System schematics: the central brain of an audio-visual integration

Across the various kinds of audio-visual design documentation prepared for a typical integration project, most people in the field would agree that the system schematic is the central brain. It ties everything together by setting out the functionality, performance and application of a proposed system within a particular space.

From a design point of view, most of the supporting drawings are built off the schematic: floor plan and reflected ceiling plan arrangements, rack layouts and elevations all follow from it. For most standard room types, an experienced installer can set up an entire system from the schematic alone, without supplementary architectural layouts. The exception is a highly complex system involving multi-room linking or several floors. The schematic works this way because it carries every key aspect of a system’s technical requirements for deployment on site.

What a good schematic has to show

At the bare minimum, a sound system schematic should reflect the following:

• Equipment block models, with individual connector inputs and outputs
• Cabling detail and labels
• Descriptive information, such as device mounting details, existing or client-supplied devices, included kit accessories, and speaker tapping and audio configurations
• Equipment locations
• Power and data allocation requirements

Every port, whether it is used or not

In our view, the defining quality of a schematic lies in the accuracy and clarity of its equipment block framework. Every connection port and connector type on a device should be shown, whether or not the port is in use.

From a drafting perspective this takes time, particularly on large switcher and processor blocks. There are two reasons it saves time and cost later.

First, it gives the installer an accurate overview of every available port, which matters when site conditions force a change to cabling and port allocations to make the system work. Second, it makes a planned upgrade far easier to assess, because the possibilities within the existing system are already on the page.

The as-built schematic then becomes the primary reference for the installed state of the system. Between design, planning, installation, commissioning and later maintenance, the schematic is the drawing everyone returns to. Its preparation deserves careful, patient thought, and should never be underestimated.