This review comes from me as a dedicated Sonos User. I personally have complete Sonos Home Theater systems in three (3) rooms. I like the convenience, sound and NO WIRES!
If you're trying to decide between Sonos 3.1 vs 5.1, just look at the sketched diagram in this post.
It shows a complete DD 5.1 setup which include Left/Center/Right speakers across the front, a sub and SURROUND (rear) speakers. In a DD 3.1 setup the surround (rear) speakers are not present. You only have the Left/Center/Right speakers and sub.
As you see, room size is irrelevant.
What you're getting with a DD 5.1 setup is full immersive sound (i.e. Surround) which is not possible with a DD 3.1 setup. The upside to starting with DD 3.1 is that you can expand it to DD 5.1 just by adding the surround (rear) speakers. So in essence it really comes down to your budget.
Remember Dolby Digital is a codec that is capable of carrying multiple audio channels (i.e. left front/center/right front_left rear/right rear and low frequency via a sub).
The only must components are the three (3) front speakers to begin experiencing Dolby Digital. The other components (rears and sub) can be added at anytime to get the full benefit of Dolby Digital audio.
To reiterate Sonos combines the left front, center and right front speakers into one unit which is either a Playbar, Playbase or Beam.
A word on sound quality
Let me tell you something right off the bat.
The sound quality performance you'll end up getting from a speaker will always depend on your room acoustics - particularly room dimensions and speaker positions.
The impact of the combination of these two is actually so strong that in most cases, it doesn't even make sense to utter a single word on sound quality without speaking of them.
This is also why it's not unusual to see completely different reviews of the same speaker.
In one case the speaker might be placed in a sweet spot inside the room and hence the user might be satisfied. In other cases the same speaker might be ill placed and hence user might even have returned it.
The point most people miss here is that it mostly isn't even about the engineering behind the speaker itself. It's about where you place the speaker inside which room.
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So, in order to solve this problem, I've partnered with an Acoustics and Audio Engineering PhD and created Soundton - a simple, 2D, browser accessible online speaker placement calculator.
With Soundton, now there's a way to figure the sound quality of most speakers before you buy them.
Read more about its working principles at soundton.com.
The end colormap provides you the locations with the best (green) and worst (red) acoustics.
ASAP Science also made a video on the loudest and quietest rooms in the world. A mind blowing example of the importance of acoustics (play time adjusted video below).
Other parameters such as the age/materials of the building, the furniture & carpets in place, etc can and will, of course, have an effect on room acoustics, too. But it's much less compared to other parameters mentioned above.
Also, while you're at it, blast my Hidden Electronic Gems list to test the speakers:
Anyways...
Now before we dive into the subject Sonos 3.1 vs 5.1 matter I think it’s important to understand the terminology.
What is Dolby Digital or DD?
Dolby Digital, also known as Dolby AC-3, is the name for audio compression technologies developed by Dolby Laboratories.
Also see: https://www.soundton.com/dolby-cinema-vs-imax/
That’s as far I’ll go in this narrative as it becomes more techy in a deep dive. The least complicated explanation in simple terms for Home Theater enthusiasts is that it’s a multi-channel audio format.
In home theater the most common full configuration is DD 5.1.
It consists of a Left, Center and Right speaker across the front of the listening area. These speakers carry the primary action and anchor the dialogue (via the center speaker) to the view screen.
There are also left and right Rear speakers. Those speakers commonly called surrounds are typically smaller in footprint than the front speakers. Rightfully so as they only handle a discrete channel in Dolby Digital sound that provide effects designed to immerse the listener in the action.
Their sole purpose is to give the illusion of continuous motion such as an airplane flying overhead in any direction, bullets buzzing by or a creaky door opening from the rear in a horror movie.
The diagram below depicts a typical DD 5.1 setup and the position of the listener/viewer. The dotted circle represents the encompassing audio.
Sound/effects from the Left/Right Fronts and Left/Right Rears travels to the listener in either a straight line or circular patterns left to right or right to left.
The sound from the Center speaker is typically straight forward with only an occasional left to right or right to left shift.
The Sub when positioned and tuned properly should for the most part appear not to emanate from any direction.
The speakers are generally wired back to an all-in-one Audio Video Receiver (AVR). Those with deep pockets may have separates consisting of an Amp & Pre-Amp and in some instances a discrete audio decoder.
It is because of the multi-speaker array (shown above) and the magic of Dolby Digital that Home Theater setups sound better than regular two channel stereo.
Home Theater enjoyment does not have to start with a cadre of five (5) speakers and a sub. One of the unique advantages of Dolby Digital is that it is expandable.
- One can start with Left, Center and Right speakers across the front for what is called DD 3.0 and later add a sub for DD 3.1.
- Another starting point might be Left, Center, Right speakers and Left/Right rears for DD 5.0 and finally add the sub to achieve DD 5.1.
There’s also Dolby Digital Plus.
You should know that Dolby Digital is gradually being replaced in cinema with Dolby Surround 7.1 and Dolby Atmos. Although, Dolby Digital Plus, Dolby Surround 7.1 and Dolby Atmos decidedly provide a much improved cinema sound experience; Sonos (at the time of writing this) only supports Dolby Digital.
Now that we know what components are required to enjoy Dolby Digital in home theater the question remains…
...why Sonos?
Sonos; although not the first with the general concept, combined the Left/Center/Right speakers into a sleek compact unit which they named the Playbar. To complete the listening experience Sonos developed their version of the sub-woofer and simply called it the Sonos Sub.
Although the concept was not different from the competition the implementation as a completely wireless system earned Sonos its reputation. To this day no competitor has been able to duplicate the Sonos success in the wireless home theater arena.
I must caution you that switching from a traditional wired home theater (with separate speakers) to a Sonos wireless system does have its drawback.
In my opinion, the Sonos home theater system when auditioned head-to-head against a separates system at the same price point (1,400 USD) will not sound as dynamic.
Mainly because using separates across the front they can be placed further apart for a wider more natural sound stage.
In all fairness all soundbars suffer the same limitations in terms of dynamics. The only area where some competitive soundbars have a slight edge (which I believe Sonos will soon rectify) is in their ability to decode Dolby Digital Plus or DTS.
However, those are becoming less of a demand with the advent of Dolby Atmos. The competitive offerings for soundbars that do decode
Dolby Atmos have yet to become totally mainstream for the average consumer. They aren’t cheap.
The DD 5.1 concept is the same for Sonos and its competitors that use separates. However, Sonos does it wirelessly and with only four (4) components versus six (6) wired components (see diagram above).
What else?
In the beginning a complete Sonos DD 5.1 system consisted of a Playbar, Sub and two rear speakers.
Since the introduction of the Playbar; Sonos has introduced the Playbase (that actually supports a TV where space is a premium). The Playbase contains the same speaker array as the Playbar.

Sonos has introduced the Playbase (that actually supports a TV where space is a premium). The Playbase (see image) contains the same speaker array as the Playbar.
The most recent addition to the Sonos home theater speaker family that encompass a Left/Center/Right speaker array is the Beam. It’s designed for smaller rooms such as a large Bedroom or mid-sized Den.
The most recent addition to the Sonos home theater speaker family that encompass a Left/Center/Right speaker array is the Beam (see image).
Connections
The Playbar and Playbase both connect to your TV via an optical cable. The Beam designed for smaller rooms actually has the most advanced technology.
It includes HDMI-ARC (CEC) connection that also allows you to control your HDMI-ARC (CEC) equipped smart TV via Alex or Google voice assistant. The Beam also supports connection to your TV via HDMI-Optical (this connection negates the voice control feature).
Another way to enjoy Sonos home theater is via the Sonos Amp (see image) using your own wired 3rd party (left/right) speakers upfront.
Another way to enjoy Sonos home theater is via the Sonos Amp using your own wired 3rd party (left/right) speakers upfront. Sonos sub and surrounds shown above can also connect wirelessly to the Sonos Amp.
Unfortunately, with the Sonos Amp you cannot introduce a 3rd speaker as a Center. The Center channel is created by the wired left/right speakers that converge to create what is commonly called a “Phantom” center channel.
Even so DD 3.1 and DD 5.1 can be experienced but at a slightly reduced level in the center. However, with the right 3rd party left/right speakers the experience can be just as engrossing as if there were a dedicated center speaker as with the Playbar, Playbase or Beam.
The following picture shows how Sonos speakers used as surrounds (rear speakers) might be placed in a typical seating arrangement.
Below are the available Sonos configurations:
- 3.0: Playbar, Playbase or Beam (all contain a left /center/right speaker which = 3 total)
- 3.1: Playbar, Playbase or Beam with Sub
- 5.0: Playbar, Playbase or Beam with two (2) Sonos speakers used as surrounds (Sonos One x 2 / Sonos One SL x2 / Sonos One & Sonos One SL / Play 5 x 2
- 5.1: Playbar, Playbase or Beam with Sub and two (2) Sonos speakers used as surrounds (Sonos One x 2 / Sonos One SL x2 / Sonos One & Sonos One SL / Play 5 x 2
The Sonos One and Sonos One SL are identical in appearance & acoustics and are the smaller speakers pictured in first picture above. The only difference is that the Sonos One SL does not offer Alexa or Google voice assistance.
The picture below is that of Sonos Play 5’s in stereo pair. Some use the Play 5 as a stand-alone speaker. Using two yields an incredible two channel stereo sound stage. Play 5’s used as surrounds IMO are overkill. Just compare them (for size) with the Sonos One’s shown above in the first picture of this article.
Tip: Save your money.
Final Comments
Sonos Home Theater setups allow an incredible cinematic experience for movies and general TV. You can also enjoy your favorite music, pod casts and more.
The surround speakers can be configured to act as FULL stereo speakers for music and auto-switch back to surround mode for movies. Additionally, the Playbase, Beam, Play 5, Sonos One/One SL and Sonos Amp support Airplay 2.
Note: Airplay 2 associated with the Sonos One/One SL and Play 5; as well as Alexa and Google voice assistants are muted when used as surrounds with the Beam as it handles those functions.
Hopefully, this novella (LOL) has provided a personal insight into the world of Sonos by a dedicated user. Learn more about Sonos and its incredible line of speakers in the link below.
In the meantime, enjoy and keep listening.
Sonos Home Theater: https://www.sonos.com/en-us/products/wireless-home-theater