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Many engineers go
through the experience of happily completing
mixes on a digital audio workstation (DAW) and being disappointed by
how low the overall volume on a CDR copy is when compared with a
commercial CD. Yes, mastering takes your mix to that "next" level, but
in the meantime wouldn't it be nice to eliminate the doubt that
comes along with those level differences? Correct meter settings can
help a lot especially when you have digital peak meters and analog VU
meters to look at.
Q) Some engineer prefers to have their
signals as close to digital zero as possible - what do you recommend?
-Jarno (from Finland)
For both
tracking and stereo output levels we suggest peaking at -2
dBFS (minus 2 decibels: Full Scale) in digital recordings, maybe
peaking at -1 at the most. Headroom in digital is a good thing, and you
often need it at mix time.
..and keep it around 0VU (which is -16 in
digital scale?)
This is a
really good question. Remember, a reading
on a VU (volume
units) analog
meter (with those cool little wavy needles) is showing you the overall
level -- and dbFS (decibels full scale) on a digital meter is showing
you peak level. VU meters have a "bonus" area of +1, +2, +3 (in
the red) but they were really designed with analog tape in mind.
When analog tape was around, there was actually 11 MORE dB of spec
headroom above +3 before the tape distorted. There is no such
invisible headroom on a dBFS peak meter - it's showing you
everything.
Why can analog have invisible headroom and digital can't? Because
analog tapes smoothly compresses (or rounds off) those tiny peaks that
you don't see on the meters. Analog tape sounds pleasant when it's
performing this smooth, invisible compression.
Digital, on the other hand, turns those tiny peaks into harsh square
waves when you exceed "0" and those clipping lights start flashing. Ok,
so you don't hear it at first. Those chopped off peaks cause subtle
irritation - so in most cases, we trust the meters and keep levels from
clipping when possible.
Meter
levels pertain to a certain amount of signal strength that
relates an amount of voltage to an amount of volume. The signal
strength and volume depends on what you put into it... so a test tone
will show a certain reading (there's no peak information in a sine wave
test tone) but music will show something else, depending on how much
energy is in the signal. Lows have more energy than highs --- but
a peak is a peak is a peak - regardless of the overall output
energy!
A -16 dBFS
sine wave test tone will in fact give you the standard (+4
line level) signal strength if the output of your D-A
converter (DAC) is calibrated
to give you 0VU (line level). But people have different settings on
different systems. I've seen "0VU" be anything from -10 to -18. The
important thing is to stay away from the digital clipping in any
digital recording system (DAW, Masterlink, DAT, etc.). Tip: Leave out
the master fader buss (but some systems require it). Your tracks - when
sending out to a mix - should be mixed so that the digital output
signal has no clipping. Then, set the gain for your speakers/amplifiers
to operate at the SPL (sound pressure level) you need.
Problem: Assuming we're still
talking about a DAW situation, the RMS (overall) level is low when you
see it on an analog VU meter. This low level corresponds to the low
level on your CDR copies (so long as you haven't put it through a
Finalizer or "mastering" pluggin to address this issue). When engineers
(in all good intention) try to compensate for that low level, they can
unknowingly get into trouble and lessen the quality of the mix.
One common
method I see is when the engineer puts a compressor on the
stereo buss, enabling him (or her) to bring up the level. The
compressor can even out some RMS surges that don't show up on digital
meters, so when used carefully, it can be a good thing. But from my
perspective, it's better to compress the individual tracks that are
causing those surges instead of pushing down the whole stereo mix when
that surge occurs. This is why RMS VU
meters are a good tool to
have (at least) for your stereo mixes. But how do we make
the two
kinds of meters match so that you get the benefit of each without that
Finalizer to approach a more "mastered" sound?
The NEMO
DMC-8 meter range switch is designed to help this exact
problem. You set your workstation to operate normally, and visually
calibrate the VU meters to match your DAW. Now you can watch the
digital peak meters and see RMS levels on the VU meters. This helps the
engineer make better mixing choices in case some vocals or other
non-peak sounds surge out (even though the peaks aren't going "over"). The
engineer can now adjust the compression on voices, bass and other
instruments more accurately by being able to see both kinds of meters
in a matched context (situation). This is an entirely
new idea
only found on this monitor module.
What average level do you recommend for
tracking?
If I had
VU meters on every track, and the tape was aligned to +5, I
would set the kic level to -2 VU, snare to -1V, hi hat to -6VU, toms to
-1VU, overheads to -3VU, bass to -1 or 0VU, vocals to 0VU or +1
occasionally, guitars to 0VU, keyboards to -1 or 0VU, high percussion
like tambourine to -10 or -8VU, conga or low percussion to -2VU,
strings to -2VU, brass to -2VU. Hi frequency peak material needs more
headroom.
On digital,
just stay -1 to -2dB below clipping.
I thought that I have to get some
audiophile cables that I can take all the advantage out from the DMC-8
Better
cables are a good way to improve the sound, but regular cables
won't damage the good qualities of the DMC-8. Sometimes we
have to take upgrades in steps - sometimes big steps, sometimes small.
The DMC-8 will still be a big advantage even with regular cables. With
every improvement you make in the chain, it will be more evident
(you'll know it more) because the DMC-8 is giving a better signal to be
revealed.
You wrote on one of your webpages that you
don´t like active speakers, because the electronics are in
movement, but Genelecs have these rubber "holders" for the electronics,
and while the subwoofer is connected all the lower frequensies are
coming out from the sub, so the speakers are not "shaking" too much.
I have my
power amp 6 feet away from my speakers, and when I use heavy brass weights
on top of the amp to stop vibration, it helps the sound! The power amp
inside the Genelec speaker, regardless of isolators, is vibrating a lot.
I have two kind of sticks (wooden) under my
speakers and I think it clarifies the sound, what do you think, could
it help or am I just imagining? (I didn't´t find those glass marbles anywhere)
You're
using the same idea, which is to disconnect (decouple) the
speaker from the stand. Trust your ears! Pet stores should have some
flat-style glass marbles... like Petco I guess. If you want easy
enhancements for your sound now, check out the high end power cords
that open up the top end, extend the bottom, and focus the sound of any
gear... Plus vibration
isolators and more!
American engineers are great people, always
so helpful. I have e-mailed to engineer called Bruce Miller too and he
mailed back in 2 hours! I was really pleased! I´ve wrote several
and several e-mails for Finnish engineers and studio staff and nobody
have replied, and I´ll bet they are not that busy that you are!
Many of us
know the good feeling of helping our fellow engineers. I
hope this helps.
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