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Some of you may be
familiar with the need to time compress (slowing down or speeding up audio)
or pitch (change the key) of audio tracks. If you've used Sound Forge's
Acid, then you've already used a type of audio compression or expansion. The
problem with Acid is that once you stray too far from the original BPM
(beats per minute), you quickly hear an echoed chugging sound and the
results are typically amateurish. Ok so how do the big boys do it? (and
we're talking multi-million dollar studios) The answer is the definitive
Pitch 'n Time by the New Zealand based Serato Audio Research.
Pitch 'n Time is THE program for changing tempo and pitch of audio. A quick
bit of research and inquires of some top remixers and studios, confirm that
there is no other plug-in / program designed for this purpose. (Time
Factory, a stand alone program, is becoming difficult to find) Pitch 'n Time
can handle anything from a solo vocal track to a full mix! So why do you
need such a plug-in? I'll look at it from a music production / remix stand
point of view.
First, you'll never be locked into the BPM's of the originally recorded
material again. Pitch 'n Time allows a flexible tempo change in percentage
or tempo change and offers a huge range of possibilities (50% to 200% of the
original which is more than enough to take it from ballad to club hit!) All
the while it maintains the original key (or you can change that at the same
time as well). Simply enter the BPM's of the source material (Note if the
tempo of the selection is defined within ProTools, then the input BPM is
filled automatically - thus the bars and beats field is calculated
automatically as well, but I wish Serato would add an automatic BPM counter
just the same) then enter the new desired BPM's, and within minutes (for the
average 5 minute track, shorter for samples and loops) your audio is
magically transformed into the new BPM's. And the real magic is that you
can't hear any audio artifacts. A true professional result indeed! |
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Pitch 'n Time achieves
this transformation through the use of Serato's own proprietary technology
called "Intelligent Sound" which is based on Human hearing rather than a
mathematical calculation. According to Serato "It may seem obvious, but the
perfect time stretch is one where the output sounds the same as the input,
just faster or slower. The key word here is 'sounds', which means the
problem isn't about waveforms or kilohertz - it's all about hearing. Serato
Audio Research has developed a sophisticated model of the human auditory
system. In a sense, the software "listens" to the music, performing a
sophisticated auditory scene analysis. Only by listening can it determine
what 'sounds' the same, but faster or slower. Normally using such a
sophisticated model of the human auditory system would be computationally
prohibitive, so novel mathematical methods had to be developed by Serato to
speed up this process in software."
OK now that we've established that we can do just about any kind of tempo
changing, Pitch 'n Time goes a step further by allowing you to change the
tempo in different ways (should you have the need). We've already covered
the basic "Fixed Time-Stretch Panel" where you will do most of your work,
but Serato went a step further by including a "Variable Time-Stretch Panel"
This provides a more sophisticated interface to the time-stretching function
by allowing the user to edit a tempo automation graph. OK what does this
mean to you? Here's a real work example; I recently used Pitch 'n Time to
edit the tempos of individual tracks on the forthcoming GlobalDance
Underground compilation album. I needed to ramp up
the tempo from the beginning of the song to the end in order to mix with a
faster tempo song following it (thus the classic DJ build up). All I had to
do is open the Variable Time-Stretch Panel view in Pitch 'n Time, enter a
starting BPM, select a place within the track to start the BPM increase,
designate a second point at the desired ramped up final BPM, allow for an
area of steady BPM's at the Outro, and voila, Pitch 'n Time figured out all
the rest! The result was exactly what I needed. (Note that if you're
processing stereo audio, you'll want to be sure you click the MultiChannel
mode before processing. I found this out the hard way and the results are
typically unacceptable!)
Lastly, Pitch 'n Time gives us a "Morphing Time-Stretch Panel" which again
provides a time-varying time-stretch facility. This panel is useful if you
need to control when things happen, rather than how quickly. Just drop
markers on the audio and move them where you want them to go. Pitch 'n Time
stretches and squashes the audio to fit!
So that about covers the "Time" portion of Pitch 'n Time, now we'll take a
look at the "Fixed Pitch-Shift" portion. This is also as easy as pie
transformation. Simply enter the key in which the audio was recorded at,
enter the desired new pitch, (50% to 200% of the original) and hit process.
The result, once again, is flawless. So you can record a vocal track at a
comfortable range of the singer, then pitch it to the key of the song for a
dramatic effect. You can even do some weird effects based pitching that can
turn a kick drum into a tom tom or a voice into a monstrous sound effect.
(Too bad Serato doesn't incorporate a kind of pitch correction feature for
complete vocal processing in one package?)
Serato also threw in a Varispeed Mode which forces the pitch shift to
precisely match the time stretch at any point in time. This creates the
classic varispeed effect allowing you to make great sounding record / tape
speed-up and slow-down effects.
With a plug-in as easy to use as Pitch 'n Time (there is little or no
learning curve!), and with as professional level of results, it's no wonder
that Pitch 'n Time has quickly taken over the market in audio time
compression and expansion. Although at around $700, it costs as much or more
than most stand alone sequencers, and the initial expense can seem daunting,
but look at it as more of an investment in your career. Pitch 'n Time does
basically two things, but you will quickly find more uses for it. I
originally needed it for compressing and expanding entire mixed
tracks, but I quickly found myself using it on individual loops and audio
within the mixes themselves quite frequently!
Bottom line, you will NEED this plug-in some day. If you're a producer, you
will need it for it's flexibility. (I've heard the results of mixes where
time compression and expansion were handled poorly, and by using Pitch 'n
Time, your risks are minimized if not removed all together.) If you want to
get into remixing, by all means you're absolutely going to need it to work
with the vocals and various splits you'll receive from the labels.
I've been living with Pitch 'n Time for a couple of months now, and I can't
see how I ever got by without it! Simply a must have for all aspiring
producers and remixers looking to add that professional edge! Just ask
anyone who works in professional audio and chances are that they use it! Get
it now before Madonna calls you and asks your for a remix! (OK the chances
of that are pretty sparse, but you get the point!) |
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