Does exporting even in lossless formats lose fidelity?

I am exporting some mixes, master bus, same session rate, same bit rate, lossless FLAC. When played back by an Audio player such as VLC, it seems to lose a bit of fidelity. Not much, I’d even say acceptable, but definitely a loss.

When I A/B playback the lossless FLAC next to the Ardour Master bus, there is a definite perceivable difference. The Ardour Master bus output seems, i don’t know, just brighter and maybe a tad louder or something.

Is this a normal expectation for exported audio? I assumed a lossless session rate master bus export file would be a replica of what I am hearing from the Master bus output directly in Ardour.

Our ears are easily fooled by many things, notably by volume changes (louder always sounds better) which is why level matching is critical for A/B tests. I’d reccommend you export a WAV file and play it back in your same player and see if you notice any difference from the flac.

I tried that, and there was no noticeable difference between a wav and flac. I even down-sampled the wav to 44.1/16bit from 96/24bit and could not perceive a difference.

Export to a 24 bit flac file and don’t use sample rate conversion (select “session rate” in the Ardour export preset). Flac is a lossless compressor and when the file is played back the data uncompresses to exactly what Ardour exported, no quality loss there.

If you export to a 16 bit file then you probably lose a bit of fidelity and add a little bit noise as Ardour uses 32 bit audio processing internally. The same goes if you export to a sample rate differing from your session sample rate.

Also play the file with some other player than vlc to see if the problem lies in playback. Vlc has post processing, check that you don’t have the EQ on.

I’ve seen a “placebo effect” myself when I was listening to audio example files. If I expected to hear a higher quality file, I quite clearly heard that the quality was higher only to learn later that the file was not the high quality one :slight_smile:

Get someone to play Ardour and the flac file to you when you don’t know which one is playing and see if you can still hear the difference.

Forgot to say: No there should be no difference in what you hear while Ardour plays back and the exported file.

If there still a difference in quality you could rule out misbehaving plugins by routing Ardour output to a stereo track and recording it in realtime. Then export just the recorded track.

“Export to a 24 bit flac file and don’t use sample rate conversion”, that is how my FLAC files are exported. The only time I converted session rate was with the wav file.

Maybe I should import that FLAC into my song, then A/B it with the master track all within Ardour? That could eliminate any differences between Ardour and VLC. Should there be any difference between the master bus output of Ardour and the playback of something like VLC?

As for your workaround, so take the outputs of Master L/R into 2 separate new tracks, record enable those tracks, then play/record the song into those tracks? Then export the tracks instead of the master bus?

Yes (for the routing and export).

I don’t expect there to be any difference in sound if the audio goes through the master bus the second time or not.

If this is the win10 machine you had trouble with, then maybe you should compare the sound on your Mac also.

If you import the file back into Ardour, then you could reverse the polarity of the track that has the imported file and play back the original session audio with the inverted one. This should cancel out all audio and you should hear nothing. If you hear something that is the difference in the signal between the exported file and Ardour playback. Note that volume and the place in time for the imported file must exactly match the original audio in the session for this to work. Even a slight misalignment (1 sample) will make this fail.

I’ve used Ardour (on Linux) for a couple of years and never noticed any difference in the playback and exported audio quality.

I think I figured this out. VLC was at 80% volume, Ardour master bus at 100%. I did mention I am still a novice at this right? Thanks for everyone’s insight.

And if you want to understand why you did not hear any difference between 44.1/16bit and 96/24bit, you reccomend reading this:

And watch this.