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Dynaudio LYD Series
Personal Reference Monitor
Listening tests / Final tweaks
Listening
tests
Once you have your speakers properly positioned, its time to start
listening to them. Subjective listening tests can be made with reference
material that you are familiar with; a favorite album, movie or other
recording. Objective tests can be made simply with a smartphone
app or more sophisticated acoustic measurement system.
Reference material
Play some recorded material that you are familiar
with through the speakers to see if the sound
is what you expect. Adjust the tilt filters both
directions to hear the different tonalities that
are possible. It is also suggested that you listen
to material you know actually sounds bad or
has defects in the recordings. A truly neutral
loudspeaker will reveal these defects clearly.
The whole point to a good loudspeaker is to
get accurate representation of the sound, good
or bad, so that mix decisions can effectively be
made. Adjust the tilt filter to the setting you are
most comfortable with.
Pink noise
For an objective test of the speaker’s response,
you will need a metering system. This consists
of a device that can measure the spectral output
of the loudspeaker in real time and a source of
pink noise that can be played back through the
loudspeakers.
• RTA Spectral Analyzer
• Pink Noise Source
Dynaudio has created an iOS app with these
tools built in so you can quickly test and calibrate
your LYD speakers using your iPhone, iPad or
iPod touch. In the Apple App Store, search for
“Dynaudio Meter” to locate and download this
free app.
You can connect the device directly to the
speakers using a conventional headphone to RCA
adapter. Play the pink noise from the Dynaudio
Meter and adjust the level for a reasonable
playback volume. If you wish to play pink noise
from your computer workstation, a WAV file
containing pink noise is available at:
www.dynaudio.com/pinknoise
Play the pink noise through one speaker at a time
at a reasonable level (~80-85dBA) and place the
iPhone or iPad at the listening position. Change
the Sound Balance filter to see how the response
changes the response curve in the RTA. Pink
noise is a balanced level of noise across the entire
spectrum. In the RTA display, the reading should
be as level and even as possible.
If you notice excessive levels in the low frequencies,
try setting the Sound Balance filter to Bright (B)
and check the results. If the spectrum analyzer
shows a greater degree of high frequencies, set
the tilt filter to dark (D) and check the results.
Once you have the tilt filter set for the flattest
response curve in the RTA, return to your
reference material to see how it sounds. Through
this process of objective tests with the RTA and
subjective listening tests with you ears, you
will arrive at the best setting for your Dynaudio
loudspeakers.
Beyond the settings for the loudspeakers, additional tweaks may be
desired to improve the response of the system and room environment.
You may discover that a reflective surface is causing a high frequency
anomaly or perhaps room modes are disturbing the bass response
in the room.
First reflection treatment
Sound reflecting off of hard surfaces that are
close to the listening position can cause problems
in the high frequency response and imaging of
the loudspeakers. These first reflections can be
relatively easy to fix in many cases. Figure 7 shows
some common causes of first reflections in a
typical control room.
First reflections can be located easily by using a
mirror placed on various surfaces in the studio
to check if you can see either loudspeaker in
Final
tweaks
Figure 7: Reflection diagram
the mirror when sitting in the listening position.
If you can see either loudspeaker in the mirror, it
follows that upper frequencies will bounce off that
surface directly back to the listening position and
potentially cause response problems.
Placing absorptive material on these surfaces
will reduce the effect of first reflections and
improve the sound of the system. The thicker
the acoustic material is, the more effective it will
be. Also, creating an air space behind the material
will improve its effectiveness. Place as much
absorption that is practical at the first reflection
points to improve the response of the system.
Bass trapping
If you notice any peaks or dips in the low frequency
response curve of the RTA (20-250 Hz), they may
be caused by room modes. Room modes occur
at specific low frequencies that have wavelengths
that are equal to or multiples of the dimensions
of the listening room.
For example, if the listening room is 4 meters
long, there may be a room mode at 43 Hz since
its wavelength is about 8 meters. What this means
is that for this frequency, the room response will
change dramatically depending on the position
of the listener and the loudspeaker. You may hear
a more of this frequency or less of it depending
on the listening position in the room. Modes
can be formed from all dimensions of the room;
length, width, and height. The solution is to place
sound absorption designed for low frequencies
in the most effective places to reduce the effect
of room modes.
Many manufacturers make sound absorptive
devices called bass traps that are designed to
be placed in or near corners and will reduce the
amount of reflected low frequency energy in the
room. By dampening the resonance of the modes,
the low frequency response of the room may be
smoothed out.
When placing bass traps, always check the
resulting frequency response curve with pink
noise and an RTA to ensure that the loudspeaker
response is improving. Then listen to your favorite
reference material to see how this affects it.
