Meyer Sound UPJunior UltraCompact VariO, Operating Instructions Manual

Page: 17 / 44

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CHAPTER 4: ADDING SUBWOOFERS TO A UPJUNIOR SYSTEM
A UPJunior loudspeaker system can be deployed with
Meyer Sound self-powered subwoofers (see Table 1). Sub-
woofers achieve very low frequency responses and extend
the system response appreciably, increasing the overall
acoustic power of the system in the lowest frequencies.
The ideal ratio of UPJuniors to subwoofers depends on the
following variables:
■
Subwoofer model
■
System configuration
■
Frequency content of source material
■
Headroom required for low frequencies
For most applications, the ratios in Table 1 should yield
good results.
Full-range signals can be connected directly to Meyer
Sound self-powered loudspeakers because the loudspeak-
ers have built-in active crossovers. Subwoofers can be
added to a UPJunior loudspeaker system by simply daisy-
chaining them to the UPJuniors. In more complex systems,
subwoofers can be added by using line drivers or digital sig-
nal processor to send multiple outputs to each sub-system.
In addition, you can use low-cut filters to flatten the overall
frequency response of the system while increasing the
UPJunior headroom in the lower frequencies.
NOTE: If the subwoofer’s Limit LEDs begin to
light before reaching the required SPL, con-
sider adding more subwoofers to meet the SPL
requirements without exposing the drivers to exces-
sive heat and excursion.
TIP: MAPP Online Pro™ can be used to accu-
rately predict the appropriate loudspeaker
deployment and subwoofer integration for a loud-
speaker systems, complete with coverage data, sys-
tem delay and equalization settings, rigging
information, and detailed design illustrations. For
more information, see “MAPP Online Pro” on
page 33.
ADDING SUBWOOFERS BY DAISY-CHAINING
When UPJunior loudspeakers and subwoofers are daisy-
chained using the Loop connector, the result is a fairly flat
frequency response. However, the response will show a rise
in the 60–200 Hz range where the loudspeakers’ response
overlaps at certain ratios (see Table 1).
To add a subwoofer by daisy-chaining:
1. Daisy-chain the suggested number of UPJuniors for your
subwoofer (see Table 1). Connect the source signal to
the Input of the first UPJunior, then connect the Loop
output of the first UPJunior to the Input of the second
UPJunior (and so forth).
2. Connect the Loop output of the last UPJunior in the
chain to the subwoofer Input.
3. Configure the polarities for the loudspeakers:
■ If the UPJuniors and subwoofer are coplanar, or they are
very close together (four feet or less), set their polarities
to the same value. If any of the loudspeakers have a
Polarity switch, set each switch to the up (+) position.
■ If the UPJuniors and subwoofer are more than four feet
apart, or if a delay is required between them, use a mea-
surement system like Meyer Sound’s SIM
®
3 to deter-
mine appropriate delay and polarity settings.
CAUTION: Make sure the source signal is suffi-
cient to drive the total load impedance of the
daisy-chained loudspeakers (see “Loop Connector”
on page 13).
Table 1: Recommended Meyer Sound Subwoofers
Sub-
woofer
Frequency
Response
Recommended Ratio
(Number of UPJuniors per Subwoofer)
650-P 28–100 Hz
±4 dB
2 x 1 for bass-heavy applications;
4 x 1 for flat frequency response (6 db of
attenuation for subwoofer)
600-HP 39–130 Hz
±4 dB
2 x 1 for bass-heavy applications;
4 x 1 for flat frequency response (6 db of
attenuation for subwoofer)
700-HP 30–125 Hz
±4 dB
4 x 1 for bass-heavy applications
USW-1P 35–180 Hz
±4 dB
1 x 1 for bass-heavy applications;
2 x 1 for flat frequency response
UMS-1P 29–135 Hz
±4 dB
1 x 1 for flat frequency response;
Not recommended for bass-heavy appli-
cations
!