Vestman Mastering - Separations are Different than Stems

Separations are different than "stems"

The term "stems" comes from the metaphor (or example) of a tree - the stems all unify into the trunk. The trunk is not a stem. The final 2-track mix is not a stem - it's a stereo mix. Tracks used prior to the stereo buss are stems. Tracks recorded after the stereo buss are either stereo mixes or Separations (that may contain processing that is unique to the stereo buss). Separations are a clearly defined set of stereo tracks intended for mastering. The stereo mixdown is included in the Separations format as either a reference or as another source from which to master.

"Stems" are for a variety of uses.

• Stems in mixdown are anything and everything prior to the master stereo buss output... single tracks... multiple tracks... etc.
Different stems/tracks often send signals to effects processors (such as reverbs) that are shared, but the aux returns from these processors are commonly located elsewhere on the mixer and are therefore not exclusive to one stem or another.
• Stems are used in video, film, 5.1 and live sound production for remixing (anything from subtle to dramatic changes). Stems can be stationary, automated, processed, muted, grouped, edited and more.
• Stems are used for analog summing "outside the (computer) box." Outboard reverbs and effects may return to the final stereo path via separate channels on the "box." Also the stereo buss insert can put a "shared" compressor or processor over the stems/returns/etc.
• Stems have been used in mastering, but all of the stem variations can make this complicated... or simple (for example if you were just adding one stem into the stereo mix to increase bass) in order to correct balance issues. 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.

• Separations are a selected number of tracks that form a portion of the final mix. Separations typically use the stereo processing that is on the master buss ouput. A full set of Separations equals the approved final stereo mix when they are recombined.
• Separations alwasy include any related aux effects returns, plug ins, automation draws, mutes etc.
• Separations are often fewere in number than stems because they are primarily NOT intended for dramatic alteration.
• Separations are complete because they include the 2-track stereo mix as a reference to honor the artist's original vision - as well as for use in mastering if the client prefers. Both "flavors" increase the possibilities for the final master.
• Separations are for refining - like traditional mastering - but adding the ability to restore certain elements (drum levels for example)
• Separations reduce the worry associated with acoustic masking of details in non-ideal mixing environments.
• With Separations, you tend to orient your thinking more similarly to the way the mastering engineer listens. By knowing that you aren't locked down to two tracks, you mix with a slightly different purpose - to balance your elements correctly and musically.
• You tend to let go of that "last minute obsessing" knowing that the mastering process will accommodate your final musical intentions. You will never get the dreaded "go back and remix it" message from the mastering engineer, and you won't need endless alternate takes!
• Separations can take advantage of both digital and analog tools -- possibly rivaled only by ideal engineering, consoles and ideal acoustic environments. This format 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.

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.