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

10 - SUBWOOFER OPTIONS

VTX A8 presets are designed for a 3:2 minimum cabinet ratio when used with the VTX B18, and a 3:1 ratio for when used with dual-18"
subwoofers line the VTX G28 or VTX S28 . The minimum recommended ratios provide sufficient headroom for both the subwoofers and
the full-range cabinets to reach MAX SPL (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.
VTX A8

10.1 SUB / LF PRESET OPTIONS

As previously mentioned, there are two LF presets available for the A8 system: one is the VTX A8 (full-range) preset, which extends the
frequency response of the system down to 50Hz; the other is the VTX A8 80 (80Hz) preset, which extends the frequency response of the
system down to 80Hz. The VTX A8 (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 subwoofers are used, the A8's LF region is overlapped with the subwoofers for
additional output in the shared range. The VTX A8 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 B18 80) is compatible for use with either
the VTX A8 or VTX A8 80 preset, simplifying preset selection. When multiple A8 arrays are used (i.e. main and side arrays), all VTX A8
arrays should be operated in the same LF mode for headroom consistency.
Example 1: A8 80 | SUB: 80
20
10
0
-10
-20
20 100
VTX B18
1000
Frequency (Hz)
VTX A8 | User Manual
VTX S18 / G28
Example 2: A8 FR | SUB: 60 or 80
20
10
0
-10
-20
20 100
25
SUB: 80Hz
SUB: 60Hz
1000
Frequency (Hz)