The Knowledge and the Tools You
Need to Fine-Tune a System
Anthony Grimani (email@example.com) is
president of Performance Media Industries,
with offices in Novato and San Anselmo,
The process of debugging, configuring,
and tuning the audio and video is all-tooften
or simply ignored in our industry. The
trouble is, when you skip these steps,
systems can grossly under-perform to the
point of embarrassment.
The simple fact is that you have to
take the time to calibrate. You have to
understand how to do it. You have to have
the tools. Either that, or you have to go find
someone who does. Otherwise, in a certain
sense, you are stealing from your customer.
And that’s too bad, because we’re talking
about a very high value-added service that
produces tangible, visible, and
Step One: Debugging the
Initially you must test and document the performance of your
system’s audio and video equipment, and its connections and signal
flow, using tools like multi-meters, oscilloscopes, and spectrum
analyzers. It is impossible to do this without the proper test gear and
knowledge. Simply running sound or picture into the system and
verifying that something comes out the other end is inadequate. If
you can read mV or check the electrical frequency response of a
cable by touching your fingers to it, then you don’t need test gear
(also, send me your resume.) For everyone else, test gear is a must.
Step Two: Configuration
Configuration tells every piece of equipment what it is and what to input/
output. Modern AV controllers and receivers can have approximately 100 individual settings per device hidden away in countless menus
and submenus. We’re talking about settings that directly affect audio
performance, video performance, operation/control, and networking.
Never assume that the default settings will work. They might, but there
could be one tiny thing in an obscure piece of equipment that completely
destroys the audio-video performance of the entire system.
Step Three: Tuning
This is where many people think calibration begins. Here, we’re talking
about things like setting distances, SPL, and EQ for the speakers, and
picture controls and color temperature for the video display. Once again,
you cannot do this without test gear.
To give you some idea of the substantial amount of work involved, you
should budget three days of audio and one to two days of video for the whole
process. Don’t pull the classic, “We’ll-figure-out-how-to-charge-for-this-atthe-
end” line. This process should be taken much more seriously than that.
As an aside, please install products
that can be calibrated. For instance,
sell video displays that enable color
temperature and primary color
adjustments and audio products that
allow channel levels and speaker
distances to be adjusted in half dB and
half-foot (or less) resolution.
Don’t Depend on Free or Automated
Manufacturer-sponsored (free) calibration services only look at one
specific part of the system–their part. True calibration looks at the whole
system from input to ear/eye.
Don’t make it automated, either. High-tech analyzers and computer
algorithms can’t solve every problem; even the most sophisticated systems
can’t get it exactly right. They cannot, for example,
analyze the dramatic effect that tiny changes in
delay make to the positioning of a front-to-surround
phantom image. This requires a human head with
ears tweaking from the chair.
Consider this as a parting thought: A really
good calibrator can often smooth over design and/
or installation flaws that would otherwise require
thousands of dollars to fix. What kind of value do
you put on that?
Chase Walton contributed to this column.
>To Hire or Sub Out the Work?
A bona fide calibration specialist can make upwards of $150,000 a year, and most ES Cs
can’t afford that unless they are installing at least 50 systems a year. Neither would
you use the test gear often enough to remember how it works or justify the cost. If you
don’t have a huge business, then hire a professionally trained, third-party calibrator. As
an added bonus, you get fresh eyes to pick up on mistakes and goofs. Factor the cost
(up to $4,000-6,000) into the budget, mark it up, and pass it along