The Difference Between and 8 Ohm Audio System and a 70.7V System

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An 8 Ohm audio system is a conventional speaker system that utilizes two wires (think positive and negative) going back to the amplifier.  This type of system is normally used in a hi-fi system or surround sound system where no more than one speaker is connected to each output of the amplifier.  To benefit from the hi-fi or surround sound, the listener needs to be in a specific spot, typically sitting at the end of a triangle between speakers and listeners.  Surround sound operates on the same principle, although the seating arrangements may differ slightly.

In a commercial environment, the listener will be moving around the floor, and the emphasis is on a uniform sound level wherever the listener is located in the room.  In most cases, more speakers than 2 are being used, all sharing the same single output from the amplifier.  In this case, a 70.7V system is preferable for a number of reasons.

  1. A 70.7V system only requires a loop from the amplifier to the first speaker, to the second speaker, third speaker, and so on.  There is no need to “home run” each speaker back to the amplifier, so installation is much easier.
  2. An 8 Ohm system relies on 8 Ohm speakers.  The 8 Ohm rating is a rating of the resistance the amplifier will see when it pumps out the audio.  If two 8 Ohm speakers are connected in parallel, the amplifier will see 4 Ohm.  If 4 speakers are connected in parallel, the amplifier will see 2 Ohm – a resistance most amplifiers are not built to handle.  To avoid this problem, it is possible to wire the speakers in series and parallel, but this is very complicated and time-consuming.
  3. A 70.7V amplifier is also built for commercial duty.  You will find that all our amplifiers have a 5-year warranty.  They are built to be on 24 hours a day, 365 days a week.  An 8 Ohm amplifier is, in most cases, built for home use and not expected to be on for more than a few hours per day.

70.7V speakers also allow for volume adjustments on individual speakers which may or may not be useful.  Please read our post on how to design a 70.7V system.