters (such as other effects like Graphic EQ's/ Reverb/ Digital Delay/ Stereo Flange & Chorus, etc.) are all  known as DSP's (Digital-Signal-Processors).

DSP is a broad general term used to describe "the entire family" of virtual effects processors that are available in DAW for users. However, individual effects devices from these DSP groups are known as VST Plug-ins.

VST (Virtual Studio Technology) is a native plug-in standard developed by Steinberg. This is probably the most common plug-in format and is supported by most virtual instrument developers. VST's can be used on both PCs and MACs but compatibility is dependent on the host program being used (i.e.: ACID Pro7® for Microsoft a/o  
Pro Tools 9® for Macintosh).

Screen Shot Tips Using Stereo CompressorLimiters / Graphic EQ's / 
Stereo Wave Editing VST Plug-ins:

The Following is a series of Screen Shots depicting how particular VST Plug-in techniques can be used to solve typical mix-down problems I describe as:  

Smoothing Out Frequency Distortions Without Sacrificing Global Volume Gain at Master Console using ACID Pro7® in Windows for DAW with the following VST Plugs-ins:

(Double click any image once or twice to see better.)
> Use Browser Back Button after viewing to resume this blog study link page!

DENSITY MKII® VST Stereo Compressor Limiter.


What it does:

DENSITY MKII® was primarily designed to work in a typical stereo audio group mixing situation or for summing and to glue all things together in an unobtrusive way. It is based on Vintage 1960-70's style Vacuum Tube technology often used by Studio Mastering Engineer Greats like GEORGE MARTIN (the Beatle's) or JAN HAMMER (*also world re-knowned keyboard player of  the MAHAVISHNU ORCHESTRA and THE JAN HAMMER GROUP).

In my own experience using this VST Stereo CompressorLimiter, I've determined that this type of plug-in is best suited for chain plug-in insertion points within an individual DSP track a/o Event Window (instead of running it for global volume at Master Console).


Tips & tricks: 

  • Use the limiter mode to manage difficult studio dynamics.
  • That's because it does not operate as a “brick wall” design.
  • Instead, it offers a more "strict handling" of dynamics. 
  • Utilize the RANGE functions for each channel.
  • You do this by working in M/S mode—
  • This makes it easier to get M/S compression just right.

 Wave Hammer® VST Stereo CompressorLimiter.


 What it does:

Wave Hammer® was also primarily designed to work in a typical stereo audio group mixing situation or for summing and to glue all things together. But, in a more obvious and much different way than a VST Plug-in such as DENSITY MKII® just shown earlier. 

Inserting Wave Hammer in varieties of Stereo Compressor—Limiting mode (for global volume at Master Console) actually improves end results better for a VST like DENSITY MKII (that's inserted within a track/event window for DAW).

Tips & tricks:
  • Edit non-destructively with no more waiting to process further instructions.
  • Support 32-bit/192 kHz audio files larger than 4 GB for NTFS.
  • Open QuickTime, MPEG, WMV, WMA files & save to all formats.
  • "float" windows to open, close, dock & stack as desired. 
  • Use Explorer-style Plug-In Manager as VST for drag & drops.
  • Integrates easily from ACID Pro 7® into Sound Forge Pro 10®.


Putting My Money Where My Mouth Is About All This!


Let's take a closer look at how I often use Wave Hammer as a VST Stereo Compressor—Limiter to correct certain frequency distortions without sacrificing global volume at Master Console for mix-down. But first, what I have in mind is to graphically show you one of my existing multi-tracked songs already mastered correctly in stereo many years ago. I'll be using ACID Pro7® for Windows to demonstrate all this in DAW.


I'll simulate the existing wave file of it and then exaggerate frequency distortions by jamming the individual track/event window volume faders up to the hilt. Then, I'll further double "all bets" by duplicating this same wave file and frequency distort a copy of that too (to appear underneath the first one as Track#2 in event window) for you to see as follows:



(Double Click image once or twice to see better).
> Use Browser Back Button after viewing to resume this blog study link page!


In the above screen shot, although I've intentionally hidden the Master Console faders for dramatical purposes (normally located at bottom of this ACID Pro7® program in DAW), we can visually see how everything has distorted verfiabley. My simulation suggests that the "smoothness" hoped for regarding Global Volume Gain at Master Console has been achieved unsuccessfully.


At this point, it's important to stress that this problem occurrence is potential throughout all stages of multi-track recording—and at any time. Regardless if it is a single track "take-down"  recording of an individual instrument or a series of completed multi-tracks ready for mix-down mastering (as just shown above), any introduction of frequency distortion must be dealt with effectivelyand at once!


Here is how a remedy to this problem should look like using Wave Hammer®:


(Double Click image once or twice to see better.)
> Use Browser Back Button after viewing to resume this blog study link page!


In this new view above, we can now see Wave Hammer® inserted at bottom of the ACID Pro7® DAW program to right of the Master Console group faders. We also can see that correct Global Volume Gain for "stereo mix-down" has been accomplished!



Side Chaining Using Rack Stereo CompressorLimiters & Graphic Equalizers:


Sometimes, depending on the situation, a variety of "specialized" techniques can be applied to address frequency distortion a/o overt volume attenuation problems by using rack Stereo Graphic Equalizer's outside of DAW. 


When these units are "side chained" into rack Stereo CompressorLimiters at the hardware level, some very impressive corrective protocols can occur called "ducking."


Top of my studio rack shows (2) Stereo Graphic Equalizers. The bottom one is a  FOSTEX Model 3030® 10 band Stereo Equalizer. However, the thinner one above the Fostex is an IBANEZ GE1502® 15 band dual 2/3 Octave Stereo Equalizer with switchable HPF (*high-pass-frequency) controls. The Ibanez unit's rear panel contains Side Chain Input capability for "ducking." These rear configurations can also be interfaced into Patch Bays shown to be routed into Stereo CompressorLimiters with Side Chains located elsewhere (not shown in this rack).


What does "ducking" mean and what does it do?


The Legendary Howard Cosell. Master at "ducking" both On and Off The Microphone!


The term "ducking" is where rack Stereo CompressorLimiters and Stereo Graphic Equalizers (and other DSP devices) can be back panel wired between each other to technically  "detect"  and handle difficult sound frequency distortions a/o overt volume attenuation problems in concert together. 


The term itself originated initially from the Sports Radio Broadcasting Industry. If you are an avid sports fan, chances are you've heard voice announcers rely on this technique while covering huge outdoor arena events live for Radio or TV using microphones. As large crowds roar accordingly (drowning out the announcers voice), "ducking" ensures that every time that happens, "detection devices" (like CompressorLimiters chained to the microphone) automatically "push down" or "duck" the back ground roar allowing the announcers voice to still be heard speaking clearly. So, that you (as the media listener) can enjoy hearing all aspects about what's going on back at your home or office correctly.


How "ducking" is used in various Recording Studio Environments:

In the recording studio environment, a good example of "ducking" being used is where a sound engineer has multi-track recorded (separately) a singer with a very loud voice. The audio engineer may be certain that the track recording of this performance was executed correctly. A quick play back  seems to assure that everything sounds in order. He (or she) thus proceeds moving forward with the rest of the session involving the other musicians appearing on this mix. Meanwhile the singer (who is from out of town), is finished recording their parts. They leave the studio to fly back to wherever it was they came from many hundreds or even thousands of miles away. 


Later at mix-down (when EVERYBODY who recorded on this session is gone), our sound engineer realizes (in horror) that the "out-of-town" vocalist's track mix was recorded  incorrectly and very loud after all. So much so that subtle, but nerve racking, frequency distortions have suddenly also appeared where they did not seem to be present before! Usually, traditional remedy applications using board console a/o rack  equalizers would help solve most of this audio engineer's problem mentioned. But, not all of them regarding the additional frequency distortion issue also described earlier. 


However, in conjunction with a good Stereo CompressorLimiter and Stereo Graphic Equalizer unit "side chained" together, this sound engineer stands a very good chance pulling off a turn around that's nothing short of an audiophilistic sound miracle in itself. But first, here is a brief description about Stereo Graphic Equalizers as stand alone devices.


What is a Stereo Graphic Equalizer and what does it do?


Normally, Stereo Graphic Equalizers are used to change the stereo sound frequency spectrum familiar to the human ear. For example,  if a mix sounds  "too bottom ended and dull" dialing out less bass and adding in more high frequencies to brighten the mix can be implemented. So, that everything sounds more normal as expected. As shown here in this familiar view of one as a VST Plug-in:



20 Band Graphic EQ® VST Plug-in for Microsoft® from Sony Creative Software, Inc.



What does "Side Chaining" mean and HOW is it used?


Many rack Stereo Graphic Equalizers can also be used for what's known as Sound Frequency Detectors when "side chained" into rack Stereo CompressorLimiters. When this happens, the Stereo Graphic Equalizer no longer traditionally responds to "audio sound frequency ranges" as explained and shown above earlier. Instead, it now becomes what's known as a "wave frequency threshold detecting device" and is "Master Controller." Consequently, the Stereo CompressorLimiter unit is now known as a "Slave."


In this way, a Stereo CompressorLimiter can be used by The Stereo Graphic Equalizer to fine tune complex and vastly hidden frequency distortion a/o overt sound attenuation invariency issues. These types of issues are forever constant and certain to arise during any recording studio session. However, not all rack Stereo CompressorLimiters a/o Stereo Graphic Equalizing devices can function in this manner. Unless they each have Side Chain INPUTS and OUTPUTS at rear panel for combination single a/o dual channel line feed runs, "ducking" will not be possible.


Such as this simple illustration demonstrates:



  ► Click Back To Home

All You DAW It Here Blog Contents & Original Music © 2010-11 By MARTIN HENRY.
All Rights Reserved.
All AFFILIATE DAW LINKS: © Protected By each article web author(s).
All Rights Reserved