Crown Audio VRack4X3500HD - Manual (Page 12)

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 22 page 23 Operation Manual
To enable VDrive, open the VRack device panel. This selection is located in two places. You only need to select it in one place.
1. Under the ‘Presets’ Tab, it is located under the Digital Input Status section
VDrive must be selected if using
the VRack4x3500HD input panel
To enable VDrive, open the VRack device panel. This selection is located in two places. You only need to select it in one place.
2. Under the ‘Input’ Tab, it is located in the upper left section of this tab.
VDrive must be selected if using
the VRack4x3500HD input panel
Output Wiring Modes