The frequency response you measured looks very good indeed. Are you sure the playback sampling rate was 192kHz ? The sweep frequency goes up to 96kHz but "only" 40-something comes out. This could indicate resampling to 96kHz.

What are you going to be playing these through? Headphones? IEMs? I've never seen any IEMs that go above 20KHz, I'm sure there are some but even very good ones don't go higher than this.

Quote from: devoidzer0 on 2014-05-16 03:24:21

Just so I don't leave anyone out, here is the frequency graph from Kees de Visser's 0-48 kHz sine wave sweep, as played back from my phone (thanks!):

It's a 0-96kHz sweep actually. When uploading the testfile I typed that wrong. Moderator Kohlrabi has corrected that, thanks!.
The frequency response you measured looks very good indeed. Are you sure the playback sampling rate was 192kHz ? The sweep frequency goes up to 96kHz but "only" 40-something comes out. This could indicate resampling to 96kHz. That's probably not enough reason to sell your S5 and buy a Pono though

I'll be playing them through relatively cheap earbuds, mostly.  Guess that doesn't help the case for 96k. 

Lossless in general, and (IIRC) flac in particular, just isn't efficient for higher bitdepths - and, to a lesser extent, higher sample rates.

I'm not talking about audibility, or anything like that. What I mean is that the extra LSBs are effectively almost all noise, and hence unpredictable, and hence incompressible. For PCM, the raw datarate increases by 50% from 16-bits to 24-bits. For non-loudness war recordings, the increase in FLAC bitrate can be much greater.

The increased sampling rate isn't so much of a killer, especially on the many recordings where essentially "there's nothing extra up there" in the higher frequencies. However, I have a recollection (correct me if I'm wrong) that FLAC's predictors (and maybe its default black size) don't work as well at 192kHz as at 44.1kHz. Even if there's no extra real information (i.e. you simply upsample 44.1 > 192 essentially perfectly), the bitrate increases.


If you want measurable perfection beyond the bounds of the best human hearing while taming bitrates slightly, something like 20/96 with a gentle low pass filter starting at about 25kHz is a good choice. 24/96 or 24/48 run through lossyWAV with conservative settings (including, for examples, always keeping at least 16-bits intact) is another option. A higher bitdepth gives you a wider dynamic range (which you don't need) and the ability to turn the volume up during fades and reverb tails without hearing dither noise; a higher sample rate gives you a wider frequency response (which you don't need) and the ability to play back inaudible test signals instact and without intermodulation due to slow roll off DAC filters. It's things like this that are really important when you're listening to music on the move

Higher bitdepth and sample rate don't make things within the normal audible frequency and dynamic range more accurate. Certain people claim they do, but that's because they don't understand digital audio and, frankly, like to imagine things - or are trying to sell you something. People who believe this stuff often take great care with their recordings, and so they sound very good. The same recordings still sound very good converted to 16/44.1.

Cheers,
David.

Quote from: Kees de Visser on 2014-05-16 10:01:46

The frequency response you measured looks very good indeed. Are you sure the playback sampling rate was 192kHz ? The sweep frequency goes up to 96kHz but "only" 40-something comes out. This could indicate resampling to 96kHz.

OP's sampling rate on the recording side is known to be @ 96.

Oh yeah, you're right!  I totally forgot that the Mac mini's sound card is limited to 96k.  That would explain why the recording frequencies were cut off for the 96k tone test.  So, the phone can theoretically play back 192, but I have no way of verifying this because I don't have a sound card that supports that high of a bitrate.

Quote from: Kees de Visser on 2014-05-16 10:01:46

The frequency response you measured looks very good indeed. Are you sure the playback sampling rate was 192kHz ? The sweep frequency goes up to 96kHz but "only" 40-something comes out. This could indicate resampling to 96kHz.

OP's sampling rate on the recording side is known to be @ 96.

Thank you, that's very good info.  I guess the sensible thing to do is just do my own ABX testing and see if I can even tell the difference before devoting gigabytes to high res audio, which I haven't really done in a scientific way.  I know 24/192 is complete overkill, but I'll have to do my own tests with 24/96.  I don't really have a desire to do my own manual tweaking with going to 20/96 and using filters, since there are libraries of music already available in 24/96 (from HD Tracks, for example) and that is a pretty standard format , but I appreciate the suggestion.

Quote from: devoidzer0 on 2014-05-16 15:34:10

I'll be playing them through relatively cheap earbuds, mostly.  Guess that doesn't help the case for 96k. 

So why do you want lossless 24/192 files again?  I have good IEMs and listen to MP3s.

If you want to get full advantage of 24/192

KitKat documentation clearly states that system provides downsampling without dithering. Regarding testing the files, it is wasting time. First at all you can't hear this frequency so you can't test using ears. Even if you get oscilloscope and connect to Samsung phone jack, you can still see nothing, just because Samsung audio analog track is limited to 20KHz.

Even if you get oscilloscope and connect to Samsung phone jack, you can still see nothing, just because Samsung audio analog track is limited to 20KHz.