Neighbor hears bass from my sub and Two Play:1s? -- do I swap to Two Play:5s?

Why don’t you just toggle the sub ‘off’, or maybe simply reduce its Volume/EQ Bass levels in the room settings? (Settings/System/[Room Name]).

That’s definitely possible. I was imagining since Fives produce more bass at ear level, less bass would travel through the floor? 

It’s not the floor the sound waves hit the wall and penetrate them.. but the sub goes lower freq so I think the five will be less offensive and you can tune down the bass if needed 

I’d be tempted to place the Sub on a rubber mat, so it didn’t make a direct connection with the floor. I’d expect some loss of bass out of that situation, but much less transfer to the floor itself, and the neighbors as a result. But that’s not a full solution, like @Ken_Griffiths ‘ is. 

I agree. The Sub is famous for not seeing water in a glass placed on it move when putting out bass, so I don't think this issue is caused by floor placement and will not be solved by delinking it from the floor.

I would first try Trueplay tuning of the set up if that has not been done. That eliminates bass bloat from the Sub makes the bass more tight and natural to the sound of acoustic bass music. Check with the neighbour what happens then. If that does not work, check again after dropping the Sub audio levels a couple of step below the default centre position.

I would not let go of the one pair + Sub combination in a hurry because of how well a properly set up system with those components can play all kinds of music.

There is also the possibility that a wall is picking up the sound and transferring it to the floor. Moving the Sub away from any nearby walls might do more for your neighbor than trying to decouple it from the floor.