Crown Audio VRack12000HD - Manual (Page 28)

JBL and Crown have established this set of recommended circuiting configurations for all VerTec/iTechHD systems worldwide.
Please follow these good/better/best guidelines in order to ensure optimum system performance.
High Performance
A High Performance (HP) system has the following characteristics:
• 1:1 Ratio of Tops to Subs
• NO sub or LF section loads below 4ohms
• 2 cabinets per circuit for optimal array shading and tapering resolution
• Best possible power match to iTechHD amplifiers, with most systemwide headroom for loud concerts and highly dynamic
content.
Nominal
A Nominal (Nom) system has the following characteristics:
• 3:2 Ratio of Tops to Subs
• Some driver loads at 2.7ohms
• 3 cabinets per circuit for good match between power handling and array shading and tapering resolution
• Appropriate power match for iTechHD amplifiers, good balance between systemwide headroom and increased array
coverage
Economy Power
An Economy Power (Econ) system has the following characteristics:
• 2:1 Ratio of Tops to Subs, or no subs
• Some driver loads at 2ohms
• Using 3-Way+3-Way mode which powers lows at 2ohms on a circuit of 2 x VT4889 or VT4888
• Economy mode is appropriate for speech or music reinforcement with limited SPL requirements.
Operation Manual page 28
Output Wiring Modes