You’d need to add an amplifier to take the signal from the sub output from the Sonos Amp, and power the  passive subwoofer. 

Some passive subwoofers are designed to accept Left and Right from the amplifier and pass the highs through to the satellite speakers. Airgetlam’s scheme will perform better.

Thanks, clear.

Isn’t there the risk of delay being added?

Usually amplifiers wouldn’t be adding a delay in a subwoofer signal, as there’s only amplification, and not any other signal processing. The line level output for the Sub on the Sonos Amp would be in sync with any speakers being driven by that Amp. 

Note that the sub outputs are turned off when the Sonos Amp is being used to drive surround speakers. In that case, it is only being sent/receiving the surround signal, and not any of the subwoofer data. 

@vannibombonato  It might be more helpful to give some more details about what you hope to setup.  What specific sub and speakers are you planning on setting up and for what size space.  If only a pair of speakers for a relatively small space, then the Sono Amp should have plenty of power and you could get away with using an impedance matching speaker switch between the Amp and your speakers and sub.

Also, there are mixed reviews on the effectiveness of outdoor subs, and some are designed to be used with specific speakers.  I’ve thought about using the Polk outdoor sub before, but they are designed for their specific Polk speakers.  I also have a larger space and would definitely need to and another amp to the setup. 

Everybody,

thanks for the help.

Here are some more details and further doubts:

• The space is an “L” rectangularly shaped, around 120square meters in all. As it has an irregular shape, i unfortunately feel that 2 subs would be needed to have a decent sound quality.
• The sub is not “needed”, i just feel it would be a nice add to the sound quality.
• I was looking at passive subs which are rated around 200-300W. In particular, Polk Atrium sub 100 (200W), and OSD Audio Forza 10 (300W).
• I am clear on adding an amplifier, but i then wonder how that would work with the volume controls, as the amplifier has its own volume which is not in sync with the Sonos Amp.
• At the moment i was thinking at using 2 or 3 Sonos Amps with matching Sonance speakers, but i’m struggling in understanding how/if such a setup could be easily integrated and managed with external Subs / Amplifiers. The idea is to have something that i just have to turn on and forget, if i have to mess with separate volume controls, etc., then it’s a no go.
• An alternative would obviously to connect a Sonos port to a separate integrated system with its own amplifier. My budget is around 5-7k, if anybody has suggestions they are more than welcome.

Sorry for the dumb questions but i’m getting lost in all the impedance, wattage etc. 

Thanks.

vannibombonato,

Keep in mind that the “room” outside is rather large and speaker systems that are perfectly adequate inside can be almost insignificant outside.

For your budget, Coastal might offer something of interest. 

The Volume control issue with 3rd party amplifiers is relatively easy to solve by using a Speaker level to line level converter. If you are or know an electronic nerd, level converters can be constructed for a few cents using some discarded (with one good end) RCA patch cords, a pill bottle, and a few resistors. Or one can purchase the converter inexpensively.

Do you think you’ll using both sides of the L regularly?  I would bet would side will get most of the activity while the other will not be used as much.  You could go with 1 sub at first, factoring in the ability to expand later if you wish.

The Polk is designed to work with other Polk, and may say it sounds poor otherwise.

I think 2 Sonos amps will be plenty, maybe even one.  I have 4 speakers running off a single amp in my yard with no issue with volume.  I think you’re yard is a little bigger than mine, and not in an L, but the point is that the amp puts out a lot of power.  Using Sonance, you can do 3 pair without an impediance matching switch.

I’ve done this as well and it works fine.  The main issue I had was that I could not connect TV audio through Sonos with this setup, not without a delay, so it complicated selecting input and volume control.  The Amp simplified it all.