Recording - June 2019 - 24

Two old-school
practices to benefit
modern recordings
By Paul J. Stamler

Tone

When we discuss tone, we're not
talking about what you adjust with the
tone control(s) on your electric guitar, and
not that Magical Thing that distinguishes
Eric Clapton from every other guitarist
(sigh). No, I'm talking about a 30- or
60-second recording of sine waves,
usually mid-frequency (400Hz or
1000Hz-but keep reading). Tone used
to be a ubiquitous tool in professional
recording studios, and I'm going to
argue that it could be useful again.
This article was inspired by Eric
Ferguson's excellent "Loudness: What
You Need to Know" (Recording, Oct.
2018). If you can, go find that article; it's
a good introduction to a gnarly subject.

Tone then

How was tone used in studios in what
John Hartford called The Goodle Days? It
was primarily a matter of communication
between engineers. And to understand
that, you need to know about the concept
of nominal level.
Nominal level, to view it simplistically,
was how loud a recorded signal was, and
you usually measured it with a VU meter
(see the other half of this article). They still
exist, and they're still useful. Hardware
VU meters are mechanical devices, with
defined ballistics-a standard specified
how quickly the needle would jump up
to the nominal level point, defined as 0vu
(yes, the standard specifies lower-case).
24 RECORDING June 2019

What is useful is that, if two things
match on a VU meter, their listening
levels will probably also match
reasonably well. VU meters came from
the world of radio broadcasting, and
were developed because broadcasters
needed to ensure that program elements
like musical interludes, announcements,
and (most importantly) commercials
were all at matching levels; if the
operator kept all of these at 0vu, the
listeners would hear a seamless flow.
When tape recording became
ubiquitous in recording studios in
the late 1940s, everything was
standardized. The tapes and recorders
of the time worked well with a nominal
0vu of 185 nWb/m-the abbreviation
stands for "nanowebers per meter", if
you're curious. You don't really need to
know that; just know that the nominal
level on tape-specified by Ampex,
the first big maker of tape recorders-
was 185 of them.
That produced a good recording on
full-track 1/4" tape, with reasonable
signal-to-noise and headroom. As
tracks got narrower with the advent
of stereo and multitrack recording, the
tape's signal-to-noise ratio suffered,
and engineers wanted to record at
higher levels to be clear of the noise.
In the 1960s nominal level was
redefined (by a lot of engineers and
manufacturers) as 250nWb/m; later,
in the 1970s, tapes which would
accept considerably higher levels
were developed, and a lot of people
calibrated their machines to 320 or
510nWb/m or even higher. Nothing
matched any more.
This became a big deal when
engineers cut vinyl records from the
tapes. If you were a cutting engineer,
with a stack of tapes that you needed

to turn into records, the effective
anarchy of nominal levels was a
real problem; those tapes would,
without the engineer's intervention,
generate records of drastically different
loudnesses, because their nominal
levels were all over the place. And there
wasn't always time to fast-forward into
the recording and see what the actual
level was, because time was money.
As a matter of mutual self-defense,
it became standard practice in studios
to place 30 seconds or so of midfrequency tone at whatever level your
studio used for 0vu at the head of each
reel of master tape, so the mastering
engineer could set the nominal level
properly. Really nice engineers
also put some 0vu high-frequency
tone-say, 10kHz-so the mastering
engineer could verify that the deck
being used for playback matched the
recording studio's EQ and azimuth...
but that's story for another day.

Waves Dorrough
Stereo 380d Meter
Recording - June 2019

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