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CHAPTER 5
USING 700-HP SUBWOOFERS WITH OTHER
MEYER SOUND LOUDSPEAKERS
It’s often necessary to augment mid-high or full-range sys-
tems with subwoofers when higher SPL is needed, or the
program content requires additional low-frequency energy
(e.g., the reinforcement of popular music).
The 700-HP subwoofer can achieve frequencies down in
the 28 Hz range, extending the system response appre-
ciably and increasing the acoustic power of the system in
the lowest frequencies. In addition, the use of high-pass
and/or low-pass filters to drive a system with subwoofers
can improve the interaction between the subwoofers and
the system in the crossover area as well as increase the
system’s headroom.
The ideal ratio of 700-HP subwoofers with respect to other
loudspeakers in the system depends on:
■
The loudspeaker type being used in conjunction with
the 700-HP (MILO, MSL-4, M2D, CQ-1, etc.)
■
The configuration of the system, whether flown or
ground stacked
■
The frequency content of the signal being reproduced
by the system, e.g., classical music, rock or speech
When considering the ratio of loudspeakers to subwoof-
ers in a system, it’s important to consider not only the
frequency response for the system, but also the required
headroom.
Common applications for the 700-HP involve using the
subwoofer with M Series and Concert Series loudspeak-
ers. In most circumstances, two loudspeakers for each
subwoofer yields good results in frequency response and
headroom. In demanding low-frequency applications, us-
ing higher ratios (for example, three loudspeakers for one
subwoofer) can have negative consequences — decreasing
the headroom at the low end of the spectrum and exposing
the 700-HP drivers to excessive power levels.
CAUTION:
The 700-HP’s limit LEDs indicate
when the safe power level is exceeded. If
the subwoofers used in the system begin to limit
before reaching the required SPL at low frequencies,
consider adding more subwoofers to satisfy the SPL
requirements without exposing the drivers to exces-
sive heat and/or excursion.
700-HP USED WITH CONCERT AND
ULTRASERIES
All Meyer Sound products have been optimized with inter-
nal crossover networks. When Meyer Sound loudspeak-
ers are used in close proximity and are coplanar, these
networks provide maximum power addition through their
respective overlapping frequency ranges.
Several basic connection options are available when using
the 700-HP subwoofer with other Meyer Sound Concert
or UltraSeries loudspeakers, as discussed in the following
sections.
Daisy-Chained
If 700-HP subwoofers and other Meyer Sound loudspeak-
ers are daisy-chained using the loop feature on the user
panel, the result is a smooth frequency response through
the “overlap range.” When the 700-HP and the other Meyer
Sound loudspeakers are coplanar, this usually occurs at a
ratio of two loudspeakers to each 700-HP. This is the con-
figuration commonly used in small systems.
NOTE:
Full-range signals may be applied to
Meyer Sound’s self-powered loudspeakers
and subwoofers because they have built-in active
crossovers.
The 700-HP subwoofers should be placed as close as pos-
sible to the other loudspeakers so that the relative distanc-
es between them are the same at all listening positions.
NOTE:
There is no polarity switch on the
700-HP and it is wired pin 2 “hot” (positive
acoustic pressure when a positive pulse is applied
to pin 2).
NOTE:
When 700-HP subwoofers are used
with Concert Series or UltraSeries loud-
speakers in their full-range configuration (e.g.,
looped audio or the same audio feed), their polari-
ties should be kept the same (set the switch on
the rear of the loudspeaker to Pin 2+) if they are
coplanar or near each other. If they are separated by
a greater distance — or delay must be used be-
tween them — a measurement system such as the
SIM audio analyzer should be used to determine the
correct delay and polarity.
CHAPTER 5: SYSTEM INTEGRATION
