Improving a Sonos 5.0 system

Bass, no, sub is the answer,surround, what sort of signal are you feeding the Playbar? It really only does surround when fed with dolby digital 5.1.

When playing a blu-ray movie like Pearl Harbor with 5.1 Dolby, the surround sound effects are definitely there, but...how shall say...muted.

Is there any way with the software to make 60%+ of the audio energy come from the back two Play 3's as they are handicapped by their positions on the floor?

I have adjusted the bass vs. treble such that the bass is favored, and moved the "surround" setting to max.

During setup did you configure the surrounds as being at the maximum distance from the listener?

What ratty is suggesting is that you trick the Play' 3's into thinking they are further away from the listening position than they really are. As such they will play louder natively. I use the same trick with my Play 3's as surrounds. That being said your "Spousal" issue is kill'n you :8

"We have a soundbar and a pair of Play 3's right and left behind the sofa where we normally sit, and on wood flooring pointed 45-deg to the television."

If I understand the above statement...the Play 3's sitting behind the sofa is degrading the sound as it can't escape to the open. You have three (3) placement options (as I see them) and you've got to reach a compromise with your spouse: Not quite sure what you mean by "pointed 45 deg to TV" since you say they are behind your sofa?

1. Place the speakers on Sonos stands
2. Move the speakers to the L/R sides of the sofa
3. Wall mount them to side or rear wall above your spouses head and line-of-sight and hope they won't be noticed

All jokes aside...surrounds by any manufacturer were not designed to be below ear level in a seated position. I hope you can find a happy medium.

Cheers!

Behind a sofa placement will only work for a Sub - the low frequency sound waves it puts out can easily pass through a sofa. Not so with the kind of frequencies a 3 will put out, where muted or muffled sound will be the outcome from behind a sofa placement. If they can't be at ear level, pointing them to where you sit will still work, as long as there is nothing between them and your ears.
See if spousal permission can be obtained for behind the sofa, out of sight, Sub placement. That will take things for effects laden movies to a whole new level.

Hi, acfalk. I'm afraid that beyond "tricking" the PLAY:3's into think they are a greater distance from you than they actually are, there is little you can do. As with many things in audio technology, a speaker will only truly live up to its potential, given the appropriate placement. As far as adding bass response, it'll be the SUB that makes the ultimate difference.