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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
sandstone
358 posts
 
Hi Tony,
Interesting question. (and great system, btw!)  I'm running Tidal on my setup but have a trial for QoBuz and would like to install and test this issue.  Do you recommend any particular FFT analyzer app for iPhone?
Howard

tonywinga's avatar
tonywinga OP
844 posts
 
I use the app called n-track tuner on my iPhone. My vinyl test record is Stereo Review SRT14 from the 1980s. It’s hard to use for wow and flutter measurements because the hole is off center by almost the full tolerance- or maybe that’s they way they wanted it. I am using a RS9 music server running Roon.
audiom3
153 posts
 
@tonywinga I’m not sure what’s going on then. I pulled out a spectrometer app just for kicks and I get plenty of action even over 20kHz+ (at my listening position) with Roon+Tidal in my setup. All fiber LAN. Running a mini PC feeding a PS Audio DS DAC Bridge II to Ayre KX/VX-5 Twenty pre and power amps powering Legacy Focus SE speakers. /shrug, all good here.
mapman's avatar
mapman
22,408 posts
 
My guess would be something in your streaming setup is filtering above that frequency.   Could  be a setting somewhere.  
ghdprentice
7,255 posts
 
While you may not hear above 15khz, the overall effect on the music can be significant. After decades of working on my system, and own Heils and other planar speakers I realized that the real high frequency has a profound impact on the overall sound quality. I have not fiddled with measuring up that high. But a cut off sounds artificial. I’ll be interested to hear more about this.
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