Designed for streaming music and powering your choice of passive speakers, at Smart Home Sounds we often see the Sonos Amp used to drive in-wall speakers and ceiling speakers in architectural installations.

While the Sonos Amp normally connects to a pair of speakers for a stereo performance, sometimes restrictions in room size or shape or even the speaker cables have been run incorrectly can mean that only one mono ceiling speaker can be installed.

And while you can always use a single-stereo ceiling speaker to obtain dedicated left and right audio channels from one physical unit, using two single-stereo units sees the Amp’s speaker handling capacity maxed out & requires 2 x 2 core speaker cables run to each location.

So, if you have mono speakers installed in multiple-rooms, but worry about hearing either the left or right channel only, the good news is that the intuitive Sonos Amp has a trick up its sleeve. And it’s called Dual Mono Mode. 



What is Dual Mono Mode?

Dual mono mode enables a Sonos Amp to feed both the left and right audio channels of your music into one mono speaker. This option proves useful when a dedicated stereo pair of speakers cannot be used, and a single mono speaker is the only viable option. 

How Does Dual Mono Mode Work?

Most music is presented to listeners as a stereo mix, with left and right channels forming a stereo field. So if there is a cymbal crash panned to the left channel of the music, this is then emitted from the left-hand speaker. Whereas a handclap may be panned to the right-hand speaker, for example. 



When only one mono speaker is available to reproduce your music, dual-mono mode ensures that no element of the stereo source is missing. Configuring either your Sonos Amp or Connect: Amp for dual mono sees incoming stereo music converted into a mono mix. 

And instead of the Amp’s speaker ports being assigned to the dedicated left and right speakers, each outlet gives a combined mix of both channels together. This means that any mono speakers connected to either of the Sonos Amp’s speaker terminals now reproduce both left and right audio channels simultaneously.  

When Should I Use Dual Mono Mode?

Although most applications permit the use of a dedicated pair of stereo speakers, there is a surprising number of scenarios where dual-mono mode proves useful.  If the following questions sound like something you’ve been asking yourself recently, perhaps dual-mono mode could be the solution for you and your Sonos Amp: 

“What if my room is too small for two speakers?”

If you have either one or two rooms that can only permit one speaker in each, a single-stereo speaker is worth considering to obtain a true stereo performance. But if you are using 1x Sonos Amp to drive single speakers in two rooms or more, the dual-mono mode offers a suitable solution for reproducing audio from both stereo channels.



“Will dual-mono mode help if my speakers are placed far apart from each other?”

In most scenarios, we normally suggest that a stereo pair of speakers should ideally be placed at a minimum of two metres apart from each other, in order for preserving the stereo field. Yet, in extremely large spaces, it may be difficult to hear the stereo effect. In this instance, the dual-mono mode will ensure both left and right audio channels are mixed for the same speaker to reproduce.

This may prove useful if you have a large open plan space with multiple mono speakers, all powered from the same Sonos Amp.


“My Sonos Amp powers a series of outdoor speakers. Is stereo sound really necessary?”

If you are using multiple speakers outside your home, and they are placed particularly far apart, sound quality can be affected by the noise of the great outdoors. As the details in a typical stereo field can be lost through external environmental factors, dual-mono mode ensures you can still enjoy your music without sacrificing the intricate details of your favourite tracks.



 “I am using my Sonos Amp in a public space. Is dual-mono a better option to consider?”

The versatile nature of the Sonos Amp means that it finds use in a variety of applications, including placements in public spaces such as restaurants, hotel foyers and galleries. Speaker placements in any of these public spaces may require less emphasis on sound quality, but may still need to deliver both audio channels simultaneously in one concentrated area.


Will Dual Mono Mode Degrade Audio Quality?

For those concerned about losing out on detail, the good news is that your music’s clarity remains unharmed. But as both left and right channels are fed into a single speaker, the only noticeable impact will be the lack of stereo separation. 

However, if it’s any consolation, other Sonos products such as the One, SL and Play:1 models all deliver dual mono sound right from the factory. And if you are already familiar with these Sonos speakers, then you’ll know that they sound impressive in their own right. 

How Do I Switch the Sonos Amp to Dual Mono Mode?

If you believe that dual mono is the right audio configuration for your Sonos Amp and in-ceiling speakers, adapting the Amp is beautifully straight forward. 

There are no differences to how you wire up your speakers, or any need to lift the lid off the Amp and precariously tinker around inside. You don’t even need to touch the Amp to switch over to dual mono mode at all! 

Simply open the Sonos App on your iOS or Android device and follow the instructions below: 

  1. In the Sonos app, press Settings.
  2. Select System, then choose the room your Amp is in from the list provided.
  3. Press the Stereo/Mono option box.
  4. Then press Dual Mono to change from stereo to mono. 
  5. Now choose a music streaming service to play a song to test your Sonos Amp and speaker system. 

And now that your Sonos Amp and speakers are running in dual-mono mode, why not TruePlay your Sonos system to ensure the sound really is delivering its full potential? 

How Many Speakers Can I Connect to my Sonos Amp in Mono Mode?


The maximum speaker handling capacity of the Sonos Amp does not increase when configured for dual mono mode. 

Due to the impedance factors of the Sonos Amp, you may either connect 4x non-Sonos branded passive speakers (2x pairs), or a total of 6x Sonos-branded passive speakers. 

If you’re using 6x Sonos-branded speakers with your Amp in dual-mono mode, this means you have the potential to cater up to 6x rooms from one Sonos Amp. And if you are using a single-stereo speaker, such as the Sonance C6R SST or the Monitor Audio C-165 T2, then the Amp can retain its normal stereo operation instead. 

A maximum of 2x single-stereo speakers can connect to one Sonos Amp, or a combination of 1x single-stereo and 2x regular mono speakers. 

In Summary

We hope this helps you get the best sound from your Sonos Amp and ceiling speakers if you are unable to have a pair of dedicated stereo speakers or a single-stereo option. 

But if you wish to know more about the Sonos Amp and how to get the best from it, check out our further blogs on this incredible streamer and smart 125 watts-per-channel amplifier. Or if you wish to speak to one of the friendly Smart Home Sounds team for further advice and assistance, see the Contact Us page on our website. 

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