Sonos state the following:

"We do not recommend wiring your speakers in series as it will result in poor sound quality”.
See this link:

https://support.sonos.com/s/article/4730

I’ve not personally tried this, but I suspect it would be best to heed their advice, otherwise you will likely be disappointed with the audio output quality.

Thank you. Honestly, I did read that also but was forgot to mention in my post whether anybody has tried it. I will follow what the experts say. Unfortunately, this means using this amp is not suitable in my scenario where i have 13 total speakers in the home speakers, all 4 ohms. I’d have to stack too many of these amps (unless I go on a full revamp of the speakers also). 

It may depend on what you expect from the resulting setup. If you’re wanting big sound levels then it probably won’t be a good solution, but if you want low- to medium- level output, it may be worth a try.

Probably the key thing is that all 4 speakers would need to be identical - if not you are likely to find that - say - the smaller speakers in a pair will produce disproportionately more sound than bigger ones.

Obviously there’s an element of risk in doing anything that the manufacturers tell you not to, but the load on the amplifier should not be significantly greater with two 4 ohm loads in series than a single 8 ohm load - so it may be worth just giving it a try to see if you can live with the sound.

If you decide to try it - let us know what the result is, please.

Speakers are referred to as 4 or 8 Ohms but this is basically a marketing thing. Speakers are actually more of a reactive (inductance and capacitance) than resistance device.

The designers of the speakers and amps know the reality and design their gear appropriately so all happily work well together.

When you chain two restive devices the new resistance is simple math, when you put reactive devices in series the resulting answer is very complex and often wildly different that the resistance numbers. You could see effective resistance as low as a fraction of an Ohm or as high as a couple dozen, all depending on the reactions of the crossovers an speaker coils. No realistic hope of an amp designer being able to deal with that.

Agreed - but… if you really are dealing with two pairs of identical speakers then I still think it could work out Ok. As we know, the Amp can handle a 4 ohm load Ok, so the impedance is likely well above that, even accounting for the fact that each may be far from a simple resistive load.

If they are not identical then your chances of success (i.e. a reasonably balanced output from both speakers in each pair) are low, in my experience.