Hi
The question is often asked “does a Sonos Sub improve the listening experience of Sonos speakers”. IMO the answer is “Yes”.
The more prudent answer given by community members (in most cases) is to suggest that the person asking the question allow their ears to make the final judgement. Meaning…purchase a Sonos sub and return it within the Sonos return window for your region; if not satisfied. In the US the Sonos return window is 45 days. You can also do the same from a local or online retailer that offers a reasonable return policy/window.
Sonos speakers (IMO) are great but none offer the low-end that I prefer...not even the excellent Sonos Five. However, there are considerations.
As you are aware Sonos offers a full size sub and now after much lobbying by community members the Sub-Mini. Both subs serve a specific purpose for their intended use. Before I go further…to keep things simple in this discussion…”Cost” is not a factor of consideration regarding the full size sub versus the sub-mini.
IMO there are use scenarios wherein the full-size sub may serve you better than the sub-mini and vise versa. For my purposes the full-size sub is a home theater product. The sub-mini is more applicable for music listening. However, that’s not to say (given the multitude of possible variables that may come into play) that the suggested use scenario for either sub might be reversed.
I’m not a “bass-head” when it comes to music. I prefer a flat-line that allows the music to be heard as it was originally recorded with very little coloring. That said I’ve found a sub-mni to be an excellent speaker to carry the low-end when listening to music.
I have two Era 100’s set as a stereo pair bonded to a sub-mini in my garage which is 27 x 25 feet with 10 foot ceiling. The Era 100’s are 6 feet apart mounted on a wall 8 feet above floor level. I can definitely hear the difference if I remove the sub-mini. The sub-mini sits in a corner. IMO a full-size sub would have been over-kill however as I said I’m not a “bass-head”. I also have a pair of Era 300’s bonded to a sub-mini that sits behind a sofa that delivers plenty of low-end for traditional stereo and Dolby Atmos spatial audio music.
I watch a lot of movies with Dolby Atmos sound tracks. So much so that I have a media room with Arc, Era 300’s as surrounds and dual full size subs. I really want to hear and feel the explosions and/or any noise intended for the low-end spectrum. I have a similar setup in another room and in my bedroom. Similar for those rooms means that only one full-size sub is used. A sub-mini would have sufficed for the bedroom but I had an unused full-sized sub available. Just to add…a Sonos sub of any size will improve the dialogue for a Sonos soundbar be it an Arc, Beam2 or Ray.
The bottom-line here IMO is that a Sonos sub (full-size or mini)_given your preference for low-end be it a lot or a little in a particular use scenario_ is well worth the investment.