Subwoofer Options; Sub / Lf Preset Options - JBL VTX A12 User Manual

9 - SUBWOOFER OPTIONS

VTX A12 presets are designed for a 3:2 minimum cabinet ratio (A12 : VTX S28 or G28 subwoofers). The 3:2 ratio
provides sufficient headroom for both the subwoofers and the VTX A12s to reach MAX SPL (the limiters) at the same
time, while maintaining a minimum of 10dB SUB to TOP low-frequency contour. Other ratios can be used depending on
the desired tonal balance target, MAX SPL and application.

9.1 SUB / LF PRESET OPTIONS

As previously mentioned, there are two LF presets available for the A12 system: one is the VTX A12 (full range) preset,
which extends the frequency response of the system down to 45Hz; the other is the VTX A12 80 (80Hz) preset, which
extends the frequency response of the system down to 80Hz. The VTX A12 (full range) preset is used when the system
is operated without subwoofers or when the application calls for extended LF response from the main arrays. If subwoof-
ers are used, the A12's LF region is overlapped with the subwoofers for additional output in the shared range. The VTX
A12 80 (80Hz) preset is used only when subwoofers are available and when the highest A-weighted sound pressure
level (SPL) is required. The same subwoofer preset option (i.e. VTX S28 80) is compatible for use with either the VTX
A12 or VTX A12 80 preset, simplifying preset selection. When multiple A12 arrays are used (i.e. main and side arrays),
all VTX A12 arrays should be operated in the same LF mode for headroom consistency.
Example 1: A12 80 | SUB: 80
20
10
0
-10
-20
20 100
VTX
A12
1000
Frequency (Hz)
VTX A12 | User Manual
VTX VTX
S28 G28
Example 2: A12 FR | SUB: 60 or 80
20
10
0
-10
-20
20 100
19
SUB: 80Hz
SUB: 60Hz
1000
Frequency (Hz)