Jump to content
  • The Computer Audiophile

    The Sonos Port Isn't Bit Perfect

     

    As the title says, the Sonos Port isn't bit perfect. What's the big deal? For many Sonos users this is a non-issue because they are streaming from very lossy services such as Apple Music or Pandora. However, for people who care about sound quality, this is a big deal because the music sent though the Sonos Port has been digitally processed before anyone gets to hear it. Before digging in further, let's take a step back and define some terms and explain some additional details. 

     

    port-front-angle.jpgSonos is mostly known for its speakers, but the company has also always offered a component with built-in digital to analog conversion and a digital audio output. The Sonos Connect was the previous generation of said component, and the Sonos Port is the current version. I have both components in my listening room, connected to the same system for testing. 

     

    These Sonos components with digital outputs have always been terrific for those of use seeking high quality audio because we connect the digital output to the DAC of our choice and send the signal on to our refined audio systems. Many audiophiles I know do this as well as tons of custom installers around the globe have connected these Sonos components to outboard digital to analog converters. The reasons for this are that Sonos has the most content (think the regular services, but also Pandora and SiriusXM) and the products work very well. Connecting the Sonos Port to an outboard DAC can elevate the audio performance to another level because the internal DAC is somewhat limited. 

     

    What is bit perfect and why should I care? In the simplest terms, bit perfect means that the audio hasn't been changed. The music sent into the component is the exact same music that comes out of the component. If you care about high quality, getting the lossless streaming you're paying for from Qobuz, Tidal, Amazon Music, etc... or about playing a local library of ripped CDs without unknown signal processing taking place, then you should care about bit perfect because without it you have no idea what's happening to your audio. If this isn't a concern for you, no worries. 

     

    port-back-angle.jpgThe Sonos Connect and the Sonos Port both have settings that are supposed to enable digital audio to traverse through the units without any digital signal processing. The Connect works as it should and outputs bit perfect audio without an issue. The Port on the other hand, can't output audio without some type of signal processing taking place inside the unit. 

     

    To test this, I setup both the Connect and the Port identically. Both units were set "Fixed" Line-Out Level. Even though the terminology suggests this line out is the analog output, it also effects the digital output, as seen in my testing. Fixing the output level just sets the volume to 100% and prevents the Sonos from reducing bits to reduce the volume of the music. When this is set, the EQ can't be adjusted. I looked through all the other settings and made sure there wasn't enabled anything that could change the sound. Both units were identical.

     

    Keep in mind that the Sonos S1 app is used to configure the Connect and the new Sonos app is used to configure the Port. This shouldn't be an issue because the settings are the same no matter which app sets them and the audio being sent to the units doesn't route through the iOS app or desktop apps. 

     

     

    Sonos Port Issues 01.jpg Sonos Port Issues 02.jpg 

    Sonos Port Issues 03.jpg Sonos Port Issues 04.jpg Sonos Port Issues 05.jpg

     

     

     


    Testing Methodology 

     

    Once the units were setup, I use the following testing methodology to determine that the Port wasn't outputting bit perfect audio. 
     
    I use a Berkeley Audio Design Alpha DAC Reference Series 3 that identifies and decodes HDCD on all sample rates. When an unaltered HDCD file is played, the HDCD indicator on the DAC is illuminated. The HDCD flag is on the 16 bit for CD files and the 24th bit for high resolution files. Any alteration, DSP, volume leveling, etc... changes this least significant bit and won't enable the HDCD indicator to illuminate. Given the Sonos units only support 16 bit / 44.1 kHz audio, I only tested this resolution. That's the hardware piece. 
     
    With respect to source files, here's what I do. 
     
    I have a list of roughly ten known HDCD albums (although I could use more if needed). Many of these albums were only released as HDCD encoded CDs/files. There is no alternate lossless version. For example, Reference Recordings only releases CDs that are HDCD encoded. 
     
    I set a baseline by playing my own local copy of the albums and make sure the HDCD indicator illuminates.
     
    I used the Sonos applications on iOS and macOS for playback during this test. 
     
    Through the Sonos apps and the Sonos Connect, I streamed my known HDCD releases first from my local ripped CD copy, then through Qobuz, then through Tidal, and finally through Amazon Music HD. I wanted to use my local file baseline, then a few streaming service baselines.  

    Then I tested the Sonos Port using the same procedure. Local files followed by streamed versions from the lossless services. 
     
    Absolutely there are possible holes in my methodology, but I believe I've minimized them as much as possible. I also reached out to Sonos in an effort to check my methodology and show them the results, but I didn't receive a response. 

     


    Test Results

     

    Using the Sonos Connect, everything I sent from my locally stored ripped CD and all the streaming services was bit perfect. As long as the Connect was setup correctly, I couldn't get it to fail. Bit perfect every time. 

    Using he Sonos Port, I couldn't get it to pass a bit perfect audio stream no matter what I did. In other words, it failed every test. Local stored ripped CDs and streamed music from all the lossless services were all altered between the time they entered the Sonos Port's ethernet input and the time they extend the Port's coaxial digital output. 

     


    Conclusion

     

    Take this for what it's worth. Some people won't care, while others will want to look for better solutions. I highly recommend the Bluesound Node 2i as a replacement for the Sonos Port. The Bluesound ecosystem doesn't have Pandora or SiriusXM, but for most people it has everything they need and it's bit perfect with local and streamed content in all supported resolutions up through 24/192. 

     

    Perhaps Sonos will explain what digital signal processing is taking place inside the Port or even issue an update that enables users to turn off this DSP and output bit perfect audio. Until such time, the Port is a hard pass for me. 

     

     

    Sonos Port HERO.jpg



    User Feedback

    Recommended Comments



    My guess is that the target market for this device would be hard pressed to understand the issue here and very likely would not care at all even if it was fully understood. My other guess is that the SPDIF digital output is rarely used by any owner of this device. No one would purchase a device like this for serious listening when there are now many other good choices for that purpose.

     

    I doubt the manufacturer will respond as I think the most likely thing happening is some form of volume leveling. People who buy these are going to use it mostly to serve background music and don't want wide fluctuations in volume. This is nothing more than a guess I admit but from friends I have known who have these types of devices I suspect this is it.

     

    Good for you for pointing it out.

    Share this comment


    Link to comment
    Share on other sites

    Thanks for doing this! I have somewhere around 10 Sonos zones in my home. 5 of them have external DACs and of those, 3 are in serious listening systems. To be fair, a lot of my serious listening is vinyl or CD, but I also do a lot of Tidal listening. Of the 3 important Sonos boxes, 1 is a Connect modified by Wyred 4 Sound, 1 a Port modified by W4S, and 1 a regular Port. All 3 use Audio Note (UK) DACs.

     

    Moving away from Sonos takes away all the nice options of multi-room play - or at least having to replace ALL the Sonos boxes. I also have a Roon system, but it will not let you group a Sonos device with a non-Sonos one (I suspect because it is using the rich Sonos control protocol).

     

    So although bobflood's prediction is probably right, I would certainly love to see the switch to turn off any DSP.

    Share this comment


    Link to comment
    Share on other sites
    2 minutes ago, NapaBob said:

    Thanks for doing this! I have somewhere around 10 Sonos zones in my home. 5 of them have external DACs and of those, 3 are in serious listening systems. To be fair, a lot of my serious listening is vinyl or CD, but I also do a lot of Tidal listening. Of the 3 important Sonos boxes, 1 is a Connect modified by Wyred 4 Sound, 1 a Port modified by W4S, and 1 a regular Port. All 3 use Audio Note (UK) DACs.

     

    Moving away from Sonos takes away all the nice options of multi-room play - or at least having to replace ALL the Sonos boxes. I also have a Roon system, but it will not let you group a Sonos device with a non-Sonos one (I suspect because it is using the rich Sonos control protocol).

     

    So although bobflood's prediction is probably right, I would certainly love to see the switch to turn off any DSP.

     

    Thanks for all the info NapaBob. There are quite a few people in the same boat as you, using Sonos in pretty revealing systems. The content Sonos delivers is second to none. The user interface and ease of use is pretty good as well. 

    Share this comment


    Link to comment
    Share on other sites
    2 hours ago, NapaBob said:

    Thanks for doing this! I have somewhere around 10 Sonos zones in my home. 5 of them have external DACs and of those, 3 are in serious listening systems. To be fair, a lot of my serious listening is vinyl or CD, but I also do a lot of Tidal listening. Of the 3 important Sonos boxes, 1 is a Connect modified by Wyred 4 Sound, 1 a Port modified by W4S, and 1 a regular Port. All 3 use Audio Note (UK) DACs.

     

    Moving away from Sonos takes away all the nice options of multi-room play - or at least having to replace ALL the Sonos boxes. I also have a Roon system, but it will not let you group a Sonos device with a non-Sonos one (I suspect because it is using the rich Sonos control protocol).

     

    So although bobflood's prediction is probably right, I would certainly love to see the switch to turn off any DSP.

    @NapaBob sorry but I forgot about the W4S modified units. Of course those would be the most likely to be used with an external DAC. This was especially true from the early days when Sonos had exclusives on content at 44.1/16. I almost bought one myself.

    Share this comment


    Link to comment
    Share on other sites

    HDCD has to be supported by the DAC, maybe the port doesn't support the extended low level flags and ignores them. Port has to be bitperfect I just bought one because I read that they had fixed the bitperfect issue 😁

    Share this comment


    Link to comment
    Share on other sites
    52 minutes ago, DK11706 said:

    HDCD has to be supported by the DAC, maybe the port doesn't support the extended low level flags and ignores them. Port has to be bitperfect I just bought one because I read that they had fixed the bitperfect issue 😁

    There’s no such thing as extended low level flags. 
     

    I hope they fix the issue. 

    Share this comment


    Link to comment
    Share on other sites

    Well HDCD have a control signal, and only works if supported by the player, so my point is still valid :-)

    Share this comment


    Link to comment
    Share on other sites
    Just now, DK11706 said:

    Well HDCD have a control signal, and only works if supported by the player, so my point is still valid :-)

    No. 

     

    HDCDs played bit perfectly by any digital output into an HDCD DAC, will light up the HDCD indicator. It's the same for DTS signals. If the component can pass bit perfect signals, the DTS component will see it and indicate it's DTS.

    Share this comment


    Link to comment
    Share on other sites

    I did a quick catch up on HDCD and I have to admit that you are right and I'm wrong, the HDCD data is hidden in the last of part of the 16Bit, so if Sonos was bitperfect it should be passed and detected by your DAC.

     

    Anyway thank you for a great find, I already requested a return for my product and replaced it with my old trusty ZP80. 

    Share this comment


    Link to comment
    Share on other sites
    1 hour ago, DK11706 said:

    I did a quick catch up on HDCD and I have to admit that you are right and I'm wrong, the HDCD data is hidden in the last of part of the 16Bit, so if Sonos was bitperfect it should be passed and detected by your DAC.

     

    Anyway thank you for a great find, I already requested a return for my product and replaced it with my old trusty ZP80. 

    Thanks for the follow up @DK11706

    Share this comment


    Link to comment
    Share on other sites

    Sadly not surprised.  I bought my wife a Sonos speaker and found it unlistenably harsh--not in the audiophile sense, I mean compared to a cheap boom box, car stereo or similar.  I'm a hard pass on all their stuff

     

    Share this comment


    Link to comment
    Share on other sites
    1 hour ago, Tamarin said:

    Old news. Even the Connect is no longer bit perfect as of units manufactured in 2011 on, with hardware version 1.16.5 or higher (assuming that you keep it updated firmware-wise)

    https://en.community.sonos.com/components-228996/connect-no-longer-bit-perfect-6738927

    I got rid of all my Sonos gear because of this.

     

    I can confirm that my Connect manufactured in April 2013, and hardware version 1.16.5.5-1.0 is 100% bit perfect. 

     

    IMG_0337.jpeg

    Share this comment


    Link to comment
    Share on other sites

    Hi,

     

    I did some testing today, and I can confirm that both my Port and ZP80 are not bitperfect. My new DAC arrived today and works great with all material using my laptop.

     

    When I connect Sonos to my DAC it locks to 44.1 Khz and stays there even when feed 48Khz material, so I guess sonos downsamples everything to 16Bit /44Khz.

     

    One odd thing I did notice and maybe can be part of the bit perfect problem, is that you are still able to control max volume even with fixed output enabled.

     

    Cheers..

    Share this comment


    Link to comment
    Share on other sites
    1 hour ago, DK11706 said:

    Hi,

     

    I did some testing today, and I can confirm that both my Port and ZP80 are not bitperfect. My new DAC arrived today and works great with all material using my laptop.

     

    When I connect Sonos to my DAC it locks to 44.1 Khz and stays there even when feed 48Khz material, so I guess sonos downsamples everything to 16Bit /44Khz.

     

    One odd thing I did notice and maybe can be part of the bit perfect problem, is that you are still able to control max volume even with fixed output enabled.

     

    Cheers..


    I believe both products max out at 44.1 don’t they?

    Share this comment


    Link to comment
    Share on other sites

    I contacted Sonos support and they told me Coax supported bit depth is 16-bit/24-bit (44.1kHz/48kHz, FLAC/ALAC). 

    Share this comment


    Link to comment
    Share on other sites
    13 minutes ago, DK11706 said:

    I contacted Sonos support and they told me Coax supported bit depth is 16-bit/24-bit (44.1kHz/48kHz, FLAC/ALAC). 

    Oh very interesting. I will test those sample rates as well. 

    Share this comment


    Link to comment
    Share on other sites

    I contacted Sonos support again and was passed on to some senior people. Coax is only 44.1.Khz output, 48Khz is internal processing only.

     

    That is very bad news as the old connect was terrible at down sampling introducing tons of noise in the signal. They still claim that 16bit 44.1Khz is bitperfect, but we already know that it's not true.

     

    They will change the spec. in the link as soon as possible...and my Port will be returned.

    Share this comment


    Link to comment
    Share on other sites

    IMO, after the bricking incident, I would not want to support Sonos.

     

    It would be like voluntarily banking at Wells Fargo.

     

    Did I say IMO?

     

     

    Share this comment


    Link to comment
    Share on other sites

    I would guess that 90% of the installed base of Connect and Port devices are only connected using the analog inputs and/or analog outputs. Another way you may want to test the Port would be to factory reset it and added it to your S1 system and run the tests again. It would be interesting to see if the Port behaves differently on the S1 system.

    Share this comment


    Link to comment
    Share on other sites



    Create an account or sign in to comment

    You need to be a member in order to leave a comment

    Create an account

    Sign up for a new account in our community. It's easy!

    Register a new account

    Sign in

    Already have an account? Sign in here.

    Sign In Now



×
×
  • Create New...