Typical 70V System Designs / Installation Notes
There are many applications that 70V systems can be used for. In an office building with multiple offices, volume controls (VC’s) can be installed in every office to accommodate levels as needed. In a theme park you could install horn speakers all the way up roller coaster lifts, and queue lines. A very common use is for “Paging” and “Background” music. 70V speaker lines can be run very long distances without the “expense” and worry of “line loss.” The downside of using 70V systems is that the lower frequencies will suffer more than a regular 8-ohm system. Here is my very first experience with installing and setting up a 70V speaker system.
70 Volt System Wiring Notes
Of course, as with any speaker system there is a “right way” and a “wrong way” to wire up the speakers. When working with 8-ohm systems if you reverse the polarity on one of the speakers there will likely just be a “phase” problem. With 70V systems if you get the polarity wrong it could (but not always) damage equipment. It’s very simple – positive to positive and negative to negative. No matter how careful an installer is – there are still mistakes made out in the field. The correct and incorrect ways to connect 70V speakers are shown below.
