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
It's not the limitation of iPhone microphone it's a limitation of the way apple wireless devices stream. 

The stream actually passes through the phone and apple compressed it. 
Well clearly the issue was never qobuz service as best I could tell and now we know it was a particular recording in this case a test recording. Not uncommon for individual recordings to have severe limitations that may or may not matter. Case solved.
@tonywinga You should be a little more careful before posting. Everyone in a tizzy over miscalculation, this is exactly how misinformation is spread.

I applaud you for quickly acknowledging your mistake.

I will agree with Nonoise that optimized streaming will be great sounding, but not inexpensive or simple to accomplish.
p05129, go back and read what I wrote. There's nothing between the lines that said I stream anything. There's that qualifying phrase,
The closest I've come to it is with using some nice active speakers with a  built in DAC taking it directly via USB from my Mac. I only listen do casual listening and it's really not bad, either with my stored music or with internet FM listening. But it pales compared to my CD based rig and I'm not about to dump lots of money into something that's changing and improving as I write this. The process would drive me crazier than I am now. 😀
Like others here who've already pointed out, it's really expensive to have  a great sounding streaming set up. Lots of online reviewers have been saying that for a long time now.

All the best,
Nonoise

I think markc nailed it: "I suspect the reason was not my test tones or my system, but a limitation of the iPhone microphone." 
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.
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. 
Try a signal generator and see what your upper limit of hearing is. 

Bet you can't hear 15k at all. 

Moot point. 
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?
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.  
15khz! That’s crazy! Now, if you don’t mind, I’m gonna listen to my records. Good stuff…

Nonoise - you use a mediocre system for your streaming test (speakers with a built in dac and using usb probably using iTunes too) and you think this is a good representation of a good streaming system? I’ll take streaming/playing ripped songs over using a CD player or vinyl.
The only thing I find related to frequency response is a low pass filter which is set at 30 kHz
Depends what order it is and how many db down at 30k it already is.

Cheers George
I checked my Roon settings.  The only thing I find related to frequency response is a low pass filter which is set at 30 kHz.  I don't think that is the issue.  The speakers go the full 20 kHz when playing back a FLAC version of my CD test disk loaded on the music server HDD.  The iPhone mic picks up 20 kHz no problem as I saw both from the CD test disc and my vinyl test record.
Played back from my PC and the response seemed to stop at 15 to 16KHz. I suspect the reason was not my test tones or my system, but a limitation of the iPhone microphone.
I suspect it more that they save 20% of streaming/download space by not letting it go out to 20k regardless if there's info on it or not.

Cheers George
All you need to know about quality streaming. Courtesy of Bryston. Beware; Have a fat wallet if you want the best in the industry. Between approximately $4000 and $12,000 to stream and play your high resolution music at its best. https://bryston.com/digital-audio/
I did the same experiment but used test tones played back from my PC and the response seemed to stop at 15 to 16KHz.  I suspect the reason was not my test tones or my system, but a limitation of the iPhone microphone. 
Allan Silverman one of the recording industries best.
https://youtu.be/EiRMYoqU3ys?t=575

So Digital is a quest for loudness. Utter garbage. 

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.
My guess would be something in your streaming setup is filtering above that frequency.   Could  be a setting somewhere.  
@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.
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.
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




Because nothing is compressed in life’s sounds, why do it to our music!!
Is a live artist you sit in front of compressed NO!
(my theory is for the companies to save space on streaming/downloads)

Also leaving it uncompressed gives the music a chance to breath, (you can’t have loud bits if there are no quiet bits), also gives the ears/brain a chance to breath as well, instead of everything being the same level and sounding confused.

Cheers George
Frequency response while streaming stops at 15kHz- did I miss something in the fine print?
If you think that’s bad being band width limited, look at the dynamic range of it, as they use the later re-issues not the originals the way the band/s wanted it to be heard.
Then purchase CD’s that have not been compressed (usually 1st issue), search here for those.
https://dr.loudness-war.info/album/list/year?artist=Traveling+Wilburys
Most later re-issues have been compressed.
Except some, but they command big prices $80 ebay used as this 2019 uncompressed Japanese one at the bottom.
https://dr.loudness-war.info/album/list/year?artist=elton+john&album=Madman+Across+The+Water
Cheers George
tonywinga
It is an abrupt cutoff above 15 kHz while streaming.  What's going  on?
What kind of hardware and software are you using?

Is it an issue? Show your last hearing test.
I’m my day hifi was defined as 50-15000.
Do you really need more than you can use.
Makes for good troll food though.
You get what you pay for with FM radio.
I sold my tuner years ago for what it was worth, next to nothing.
Which vinyl test record do you own that's flat out to 20kHz?  I have yet to find one.  I have three and all drop fairly sharply at around the 16-18kHz range.

Also, I preferred the sound of Tidal when I compared it to Qobuz earlier this year.  Tidal had more treble extension to my ears and Qobuz had more bass and midrange warmth.  We are talking about the margin of splitting hairs here though. 
I don't doubt you are reading a 15kHz cutoff but I am pretty positive I am hearing over 15kHz with Roon/Tidal in my setup.  Are you sure your streamed audio isn't being transcoded somewhere in your audio chain?  Not sure what frequency response mp3 has because I never listen to them.
Is this another way of streaming FM? It's limited to 15Khz as well but with streaming, you have more bandwidth limited music at your fingertips. At least FM is free.

Sorry for the snark but that's how I've always felt about streaming. For those who like it, more power to ya. When they finally figure out universal standards and simplify the process, then maybe I'll try it all out.

The closest I've come to it is with using some nice active speakers with a  built in DAC taking it directly via USB from my Mac. I only listen do casual listening and it's really not bad, either with my stored music or with internet FM listening. But it pales compared to my CD based rig and I'm not about to dump lots of money into something that's changing and improving as I write this. The process would drive me crazier than I am now. 😀

All the best,
Nonoise