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120W speakers and Sonos AMP

  • 29 March 2019
  • 5 replies
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Hi, I wonder if using 4 120W 8 ohm speakers in parallel in a Sonos AMP is safe? I know that each channel in the AMP is 125W and I'm afraid of damaging the speakers if I turn up the volume to high. Please anyone help me here? Thanks!
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Best answer by Stanley_4 29 March 2019, 20:03

The 5 watt difference wouldn't be a problem using a single pair of speakers, when using four the 125 is split so each speaker will only see a bit over 60 watts, completely safe.
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The 5 watt difference wouldn't be a problem using a single pair of speakers, when using four the 125 is split so each speaker will only see a bit over 60 watts, completely safe.
Thank you Stanley!
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If you connect a pair of 8 ohm speakers in parallel then the amp is driving 4 ohms nominal load. The amp can put out over 200W into 4 ohms (so >100W per speaker assuming the speakers are matched). You are probably safe but if you are worried there is a function to limit the volume. I use this since my kids use my amp and it definitely has enough power to blow my speakers.
Counter intuitive perhaps, but the bigger problem is with underpowered amps, not those that seem to be too powerful. In both cases, irresponsible use of the volume control can destroy speakers, but with underpowered amps that clip, this can happen before the sound levels become too loud, and is therefore easier to unwittingly accomplish.

In your case, the bigger concern would be how honest the 8 ohm spec is - some speakers with this spec can drop impedances at times to even below 4 ohms depending on the music being played, and if two speaker pairs do this, even the Sonos Amp may go into self protection mode and shut down.

See the link to make sure you are doing the right things on the wiring front:

https://support.sonos.com/s/article/265?language=en_US
"120W speaker" just means it can handle up to 120W of power, probably at peaks, not continuously. What matters more, really, is the impedance rating of the speaker, in Ohms. Two 8 Ohm nominal speakers wired in parallel present a 4 Ohm nominal load to the amplifier, which the Amp should be happy with.

If you really mean to wire four speakers in parallel, though, and each is nominally 8 Ohms impedance, that would present a nominal 2 Ohm load to the Amp, which I doubt it's rated to handle. Few amplifiers are.

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