Unless I missed it, there was no device make/model listed. There is mention of a Samsung USB-C "dongle" and that it is 1.0Vrms capable but limited to 0.2Vrms typically. Seems this could have limited audio quality and not fit into the true "hi-res" category. I'm doubting the 192kHz capability claim as well for the same reason. But obviously this means the phone DAC's are bypassed, and the signal is being converted to analog on the way to the outboard device measuring the response.blaubär wrote: ↑Tue Aug 15, 2023 6:57 pmOkay, so they played a sweep ( constantly rising tone ) on a smartphone, with several equalizers set to a common preset, fed the smartphone's analog output ( or the digital one ? ) into a "Creative GC7" ( an external DAC ? ) and recorded it there, then imported the data into "REW / Room EQ Wizard" ( audio software ). As reference the REW calculated the output from a flat input and the eq preset. Did I get that right ?
The test signal was generated from the test software, 10Hz-22kHz at 48kHz (16 or 24 bit?). So this limits the frequency response testing already.
The tests for both Wavelet and Poweramp were run at 44.1kHz and 192kHz. Likely this was influenced by the 48kHz sample rate test tone that was generated and possibly had some effect on the stepping results in those measured curves. The additional results measured afterwards with Neutron may have been coloured by measurements run at different times. And certainly if 64-bit processing was enabled, that too could account for the extended high frequency improvement I see runnig out to 20kHz and beyond.
The curves themselves are all very close across most of the frequency range. Seems there is a small level difference for each, that could be simply caused by unmatched preamp levels, Replaygain, etc. in the software of each app. If these were dynamically matched (adjusted to overlay each other without the volume offsets), it would be more clear to see where the true response differences stand out.
This was not the most scientific or controlled test scenario. Certainly the results and the interpretations were subjective. Just as much as my personal comments are here. Without having all of the other subsets of data and the options that were enabled or disabled in each of the tested apps, there is no way to fairly assess where these identified gaps have come from.