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Frequency response while streaming stops at 15kHz- did I miss something in the fine print?

I am streaming with Qobuz.  It sounds great playing both CD quality and hi-rez music.  So what's the trouble?  While working to get the bass response in my room just right I found test tracks on Qobuz.  This was very handy as I played 30-60 Hz test tones over and over.  So when I was done with that I streamed a pink noise track and pulled up the FFT analyzer app on my iPhone.  Surprisingly, I see the trace drop straight down to 0 dB above 15 kHz.  I streamed some test tones and confirmed that above 15 kHz nothing is happening at the speakers.  In my old and decrepit state I can no longer hear above 15 kHz so I am relying on the app.  In a panic that something is wrong with my speakers I pull out my vinyl test record.  I have a nice, pretty flat frequency response from 20-20 kHz showing on the FFT app.  I put in a test CD and again show a good 20-20k.  Lastly, I ripped the test CD onto my server and again had a good 20-20k response.  So why did I not know about the limited bandwidth while streaming?  Is it just me?  It is an abrupt cutoff above 15 kHz while streaming.  What's going on?
128x128tonywinga
tonywinga's avatar
tonywinga OP
844 posts
 
This is all not so straight forward.  I streamed music, both 16 bit and 24 bit and I see frequenciies out to 20kHz.  Then I went back to the test disc on Qobuz titled, "Audio Line-up Test Tones".  Some tracks cut off at 15kHz such as the test tones at specific frequencies, frequency sweeps  and some pink noise tracks but some tracks go out to 20 kHz such as the white noise tracks and other pink noise tracks at -10dB for example.  Really strange is that the specific 18 kHz test tone track shows no response for me while my own test CD shows a response at that frequency just fine.
My conclusion is Qobuz is streaming the full bandwidth and I happened to stumble across a test disc in their library with some foibles.  
tonywinga's avatar
tonywinga OP
844 posts
 
As it turns out it is not me and it is not Qobuz.  It is the Test CD in their library.  The question is why.  Why do some tracks on the CD cutoff at 15 kHz but other tracks do not?  And why did this happen on a test CD of all things?
vanson1
126 posts
 
Try a signal generator and see what your upper limit of hearing is. 

Bet you can't hear 15k at all. 

Moot point. 
discopants
149 posts
 
I think it’s an apple thing OP. If you stream from an apple device hi rez stuff gets compressed by apple. Heard this from some folks

Check it’s not a app setting though

I have lots of apple devices but I use a Samsung phone and bubble upnp to stream qobuz. 
discopants
149 posts
 
P.s compressed music can sound mighty good indeed if it's been compressed thoughtfully from red book or high res.

You can lose very little quality, especially with a DAC that upsamples well.

However if the recording is poor and compressed from the get go you will notice.

Recording quality is orders of magnitude more important than digital compression.
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