Meyer Sound 600-HP - Manual (Page 16)

10
CHAPTER 3
NOTE: Most source equipment is safe for
driving loads no smaller than 10 times the
source’s output impedance. For example an equal-
izer with a 150 Ohms output impedance should be
able with drive a load of 1500 Ohms.
TIP: If abnormal noises such as hum and
popping are produced by the subwoofer,
disconnect the audio cable from the subwoofer. If
the noise stops, then most likely the problem is not
with the subwoofer. Check the audio cable, source,
and AC power for the source of the problem.
Meyer Sound LD-1A, LD-2, and LD-3 line drivers and
the Galileo 616 loudspeaker management system are
highly recommended when driving systems using multiple
loudspeakers. These line drivers, in addition to maintain-
ing signal integrity for long cable paths, offer independent
outputs and filters to help you integrate 600-HP subwoof-
ers into your system.
NOTE: For details on the 600-HP’s audio
input characteristics and amplification, see
Appendix B: Specifications.
600-HP INTERCONNECTIONS
The 600-HP utilizes two 4-ohm, 15-inch cone drivers,
specially designed for subwoofer applications. These
high-excursion, back-vented drivers are rated to handle
1200 AES watts. Each channel of the amplifier drives one
low-frequency driver.
CAUTION: All Meyer Sound loudspeakers
are shipped with the drivers in correct align-
ment. However, if a driver needs to be replaced,
make sure the replacement is reinstalled with the
correct polarity. Incorrect driver polarity impairs the
system performance and may damage the drivers.
The 600-HP is powered by the Meyer Sound HP-2/600
two-channel amplifier. The class AB/H amplifier utilizes
complementary MOSFET output stages capable of de-
livering 2250 watts total output power (4500 watts peak).
All specific functions for the 600-HP, such as crossover
points, frequency and phase response, and driver protec-
tion are determined by the control card installed inside the
amplifier.
CABLING
The 600-HP is available with two different cabling/con-
nection options. One is the Meyer Sound/VEAM cable
system, which combines AC power, audio signal, and
RMS network data into one heavy-duty cable with a single
matching connector per 600-HP cabinet.
The other (standard) system uses three separate cables
and connectors per cabinet for the AC line current, signal,
and RMS data. However, the three can be consolidated to
create a “multi-cable” by looming them together for quick
connection to each cabinet. This ensures no patching er-
rors and a minimum of discrete cables behind if the
600-HP cabinets are stacked in an array.
A ring fitting is provided on the rear of the 600-HP
loudspeaker to act as a strain relief for cabling. Using this
ring will minimize the chance of cables being damaged
during installation.
Figure 3.3. Tie cables off using ring (shown with rain hood installed).
600-HP LIMITING
The 600-HP uses Meyer Sound’s advanced TruPower ®
limiting. Conventional limiters assume a constant loud-
speaker impedance and therefore set the limiting thresh-
old by measuring voltage only. This method is inaccurate,
because the speaker’s impedance changes in response to
the frequency content of the source material and thermal
variations in the speaker’s voice coil and magnet. Conse-
quently, conventional limiters begin limiting prematurely,
which underutilizes system headroom and lessens the
speaker’s dynamic range.
In contrast, TruPower accounts for varying loudspeaker
impedance by measuring current, in addition to voltage,
to compute the actual power dissipation in the voice coil.
TruPower improves performance before and during limiting
by allowing each driver to produce maximum SPL across
its entire frequency range.
NOTE: TruPower limiting only reduces the
signal level to keep the voice coil below
180° C, hence peaks are unaffected.