How to Play Hi-Res Audio Files on Sonos

It is possible to play high resolution 192 kbps 24 bit (or 96 kbps 24 bit) files on your Sonos system, sort of. This depends on downsampling the files, but more importantly hinges on the unpublished capability of Sonos to support 48 kHz / 16 bit / 1536 kbps, higher than the officially stated 1411 kbps. So why does this matter? It matters because 1.088435374 is an ugly number.

Sonos continues to add to its impressive arsenal of supported streaming services, including Deezer Elite and Tidal which depend on a 1411 kbps (kilobits per second), and I commend them for it. 1411 is CD quality, based on the CD sampling rate of 44.1 kHz and 16 bits of resolution for 2 channels (44100 x 16 x 2 = 1411200 bits per second). There is no data compression, and no loss of quality relative to the original proven CD format, compared with many streaming or audio file formats that run at lower rates, usually making the sound fuzzier or crunchier. “Lossy” data compression mostly affects the sense of clarity and delicacy in the sound, and is very different from the changes you get from an upgraded audio system, or changes to room acoustics, for that matter.

Slam dancing to Sonos Play:1

Dancing with the Sonos

My concern is that high resolution files are generally available at 192 kHz or 96 kHz sampling rate, 24 bit resolution, higher than is supported by Sonos (as of now). Software like XLD lets you downsample to anything you want, and if you follow Sonos’ instructions, you’ll be going for 44.1 kHz / 16 bit to get to 1411 kbps. Don’t do this. It results in division by the extremely uncool number of 1.088435374 (or a multiple) which can’t result in the cleanest mathematical conversion. That number is 48 divided by 44.1. Go for 48 kHz / 16 bit, or 1536 kbps, and your audio will be happier. (It’s cleaner to divide 192 or 96 by 48, than to divide any of these numbers by 44.1. Also, some hi-res audio files are multiples of 44.1 kHz to start with, like 88.2 or 176.4 kHz; for these, downsample to 44.1 kHz.)

Can you really hear the difference?

I wouldn’t necessarily put money on it, and I can assure you sound quality is much more significantly affected by mixing/mastering/equalization and the number of copy and conversion generations than the ultimate data rate. Don’t buy high res files if you are only going to downsample these to play on a Sonos. Just pay less for the CD-quality versions in the first place (and by this, I mean lossless versions). On the other hand, if you are a digital audio file junkie, and anticipate (likely correctly) that the future Sonos PLUS Gen II Turbo platform will handle all sorts of higher bit rates, or you use another system that DOES play these Hi-Res files (there are a lot of such systems), then go for it, and do your conversions in the least mathematically convoluted way.

How do you do this downconversion? The software I was using, XLD on Mac OSX, lets me do this in two steps. Step one, I convert the 192-48 or 96-48 file (usually FLAC or AIFF or WAV format) to WAV or AIFF format, specifying 48 kHz sampling rate, 16 bit resolution. This results in the 1536 kbps rate (48000 x 16 x 2 = 1536000). This plays fine on Sonos. Am I done? Keep reading.

A word about Wi-Fi and SonosNet™

So what happens on Wi-Fi with Sonos, anyway? If you are a long-time user of Sonos this doesn’t apply to you (as much), because you surely have a system set up to use Sonos’ very capable mesh-network wireless system, which is pretty robust. Sonos now supports 2.4 GHz Wi-Fi, so a lot of new users start out directly on Wi-Fi, not using SonosNet. I have tested such a system at home, using between 1 and 6 different Sonos systems playing different files. When I play these higher rate files, a Wi-Fi based Sonos system doesn’t easily handle more than a couple simultaneous streams. This is a very UN-scientific analysis, because there are a lot of other factors at work that could be affecting my throughput, such as the fact that I live next door to a microwave oven factory. Switching to SonosNet, I can reliably run more (double, at least) simultaneous streams of these relatively high bit rate audio files. Sonos steers anyone with Wi-Fi difficulties to their SonosNet solution.

In our house, we use the 2.4 GHz device to cook food.

In our house, we use the 2.4 GHz device to cook food.

This leads to step two of the downconversion – convert the lower rate WAV or AIFF file into a FLAC or ALAC file, also at 48 kHz, 16 bit. While this is still outside the official Sonos safety net (“Sonos supports FLAC files up to 16 bit / 44.1 kHz,” from their website) it does result in a lower data rate in the 1030 kbps range, and this roughly 33% reduction helps a lot in wireless robustness for either Wi-Fi or SonosNet. For all I know, Sonos will change the official max rates to 48-16 next week… we’ll see.

Happy listening!

BREAKING NEWS: If you are into high-res audio, see my review of the Oppo HA-2SE DAC Headphone amp – excellent audio for your iPhone or Android – especially if you have the new iPhone 7 / 7s without a headphone jack. The Oppo handles all kinds of formats, from FLAC to Ogg-Vorbis to DSD over PCM (DoP).

If you are interested in Sonos, see my series on…

Sonos Playbar

Sonos Play:1

© Copyright 2015 Stephen Shenefield

9 thoughts on “How to Play Hi-Res Audio Files on Sonos

  1. “On the other hand, if you are a digital audio file junkie, and anticipate (likely correctly) that the future Sonos PLUS Gen II Turbo platform will handle all sorts of higher bit rates, or…”

    Yeah – good luck with this. We have literally been BEGGING SONOS to support hi-res FLAC files (192/24 or 96/24) for YEARS! From what I can see, and I have spoken with them personally, they have very little interest in satisfying what they perceive to be a “fringe” request. The SONOS “audiophile” community has been requesting a product like the current CONNECT with a 12 volt trigger, NO internal DAC (coax and optical out only) and full support for hi-res FLACs. They have not come through for us at all. As much as I do like SONOS, I will drop them like a “hot potato” and sell all my gear when something “hi res friendly” that is priced right and works in a seamless and reliable way is marketed in the USA.

    • Here here! It’s not actually mentioned in their sales blurb etc and I had assumed being labelled the “Rolls Royce” of music players in a couple of reviews that it would *obviously* handle my 24bit 96/192Khz FLAC files. Oh dear – just bought my first Sonos Connect and very disappointed to find it won’t play any of my many 24bit tracks. So I’d need to downsample a load of music to play it on Sonos. Am considering sending it back but what to get instead… the Bluesound range looks good and definitely does support 24bit and 192Khz, but the Bluesound NODE 2 which is the equivalent of the Sonos Connect, is twice the price…

      • Take a look at the Node II by Bluesound – looks like they are going to fill the high bit-rate void in the Sonos product line. Really innovative. I just picked up the Power Node 2. No regrets so far.

  2. There’s another way folks!!! At least for Mac Users.

    The ingredients:

    1. Mac OS X
    2. VLC Player for Mac
    3. NiceCast
    4. Sonos Player
    5. A sprinkling of Hires files (FLAC, DXD, ALAC, whatever)

    Cooking Instructions:
    1. Download and install the items 2, 3
    2. Start VLC and load your files in [5] above
    3. Start NiceCast
    4. Click on Source and select VLC in Nicecast
    5. Click on Share and copy the Local URL starting with http://xxx.xxx.xxx.xxx:8000/listen.m3u
    6. Click on Start Broadcast, make sure ‘ON AIR’ is shown in Red
    7. Start Sonos Player (controller for Mac)
    8. Go to the Sonos Menu and select Add Radio under the Manage tab
    9. In the Streaming URL box, paste the URL in [5] above
    10. Give it a name in the Station Name box under it, say ‘NiceCast’ for example
    11. Click the OK button
    12. Select ‘NiceCast’ under Radio -> My Radio Stations
    13. Click play, and voila! Hires Audio plays via SONOS

  3. Another way to play high quality flac files is to use the line in feature, Play 5 has one, I’m not sure abot other models.
    Play song on device fitted with Dragonfly, or similar, USB DAC

    • You are correct, feeding a fancy DAC analog to the Sonos input would work, but then you are going into the Sonos ADC (analog to digital convertor) which I am sure is fine quality, but you are adding more steps and an unneeded analog step (the wire). At a minimum this will add noise. Transcoding the audio in the digital realm will be better.

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