Table of Contents
Advertisement
source material changes, and as thermal values for the
loudspeaker's voice coil and magnet vary. Consequently,
conventional limiters often begin limiting prematurely, which
reduces system headroom and dynamic range.
In contrast, TruPower limiting anticipates varying
loudspeaker impedances by measuring both current and
voltage to compute the actual power dissipation in the voice
coil. This approach improves performance, both before and
during limiting, by allowing the driver to produce the
maximum SPL across its entire frequency range, while also
retaining signal peaks. TruPower limiting also eliminates
power compression at high levels over lengthy periods, which
helps regulate voice coil temperatures, thereby extending the
life of the driver.
HF and LF Limit LEDs
The low- and high-frequency drivers for LYON are powered
by separate amplifier channels, each with their own limiter.
Limiting activity is indicated with two Limit LEDs on the user
panel (Figure 13). The HF Limit LED indicates limiting for the
high-frequency channel and the LF Limit LED indicates
limiting for the low-frequency channel.
Figure 13: LYON Limit LEDs
When engaged, the limiters not only protect the drivers but
also prevent signal peaks from causing excessive distortion in
the amplifier channels, thereby preserving headroom and
maintaining smooth frequency response at high levels. When
levels return to normal, below the limiter thresholds, limiting
ceases.
LYON performs within its acoustical specifications at normal
temperatures when the Limit LEDs are unlit, or when the LEDs
are lit for 2 seconds or less and then turn off for at least
1 second. If the LEDs remain lit for longer than 3 seconds, the
loudspeaker enters hard limiting where:
• Increases to the input level have no effect
• Distortion increases due to clipping
• Drivers are subjected to excessive heat and excursion,
thereby compromising their lifespan
CAUTION:
The Limit LEDs indicate when a
safe, optimum level is exceeded. If a LYON
loudspeaker system begins to limit before reaching
the desired SPL, consider adding more loudspeakers
to the system.
AMPLIFIER COOLING SYSTEM
LYON employs forced-air cooling with four ultra high-speed
fans (two primary, and two reserve) to prevent the amplifier
from overheating (see Table 3 for details). The fans draw air in
through ducts on the rear of the cabinet, over the heat sinks,
and out the rear of the cabinet. Because dust does not
accumulate in the amplifier and power circuitry, their lifespans
are increased significantly.
CAUTION:
To keep LYON from overheating,
allow at least 6 inches behind the cabinet for
proper ventilation.
Table 3: LYON Fans
Primary Fans
Type
Ultrahigh-speed
Number
2
Location
1 for each heat sink (2)
Fan speeds
<34 °C
and heat
34–50 °C
sink temp.
50–84 °C
>95 °C
<86 °C
CAUTION:
If a LYON loudspeaker system
consistently overheats before reaching the
desired SPL, consider adding more loudspeakers to
the system.
TIP:
When LYON is connected to an RMS net-
work, the Compass RMS software provides
additional feedback on the loudspeaker's hardware
status and operating temperature. For more informa-
tion, see Chapter 5, "RMS Remote Monitoring Sys-
tem."
CHAPTER 3: AMPLIFICATION AND AUDIO
Reserve Fans
Ultrahigh-speed
2
1 for each heat sink (2)
Half speed
<52 °C
Ramps up
>52 °C
Full speed
Full speed
Audio
>95 °C
muted, fans
muted, fans
continue at
continue at
full speed
Audio
<86 °C
unmuted,
fans
continue at
continue at
full speed
Off
Audio
full speed
Audio
unmuted,
fans
full speed
17
Advertisement
Table of Contents
