100V Line vs. 8 ohm speakers

Can you explain the difference (in non -technical terms) between 100V and 8 ohm speakers, and which we should choose. We require four speakers in our church.

Many older 100V speakers did not sound very good, and so lots of churches are changing them to modern speakers. However, new speakers, including the Control25 (8ohm) and Control25T (100V) speakers sound the same today. Therefore it is just the manner in which the signal is sent to the speaker which is different between the two systems. If you go for 8ohm speakers, you obviously connect them to the low impedance output from your amplifier and if 100V then connect to that output (note not all amplifiers have a 100V output).

The difference between the two systems comes in the wiring to the speakers. If you use low impedance speakers over long distances (greater than maybe ten metres) you need increasingly thicker copper in the speaker cable otherwise you get a lot of cable loss and distortion. So, for long distances 100V line is much better as you can pretty much use any old speaker cable.

Additionally, you mentioned that you wanted four speakers. With 100V line, you can literally connect all the + terminals together and all the - terminals together in any way the wiring happens to be. With 8 ohm speakers, you need to ensure that the impedance is above 4 ohms, which with four speakers involves wiring pairs in parallel and then connecting the pairs as a serial chain.

Most older churches are wired for 100V line systems as the speakers are both a long way from the amplifier and also the cable is not of thick copper. Therefore if you are updating your system it is highly likely that 100V speakers are suitable.

To say it again, with modern speakers, both 100V and low impedance speakers sound very similar.

Hope this helps,

Tim