Saturday, March 10, 2018

Music streaming services and sound quality

Back when I was a teenager I spent a whole lotta time on listening to music. I mean really listening - not just keep it running in the background while doing other stuff. First, I had a radio alarm clock with (cassette-)tape recorder. So I mostly listened to tapes which where recorded from radio. Of course the quality of those recordings and of the tape player itself would not stand any quality standards ;-) A little later I got my hands on my father's stereo equipment (SABA receiver and tape deck with a DUAL turntable and some nice Canton speakers). This caused my standards of sound quality to rise. I began buying records and copied them to tape. If I really liked the record it went on a "metal" tape, but usually I spent my money on "CrO2" tapes. Why the hell buy a record and then copy it to tape?? Why not buy the taped recording?? To all those younger folks: because those tapes didn't sound good. Copying the record to high or at least good quality tape would leave you with a much better sound on your way to school while enjoying the luxury of a Sony DD II Walkman. By the end of the eighties CDs made their way into my record collection. (By the way, my first CD was Depeche Mode's "Speak and Spell" album which I already owned as vinyl. I missed the "klick" sounds from my record to which I got used to over the years while listening to this album ;-) ) At first CDs where too expensive for me so I still got records but over time of course I got stuck on CDs - though I still think a good recording and high quality record sounds better than a CD of the same album. Since then quite some time has passed and today's music industry somehow made it's way to digital music downloads and streaming services - which I think is a good thing. However I really dislike treating lossy music formats as replacement for "real" non-lossy recordings. And I don't see the sense in them anymore. Low bitrate mp3 files of course where the only way to get music over the internet through your 56k modem - but nowadays? Really? Don't get me wrong, those codecs are fine while listening to music on your smartphone while you're on the way to work, but as soon you get some descent headphones this sound quality sucks.

As you might have guessed I'm really into music and I'm the proud owner of quite a lot records and CDs. Now and then I need to buy some new shelfs for my growing selection of CDs. Nevertheless or even caused by CDs piling up everywhere I got to appreciate streaming/download services. I started off a couple of years ago with Spotify and lately - not being satisfied with it's sound quality - got to check out others as well.


First let me get a little technical... In order to keep bandwith and file space as small as possible all streaming services make use of codecs. There are two types: lossy and lossless ones. As the name might suggest the lossy ones are able to generate more compact files than the lossless ones. So on the one hand in terms of file space they win. On the other hand the lossless ones sound (a lot) better. Just to give you a hint on saved space: converting an average album on CD to mp3 with 320kb/s only takes about 1/6 of disk space of the original non encoded album. To achieve this the codec will omit parts of the sound information which it thinks is not needed, i.e. frequencies the human ear is not capable of hearing or stereo information of very low frequencies - however the codec has been programmed. There are lots of things those codecs can do to reduce the information and thus the file size. You may imagine that the same album coded as 320kb/s mp3 will even take up less space if encoded with 128kb/s - and sound a lot worse...
Lossless codecs do not omit any information but they just "reorganize" data in better way in order to shrink file size - at least a little. For example, using flac (free lossless audio) codec with default settings will cut the size on an album down by roughly 50%.

Please keep in mind that the sound quality varies quite heavily depending on your equipment and is also subject to your own liking and preferences. The following is what I think and does not necessarily has to be true for you or others as well!

Sound quality

Having that said, let's see how the streaming services were doing for me. I've checked Spotify, Deezer, Tidal, Google Music and Amzon Prime Music. I did not look into Apple Music however. So which codes are they using? I will only mention their respective best quality lossy and - if available - lossless one. (While streaming you may usually choose between three sound quality settings representing different encoding settings.)

Service Codec Best Quality Lossless available (flac)
Spotify ogg 320kb/s no
Google Music mp3 320kb/s no
Deezer mp3 320kb/s yes (*)
Tidal aac 320kb/s yes
Amzon Prime Music mp3 256kb/s no
Apple Music (*) aac 256kb/s no
(*) I did not check this out

ogg like flac is an open source codec and is said to produce slightly better quality than mp3. aac was meant to replace mp3 and might technically produce the "best" lossy outputs.

I used three test conditions:
  • Sony xperia X smartphone with Sennheiser ear buds (not high end) and downloading tracks via smartphone app
  • Sony wireless speaker SRS-Z7 using built in Chromecast for streaming
  • Onkyo mini HiFi system with Google Chromecast Audio attached for streaming and beyerdynamic DT 770 PRO 80 Ohm headphone
I listened to a couple of tracks, i.e. among others Led Zeppelin's "Ramble on (live)", New Order's "Blue Monday" and Human League's "Human". Depending on what your preferences are your result may be completely different of course.
So how how did those services work out in my ears? As I think it's very difficult - at least for me - to put sound quality in words I just go with "++", "+" and "-". Other then "-" is pretty OK for me, but with "-" meaning: I would not like to listen to that for a longer period.

Service Smartphone Wireless Speaker HiFi headphones
Spotify + + -
Google Music ++ ++ +
Deezer ++ ++ +
Tidal ++ ++ + / ++ (lossless)
Amzon Prime Music + - -

As you can see it did not make a big difference if I'd listen on my smartphone or my wireless speaker. The overall sound quality is pretty good with the majority of the streaming services. I felt Spotify sounded a little "flat". Base was pretty good but other then that it sounded a little dull. The lossy formats with Google Music, Deezer and Tidal sounded best to me and on smartphone and wireless speaker I could not hear the difference to Tidal's lossless streaming service. However, it did made a difference as soon as I was listening to the music on a HiFi headphone. If you're into that - and I think that's the way you should really listen to music - definitively go for a lossless stream!
There is a clear "loser" here: Amazon sounded very poorly to me and even on my smartphone I could only hardly give "+". Not sure what the problem is here. I myself have coded mp3 files with 256kb/s which sound way better than Amazon's service. In my ears high frequencies suffered from distortion and the rest was partly overmodulated.

As stated above, this is just my opinion and you might feel differently. The results here are very individual/subjective and depended on my ears, my taste in music and of course my technical equipment.


In order to make use of the streaming services you need to download an app. Some services support a broader selection of operating systems than others or even integrate into other services like Google Assistant or Amazon's Alexa. In my opinion they are all pretty usable with Spotify leading at the top. Just a small overview here (as of March 2018):

App/Service Android  Apple iOS  Chromecast Google Assistant  Amazon Alexa  overall experience/extras
Spotify yes yes yes (via Spotify Connect) yes yes ++
Google Music yesyes yes yes no +
Deezer yes yes yes (little buggy, s. here and here) yes yes +
Tidal yes yes yes no no + / watch videos
Amzon Prime Music yes yes yes (Android) no yes +

The cash...

Well, of course you have to pay for the good stuff. (Spotify and Deezer even offer a free subscription but I don't think it's suitable if you like to listen to music seriously.) Usually it's around 10€/month, 15€/month for a family plan and 20€/month if you'd like to go for HiFi on Deezer or Tidal.

So, happy listening! 😎

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