If you’ve ever lost a commercial job to a “70V guy” – there’s probably a good reason. Price. Not only are 70V systems typically less expensive, but they are specifically designed to handle a number of loudspeakers over long wire runs. This is also why they are also a favorite of many dealers for backyard patio solutions. The way this is done is simple, 70V/100V (aka “constant “voltage”) systems send higher voltage at lower current. This eliminates the need for beefy amplifiers and heavy gauge homeruns of wire, plus it simplifies system design.
Major System Advantages - Cost Savings
- Multi-channel amplifiers are typically not required
- Smaller gauge wire – and less of it – is required
- Time Savings
- Daisy chained wire pulls and no need to perform complex system design.
- Customer benefits
- Microphone inputs and paging functions
- Simplicity of use (think wait staff…)
Designing a 70 Volt SystemAs stated, the time and effort to design and install a 70V system is less than with conventional amplification systems. But why is that exactly? Below are the basics for what you need to know when designing and installing your first 70V system.
- Determine the locations for the speakers and how many you will need for proper audio coverage.
- Select a 70V speaker with the appropriate “taps” (or volume level) for that application. <1W is typical for background listening while up to 60W may be used for wider coverage or louder music. A large lobby or outdoor area, for example. Note the tap setting (wattage) you intend to use for each speaker.
- To determine the amplification needed, just add up the total power of the taps you will be using on each speaker, then add 20% as a safety factor. This total must be lower than the rated output of the amplifier being used.
That is all you need for a basic design! Sure beats figuring out complicated impedances, right? When used in the right applications, 70V systems can provide tremendous benefits to both you and your customer!
