Sunday, June 30, 2019

Sonos Playbar, an "old" TV, and Dolby 5.1

My wife got me a Sonos Playbar for my birthday.  I was reluctant to accept it, because the 1980s Acoustic Research speakers I have and my old Onkyo receiver were working just fine!

I installed the bar underneath my TV and was blown away by the clarity and volume -- the old speakers and receiver had to go.  I also bought the Sonos sub, because bass.

After playing with the speaker for a while I realized the following:
  • With the optical IN to the Sonos coming from my TV, and only when using the TV's internal tuner (I am a cord cutter), I could see (using the "Settings --> About My Sonos System" option in the Sonos phone app) that the bar was receiving a Dolby Digial 5.1 surround signal.
  • When I switched to my Roku streaming box, which goes to the TV via an HDMI input, the Sonos would only receive Dolby Digital 2.0.  This was the same for any device I connected to the HDMI input.
My original setup, which didn't provide Dolby Digital 5.1 to the Playbar unless using the TV's internal tuner

What I found out was that older TVs will not pass the Dolby Digital 5.1 signal through from HDMI.  For whatever reason, the signal will be stripped by the TV.  Newer sets apparently don't have this problem.

I also found out that devices like the Roku don't support Dolby Digital 5.1 anyway -- they only support a different standard called DTS Digital Audio.  DTS is a competing format, all of the differences between Dolby Digital and DTS are explained here.

The Sonos Playbar does not support DTS, so we need to make sure to provide the Sonos Playbar with a Dolby Digital signal.

Really, there are two problems:
  • An old TV that strips the surround signal from the HDMI input
  • A streaming box that doesn't support Dolby Digital 5.1

There is no single solution for both problems.  Purchasing a new TV would probably (after careful homework) not strip the surround information from the HDMI input.  However, a new TV isn't an option for me.  I paid dearly for this TV in 2010, and it is staying on my wall until it dies.

It turns out that there is a box that will strip the Dolby information off of the HDMI input, and route that signal to its own optical digital output.

J-Tech Digital 5 Port HDMI Switch & Audio Extractor

For streaming, the Amazon Fire TV Cube supports Dolby Digital 5.1.  It has the capability to transcode DTS (which most streaming providers support) into Dolby Digital 5.1.  

Amazon Fire TV Cube
The only downside to this device is the continual feud between Google and Amazon, so you will lose YouTube and Google Play video support.  (Update: It looks like the feud is ending?)  

To continue to use the Google Play movies that you purchased, you can use a service like, which will aggregate movies that you've paid for from different providers and let you view them all under one roof.  Note, this is supported for most movies, but not all

Make sure you tell the Fire TV Cube to always use Dolby Digital, you'll find this in the settings for the Fire TV Cube as below:

Configure Fire TV Cube to always output Dolby Digital
I've noticed that *some* providers don't give you the surround until you turn it on explicitly. is one of those providers.  So, keep an eye on your Sonos phone app to see what the Playbar is receiving:

The "About My Sonos System" dialog on my Android phone, indicating what type of signal the Playbar is receiving

My new setup looks like this:
The new setup uses the J-Tech HDMI switch to strip Dolby Digital signals from HDMI inputs and pass them to the Playbar via its own optical digital output

The J-Tech HDMI switcher in service
The only remaining problem with this setup is the internal TV tuner.  If I want to watch OTA TV, I have to connect the optical output from the TV directly to the Playbar.  This might be solved by adding a separate TV tuner device, like this one (that also provides recording capability).  There are also several devices that will provide one or two TV tuners, and make that TV signal available for streaming by your laptop, TV, phone, etc.  The Amazon Fire TV Recast is one such device.

I hope this helps you with your Sonos Playbar setup.