Room correction with convolution per sample rate

[digimuse]

Alan, thanks for the correction. My introduction to convolution was the post (convolution with acourate fir filter). An error message would be helpful if stream.transcode is blank and stream.options has convOut ...

From my earlier tests:

Test 1: bit perfect
source: 16/44.1 kHz
stream.options: <blank>
stream.transcode: <blank>
SPL: 80 dB

Test 3: apply 44.1 kHz convolution filter (but missing stream.transcode)
source: 16/44.1 kHz
stream.options: convOut=-i /mnt/disk1/share/MinimServer/convolution/Cor1S44.wav -lavfi afir
stream.transcode: <blank>
SPL: 80 dB

Now I realize that this should do nothing, because of the blank stream.transcode

I ran a few additional tests:

Test 6: convert FLAC to WAV (no sample rate change)
source: 16/44.1 kHz
stream.options: <blank>
stream.transcode: flac:wav;
SPL: 80 dB

Unchanged SPL is ok, as only transcoding FLAC to WAV.

Test 3-1: convert FLAC to WAV and apply 44.1 kHz convolution filter
source: 16/44.1 kHz
stream.options: convOut=-i /mnt/disk1/share/MinimServer/convolution/Cor1S44.wav -lavfi afir
stream.transcode: flac:wav;
SPL: 60 dB

Something wrong here with 20 dB volume reduction.

My only valid tests of convolution are: Test 3-1, and from my previous email Test4 and Test 5.

All of these tests have a roughly 20 dB reduction in volume (for me), which is not right.

Simon repeated Tests 3 and only got a reduction of 3.5 dB, which is very different from the 20 dB reduction I got.

My setup must be different.

I installed ffmpeg using the instructions at:
Installing MinimServer on a Melco N1

If you have installed MinimStreamer and you want to use FFmpeg as a stream converter, you can copy an ffmpeg static binary into the ahare/MinimServer/opt/bin folder and restart MinimServer by powering the N1 off and on. [NEW] You can download a suitable ffmpeg static binary from this page. For the Melco N1, you need the armhf build.

I'm also using JRiver as a control point, which should not be a problem (JRiver is not doing any processing - it's just instructing MinimServer running on Melco to send audio to my DAC directly over the network).

MinimServer is using ffmpeg for convolution, but JRiver is using its own engine(Native JRiver 64bit fp convolution ...), which works for me (when I use JRiver as the server).