Recording - July 2015 - 8

Note to faithful writers: When sending your letters by email,
please remember to include your name and where you hail from.
Can we pre-correct for Equal Loudness Contours?
Hi Mike: Thanks for a very easy to understand article on
listening levels and the Fletcher-Munson curves a.k.a. Equal
Loudness Contours. After reading your article I got to thinking... if our hearing changes what we perceive with
changes in volume, why not put a master EQ after the
mixer that has different curves for different volume levels?
My thinking is most digital EQs, whether outboard
hardware or software plug-ins, have multiple preset settings. Each Phon curve could be saved and used as
needed. For example, If I'm playing back 80 Phons use
that preset, if I'm at 30 Phons use that preset, so no matter what level I choose, I've compensated for how we
perceive frequencies at different volume levels.
Do you know if there is a way to set up an EQ to mirror the Equal Loudness Contours? Thanks for an interesting article and a great magazine. Peace,
RL Alexander
Pleasantville, NJ

Hello RL, nice to hear from you again! I'm glad
you're enjoying the magazine as much as ever.
I guess the easiest answer to your question would be
to say, "In theory, there is no difference between theory and practice, but that doesn't hold up in practice."
While it should be possible to create an EQ curve that
mirrors the Equal Loudness Contours and lets you turn
your levels up or down at will, in practice there are
other factors that might skew your results.
For example, if your room has a resonance at a particular frequency, turning the level up will excite that frequency more, and cause deviations in that frequency
range. Note that this would happen anyway! But with
that "anti-ELC" EQ in place, you might be fooled into
believing that it doesn't, or not listen for it as carefully.
The only way to compensate for this would be to calibrate your room at different listening levels with a frequency sweep and program an inverse of each curve,
but then the EQ would be no good if you listened on
headphones; you'd have to do a separate set for those,
and headphone frequency response is highly variable
from person to person.
Note that the Loudness button on old stereo systems was
designed to do a compensation of this type, in a very
brute-force way, by boosting low end when you listened
at lower levels. It was very unscientific and would sound
different on different types of music at different levels, but
it was an easy way to quickly give a listener a more pleasurable experience. When you start talking about a scientifically reliable way to do this for all listening levels...
especially when you talk about inserting EQ into the audio
chain between your mix and your monitors!... experienced engineers are going to get very nervous.

Pro audio has a long history of audio processes that seemed like a
great idea at the time and haven't stood up very well in the long run.
While it's theoretically possible and the available hardware and software is getting more capable every year, doing something like this
won't win many fans until there's a real preponderance of evidence that
it can be done reliably. "First, do no harm" was good advice for physicians 2000 years ago and it works well for engineers today. Many
thanks for reading!-MM

Clipping un-conundrummed
Hello! I would like to thank Paul Stamler, Giles Reaves, Mike Rivers,
and Paul Vnuk Jr. for their article that appeared in the March 2015 issue
of Recording, "Crosstalk: The Clipping Conundrum." I am the guy who
"inspired" the article.
I actually wrote my original email question on clipping to Recording
back in March 2012, when I was a beginner with Pro Tools and home
recording, and didn't completely understand what I was doing. I think
that might have been obvious by some of the things I conveyed in my
note, as Paul, Giles, Mike, and Paul pointed out!
Over the last 12 months, I have come a long way in improving my
understanding of Pro Tools and the mixing and mastering process...
thanks, in a big way, to the many articles that I have read in Recording
and the subsequent research that I did after reading those articles. You
guys have been a tremendous help. I am a subscriber for life.
The nice thing is, had I read this Crosstalk article three years ago, I probably wouldn't have completely understood it, but now it is crystal clear. I completely understand your points, and they are 100% accurate. Your guesses
on what I was doing were correct, and your solutions are spot on. I have
been able to eliminate my "clipping" problems and, in recent months, have
been able to make cleaner, more professional sounding recordings.
So... if there are readers out there who are novices like I was, and are
having trouble with clipping and audio processing, I would encourage
them to read that Crosstalk article very carefully. The solutions are there;
if you take the time to carefully read the article and implement the suggestions, you will eliminate the clipping problem.
Thanks again, guys. You told me in 2012 that you would get back to
me... boy! You sure did! I appreciate the article and love Recording.
Steve Bonaccorsi
via email

Our pleasure, Steve. It's good for our beginning readers to see that
no matter how confusing a topic might be at first, with persistence and
patience, anyone can learn to improve their recordings. Thanks for reading, and thanks for your letter.-MM
Correction
Whoops. When we published "The Tools And Tricks Of Drum Replacement"
by Pat Bautz, we got one critical piece of information wrong: Pat's website! The
proper sites to reach Pat for professional drum tracks for your home recordings
or other engineering services are realdrumstudio.com and mixyoursongs.com.
Sorry, Pat.-MM

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8

RECORDING July 2015

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Table of Contents for the Digital Edition of Recording - July 2015