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Separations are Different than Stems

The term "stems" comes from the metaphor (or example) of a tree - the stems all go into the trunk. The trunk is not a stem. The final 2-track mix is not a stem - it's a stereo mix. The stereo buss defines the difference between the two. - it's a component of the mix or the Separation

Stems are intended to be summed to a stereo mix which is intended to go to mastering.

Separations are intended for mastering. It's a way to call out a format that is specific, predictable and includes the stereo mix. When people think stems, they don't think to include the approved stereo mix as a reference (or as an alternate source for the mastering).

• Any tracks before the stereo buss are stems
• Tracks derived after the stereo buss are stereo mixes or Separations
• Stereo buss processing is not a component of any stem • Stereo buss processing is embedded in the Separations
• Stems are structured in a way so they can be subtly adjusted or be dramatically altered in the creation of the final stereo mix
• Separations are structuured for subtle, more "global" enhancements that look to the completed stereo mix as the essential reference point
• Stems can be hugely different - aux busses, groups, tracks, mono stereo, 5.1, live sound groups, tracks for film, etc.
• Separations call out a specific format for a specific purpose: Mastering for a final stereo release
• Different stems can use aux sends to access different reverbs or special effects - those reverbs or effect returns are not part of the stems • Separations are all-inclusive - any effect returns, automated moves, triggered sounds or side-chain processing is included in them
• The idea of "stem mastering" conjures up the idea that the mastering engineer is going to be remixing in the mastering studio • Separation Mastering uses the stereo mix reference to ensure that the original stereo mix is referenced. 
• Stems are not used to restore a mix, they are used to create it • When mastering loud audio, the drum separation can be raised to offset loss of transients in order to restore the intent of the original mix
• The unlimited form stems can take imply that continual, exhausting mixing will take place in a facility not designed for mixing by a mastering engineer who doesn't specialize in mixing on a full time basis.  • Separations imply that a limited number of tracks will target one goal: a fully optimized stereo mix brought about using the daily techniques, equipment and philosophy of the experienced mastering engineer.

Separations define a clear-cut format and lessen the possibiliy of error

• Stems have been used in a minor number of big name releases in years past. (Here's a visual example from 1998 when I did a last-minute rebalance of a vocal in the mastering of Juice Newton's "American Girl" CD.) But these stemed-out projects had no standardized form because the engineers involved were individuals with specific production goals. Today, the huge number of independent studios and leading mixing engineers can benefit from a standardized format defined for mastering.
• A full set of Separations equals the approved final stereo mix when they are recombined.
• Separations eliminate the need for endless "alternate" stereo mixes

• Separations alwasy include any related aux effects returns, plug ins, automation draws, mutes etc.
• Separations include the 2-track stereo mix as a reference to honor the artist's original vision
• Separations reduce the worry associated with mixing-room acoustics that can mask the sonic details of a mix
• With Separations, you tend to let go of that "last minute obsessing" knowing that the mastering process will
accommodate your final musical intentions.

• Separations can take advantage of both digital and analog tools -- it can can "level the playing field" for engineers, producers, labels and artists who don't have time for trial-and-error projects.
• Separations just make sense.

Back to the article on Separation Mastering

What if your mix is perfect without Separations?

Our goal is to achieve your goals. If you're very happy with your stereo mix, we can fully recommend using 2-track stereo mastering to enhance what you have! 

Different flavors of sound are not right or wrong -- any more than chocolate and vanilla are right or wrong. 
"A-List" engineers often utilize a large format console, exotic gear, or perhaps analog summing boxes and great D-A converters - all of which contributes to mixes that are amazing from the first note. Sometime a more dry, "glued-together" sound is preferred over a wider, more distinctly stereophonic sound.

But consider this: Most A-list engineers are already mixing with subgroups even when the 2-track mixdown is the only intended source for mastering. Given the cost and difficulty involved in perfectly recreating a mix after everything's been dismantled and reset, archiving stems and Separations make perfect sense as a back up plan when BIG bucks are being spent.

Interesting: Our ability to "think outside the box" with Seprations has set us in the direction of looking a little deeper into methods of processing audio.  Many of the time-tested heavies in mastering like Bob Ludwig and Bernie Grundman get the easiest work, because the big labels have the budget for monster mixing engineers and studios.  Therefore, they don't have to look as deeply to get great sound - it's just there already. 

Since we've worked harder to find new ways to "level the playing field," we carry our experience forward into the work we do with stereo mixes.  Our more innovative sound processing ideas work for traditional 2-Track mastering.  Try us for your stereo mixes - your CD will sound amazing because we go beyond normal mastering applications.  Contact us....

However if you have a perfect mix and still want the flexibility of just adjusting the vocal level and nothing else, we will simply leave the Separations set to unity gain - use only standard outboard processing - and adjust the vocal level if required.  (Or just make two simple instrumental/ vocal separations!)

Quick tips!

Check your tracks for polarity.  Here's an advanced tip - you should be able to look at your tracks - the kic drum in particular - and see that the "leading edge" of the kic drum starts from the center of the waveform and goes up.... then down.  If your waveform goes down first, insert a plug in that can invert (or flip) the absolute polarity (also called phase).  Listen to the sound.  If you feel that there is more fullness and punch when the track is inverted, then you have corrected its polarity.   If you feel the sound gets slightly thinner and the top end (treble) gets a bit more harsh, you've flipped the polarity but it's not correct. 

Check your mixes for polarity.  Same thing.  Put your stereo mixes into a DAW program and insert a plug in that flips the polarity.  If your mix sounds fuller, more punchy and smoother in the upper mids and highs, then you have corrected the polarity.  If instead the sound gets a little thinner and less pleasant in the treble range, then your mix was correct before flipping it.  The leading edge of the waveform is pushing when the polarity is correct.  It's pulling when it's not.  Yikes but it can be tricky on some systems... why?  Because some playback systems have polarity issues in their components, cross-overs etc.  If you hear no difference at all, stick with your standard mix setting and we'll check it out. 

It will take more time for you to make your Separations. Use the 3-D's - Document, Describe and Detail. Be sure you are organized, because good file folder management helps the load-in process go much faster. Document your track layout and double check to be sure all tracks are accounted for, no tracks are duplicated, reverbs and effects are included in the respective Separation tracks.  The more organized you are, the less likely that mistakes can occur.

Leave headroom in your stereo mixes - slamming to the max isn't the best way to go. If you can, remove your master fader for better sound (unless you are using plug ins across your stereo buss that are important to your sound). Your mix shouldn't create digital overs (clipping) when your master fader is set at -0- unity gain.  Particularly when your system is 24-bit, it's better to have your peaks top out at -2 to -3dB on your stereo mix buss!  Remeber, don't raise the gain of the tracks when you make your Separations!  Everything should stay exactly as it was when you mixed.... just separated.

Check to make sure you've included every musical element in your Separations that is contained in your mixdown! When it comes to kic drums, use reverb and/or big room sounds carefully because mastering up to today's hot CD levels can add sustain and presence to that room tone - which can blur the overall sound. If you want that big John Bonham room feel, you may want to separate your kic (in stereo) from the rest of the kit. That way if the verb gets too heavy, it can be trimmed without compromising the other drums. By the way, a key to that great Led Zepplin sound was the fact that vinyl wasn't slammed the way CDs are today - leaving an openness and punch that's still awesome 30+ years later!

If you are mixing to a Masterlink, stand-alone CD burner or other "wild" mixdown format (non-exact start and end times) instead of a computer "bounce" - include a sharp click, tic or other line-up cue at the beginning of each separation. Preferrable is a metronome or other pure-wave sound with a crisp, immediate front edge. A kic, snare, stick-click count-off is fine, but a bass note or vocal cue makes Separation-syncing more difficult!  Be SURE the EXACT same click is used for each and every Separation!!!

Display the LEAST amount of visual graphics on screen when you are recording your Separations. Once you're done setting the pan position/automation in your mix, remove the pan pots (visually) from your mixer display. Same thing with your fader meters, I/O displays, mute/solo/record button displays, plug in windows, etc. The fewer graphics, the less your computer's processor has to work.

Do your homework! Listen to CDs and find the sound you love the most. Note the musical arrangements on your favorite CDs to hear how much space, sustain, reverb, bass, vocal, etc. "defines" your taste. Example: If you love the sound of CDs that have sparse instrumentation and close-miking techniques, check that yours isn't full of sustain, room sound, reverb and mulitple layers of overdubs that are crowding the "air" in your tracks. If your favorite group has a bass part that lifts between notes and your bass part is all sustain, it will add some challenges to our ability to achieve your sonic goals. Separations give the ideal way to steer in an ideal direction, but they don't replace the car! Bringing in a reference CD or two with your session can be an easy way to show us the sound you like.

© Copyright 2000 - 2011 Vestman Mastering
Created 9/14/09 modified 1-2011

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