HB DAC+pro, playback samplerate really 44100?

[uwedamm]

Hallo together,

I got a strange effect when measuring my hifiberry dac+ pro output using an M-AUDIO192 soundcard.
I play a 1kHz sin-wave (.wav file 44100 sps, 16bps)
When I measure using 44100 sps, and look at the FFT, the peak is quit wide.
When I am using 192000 sps, the peak is much more narrow.
Maybe my matlab mathematics are not perfect, therefor I would like to be sure, that the runeaudio does not do any resampling (to 48000?)
How can I check that?
cat /proc/asound/card1/pcm0p/sub0/hw_params
shows:
> access: RW_INTERLEAVED
> format: S24_LE
> subformat: STD
> channels: 2
> rate: 44100 (352800/8)
> period_size: 4410
> buffer_size: 22050
Is the "rate" the effective rate, which is sent to the hifi-berry?
In that case I have to recheck my matlab script more deep

thank you for any feedback and best regards
Uwe

[hondagx35]

Hi Uwe,

Is the "rate" the effective rate, which is sent to the hifi-berry?

Yes, it is.

Frank

[uwedamm]

Hello Frank,

thank you really much for that fast reply.
I have got no idea how many hours per day you spent to support us for all these "stupid" questions

I will try to fix my measurement/mathematics, hopefully getting some more experience in FFT ... (I think a suitable filter function like blackman harris ... kaiser ... might help, but I expected, that the most narrow peaks should be possible using boxcar )

Best regards and again thank you for the new runeaudio (RuneAudio_rpi2_rp3_0.4-beta_20170229_2GB.img.gz until now works perfect for me!).

Uwe