Equalizer APO & WASAPI

[daftcombo]

I tried to compare so many times with my foobar2000 global keyboard shortcuts (alt+e for wasapi event and alt+s for shared). I was playing Hi-Res™ song and pressing these hotkeys, trying to hear any difference but honestly I didn't hear any. This is such a dumb feeling when you think that you lose some imaginary details because it's not "bit-perfect",

Me neither.

http://archimago.blogspot.com/2014/06/24-bit-vs-16-bit-audio-test-part-ii.html

 

[AnalogSteph]

No, I mean sox resampler. It upscales audio files? I am not sure if it's really needed. If I understand what it really does of course.

It's a resampler of known-excellent quality that you can set up to output a fixed sample rate, at which point you only have to accommodate that any more.

Question to those who know? What do we actually lose in bit-imperfect reproduction in term of dB or Fr or Timing or ?? What do we lose when reproduction is not bit-perfect ?

Potentially nothing at all, save for a bit of output level perhaps.

We can divide the issue into two fields - bit depth and sample rate.

Even digital level reduction used to be fraught with peril when DACs were 16-bit and software processing was done in 16-bit integer. In the days of 24-bit or even 32-bit DACs and 32-bit or 64-bit floating point processing (Foobar2000's float32 engine used to be a Big Deal - Winamp would use whatever bit depth the audio material was in), it has become a trivial and almost always lossless operation. There are approximately zero recordings with a (white) noise floor lower than 110 dB down, usually around 90 dB is about it. Thus you can afford a level reduction of at least 28 dB, potentially up to 48 dB, while retaining enough noise for a 24-bit DAC to be dithered sufficiently. Add 48 more dB for 32-bit output.
At this point your biggest enemy will be DAC analog noise (a DAC with a 186 dB dynamic range pretty much is a physical impossibility) and potentially low-level nonlinearity... but still, in theory you could reduce the volume of CD material to "you can't even hear it" and still retain full resolution!

Another of these things that used to be fraught with peril is sample rate conversion. Creative Labs EMU10K based soundcards actually were pretty notorious back in the day... actually the built-in resampling wasn't even that terrible (nothing was very good in the consumer space at the time) but it would clip 3 dB below full-scale already, clearly not a good thing at a time when the loudness war had really taken off and reducing digital levels was not unproblematic (see above).
True peak levels exceeding 0 dBFS (as often generated by oldschool brickwall limiters) can still get you in trouble with resamplers to this day... even if just for making an appearance in the digital domain already instead of just being the problem of the DAC and its output stage. That's why ReplayGain scanning with oversampling enabled is a thing.