My favorite Dithering Hardware and/or Software
As of this writing, there are more than a few choices of
dithering to pick from, and dithering is actually appearing
in far more places than ever before, making it even easier
to misuse and abuse this critical stage of sound production,
reduction, and reproduction. So, after countless hours of
comparing track after track of a wide range of material
dithered with Waves L3, Saracon, Apogee's UV22, and several
others, some clear points, in my mind at least, have
emerged.
My Favorite Dithering Test
Below, you’re not looking at anything other than Noise
Floors of the music in relation to frequency. In other
words, using the POW-R3 as an example, the noise floor,
after dithering, sits at about-140db across most of the
sound spectrum, but drops to -165db around 3K, and
sharply increases to about 105db from 12K to 20K. Since
our ears are not too sensitive to noise in lower
frequencies, very sensitive around 2K – 5K, and and less
sensitive at higher ones, the noise curves are created
to “hide” the noise created from reducing word lengths
from 24-bit to 16-bit in places our ears don’t hear.
One of the countless tests I ran at the studio, this is
the one that sticks out in my brain most, and the one
that also seemed most relevant to one of the biggest
questions in relation to dithering and mastering: It's
what happened when I dithered a 24-bit/96K stereo audio
file using Waves L3 Multimaximizer internally in Pro
Tools and also with the Saracon externally after a
Bounce to Disk.
Out of all the dithering hardware and software I've
tried and/or used in practice, those two are head and
shoulders above the rest that are available, regardless
of the type of program material I might be working on.
So, that's why I only include these two here in this
example.
And honestly, when the rest of the pieces in the
mastering chain, from the final mixes, to the transfers
and up-sampling, to whatever tweaks might be added
either digitally or via analog are applied properly, the
difference between the L3 Ultramiximizer Dithering on
IDR, 16-bit, Type 1, and Normal and the Saracon on its
standard 16-bit/44.1K POW-r3 dithering algorithm were
subtle at best.
When I have the luxury of A/B, and with a 3rd party
pressing the buttons, I did choose the L3 every single
time, but only out of personal preference. The L3
seemed slightly more open and airy, with a touch bit
more clarity on the high-mids. But, the Saracon
seemed just the slightest bit warmer and fuzzier...but
only in the most delicate of nuances, and truly nothing
that would seriously alter anyone's perception of the
final product, regardless of the dithering used.
So, below are two images of a dithered sound file of
white noise. The left is the Saracon, and the
right is the L2in IDR Ultra mode. Notice how both
"hide" the noise in almost the same places as each
other, with slight variances in the curves near the
upper-mids. My analytical mind tells me that these
differences are so slight, that my brain shouldn't be
able to detect them, but in test after test, the above
descriptions fit virtually every time.
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Now, what I did was take both dithered files,
putting one out of phase with the other, and
matching levels up perfectly. What remained
was only the artifacts left behind by the dithering,
and the combined dithering noise that was added to
each file during the dithering process.
What you see is exactly what one might expect...a
combination of the 2 above curves, proving to myself
that each dithering option performs extremely close
to the advertised curves of each. |
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And below is the left channel of each stereo file
put next to each other. It's a low resolution
image, but even from that you can tell that the
differences between the files are quite subtle, with
the L3 file on top having the ever-most slightest
more jagged edges here and there. |
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So, my point about all of this is only this:
Don't obsess over the details of any one of the
steps in the chain when it comes to mastering,
especially when it comes to dithering. If
you've got good mixes and you go to someone you
trust knows their stuff, the differences that each
different dithering algorithm, as long as it's not
the built-in dithering within Pro Tools, will not
make or break your mixes, and in my opinion, largely
comes down to a question of personal preference .
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