There are quite a number of options here, but I would perhaps choose to put an Amp and two 8ohm floor-standing speakers in the room. Ideally have the mid-range speakers set at shoulder/head height and positioned to form a triangle with where you sit on the opposite side of the room (so roughly at 1/3rd and 2/3rd along the length of the longer wall) and definitely add a Sub (gen3) for music audio.  

I guess you could always then add two more identical 8ohm speakers later, if you felt that you needed even more sound, but personally I think two speakers would be enough, together with a Sonos Sub to fill the room, or instead/aswell, just add another Five to the existing Five, but set those at head height too.

Then use the Five (if not using) and the ‘One’ elsewhere in the Home.

Everyone’s idea of “fill the room with sound” is different. If you want to create an orchestra sensation, then you’ll need a pair of speakers and the best impression of an orchestra will occur when you are seated approximately as far from each speaker as the speakers are from each other and the speakers should be at ear level. If you want to create a “wash of sound”::, then multiple speakers, mounted higher than ear level, is the best approach. Multiple speakers distributed throughout the room also improves the situation created in long narrow rooms where speakers at one end will be too loud for listeners near the speakers and not loud enough for listeners at the far end.

Your proposed configuration would not be wrong. The the FIIVE’s would be too far apart for good stereo imaging and the ONE’s would tend to dominate for listeners on the couch if they are close to the couch. In this case you’d want to run the couch speakers at a much lower level.

Why are you thinking of using an AMP? Do you have some third party passive speakers that you want to incorporate into the room?

If you are a bass freak, SUB is a great addition.

Ugh, sub not amp…. I meant sub. I am not a “bass freak” I just want to get the best sound that I can. And don’t know really how to go about that. I was only thinking the sub so it would pull the low end from the rest of the speakers and let them do their thing. I guess I am going for more of a “wash of sound” where it sounds even on either side and in the middle. 

As I am writing this, I have some music on, coming through the five and one. My ears are fighting to tell exactly which speaker is doing what, even if I’m not thinking about it. They are at each end of the short end and pointing longways, if that makes sense. I have the volumes adjusted so that the sound is even, ie the one is turned up more than the five. Although my ears are doing a WTF thing, it does sound ok right now. 

If I do go and get another five, or I guess this applies to any speaker, how far apart should they be for proper stereo imaging?

If you want to flood the entire room with Sound then maybe do this (see attached) and use the Sonos Five elsewhere - or I guess you could go all-out with 4 x Fives instead (and use the original Sonos One elsewhere), but in either case, I would add at least one of the larger Sub in one of the corners of the room - or even maybe add two Sub-Mini’s, one each, in opposite corners. 

The Subs should be placed on the floor and all four speakers should be set at head height when seated.

(Sorry that my sketch is a bit rough and ready). 

This is how the room is set up, and we have a roughly 14’ ceiling, vaulted ceiling in it. Would the sub work where I put it in the bad drawing? Their is an overhang that runs above the two openings on the bottom. The roof and walls are all log, except where the toy box and chair are. 

The above is what my original plans were. But you say move everything closer into the center of the room? If I only go with two fives, would I be better to mount them along the right wall in the picture to send sound down the room?

Do you often sit and listen to music or are you mostly “out and about”? When (and if) you sit and listen, where do you sit?

I’d say 70% is moving around, the rest is sitting and listening, or watching a movie or show on the ipad, which we airplay straight into the speakers as is. 
 

I went with sonos for the sole reason of being inside/outside, and having the same music playing everywhere. A move and more speakers are in the buy list. But I’m just asking slowly. We live in the north, so outside listening is quickly coming to an end. I do want a move for the master bedroom and then to drag outside in good weather. 
 

I should have added all those speakers etc is where I was thinking of placing things. Currently the five is next to the chair on the left short wall and the one is in the upper right corner. 
 

We use all chairs and the sofa equally I think. 

Duplicate 

The speaker arrangement shown in the drawing favors listeners sitting on the sofa and listeners moving around. For sitting in the left chair, I think that you would like both FIVE’s along that short wall and the ONE’s opposite. I’d also recommend moving SUB closer to the plain of the FIVE’s.

In the end only you know what sounds “best” (to you). Feel free to experiment and discover what is “best”.

So I since added a move into the house. It lives in the master bedroom, but I drag it outside when I am cooking, and place it on some old suitcases next to the chair in the bottom of the picture above. Now with that said, I have the volume se for the 5 and the 1 where it sounds even through the room, when I bring the move in, it is as if it helps fill the room. My ears are no longer fighting to find out where any sound is coming from, and you can just hear things really full. What if any benefit will I get from adding another 5, a one, and the sub gen 3? I listen to some jazz (Art Pepper), Rock, folk, country/western, red dirt, Irish music, and other stuff, but those are mainly what will be on. Will a sub help any of that? 

If your goal is to have even loudness throughout the area, multiple speakers are helpful. If you want to create the illusion of an orchestra at a favorite listening position, symmetry is helpful. You would want to be approximately as far from the L/R speakers as they are from each other and the L/R speakers should be identical. The amount of bass is a personal preference. “Bass freaks” appreciate SUB very much. Another, much subtler benefit of a SUB is clearer midrange because the L/R speakers have a simpler job since the bass is handled by SUB.

Only you know what sounds “best” (to you).