i'm having a problem with digital brick wall mastering


sam here and my problem is simple? all the digital albums that i download have a lot of brick wall mastering applied and it make the audio sound distorted and lifeless? i was able to find an allpass filter that removed the brick wall mastering however for some unknown reason after the brick wall mastering was removed the dynamic range is now too high on average 8db increase and i have to reduce the digital volume to prevent clipping. also now the audio sounds to analog like with all the digital sound gone? it’s like vintage vinyl on steroids? is there a filter that can remove only half of the brick wall mastering. all my digital audio now sounds like a live studio performance?
guitarsam
Hey Sam,

I’m not sure what you mean about brick wall mastering. There’s no way to restore data that has been removed, but ...there is upsampling and oversampling, as well as different types of filters used by the DACs, some with slower rolloff. Maybe this is what you mean by brick wall?

If you used some sort of digital conversion like ffmpeg, or sox (on Linux) to upsample you may have gotten some level shifting as a result.

I encourage you to learn to use either of them, they re like swiss army knives for altering digital music files.

Best,

E



i'm talking about the loudness wars and audio distortion and the audio waveform looks like a 2 x 4 and then after using the iir allpass filter with foobar2000 set at default with volume increase at zero so all i'm doing is running the audio through the filter without changing the settings and now instead of the waveform looking like a 2 x 4 it has large peaks and all the distortion is gone?
I'm not sure what you mean by "allpass filter".  The function of "allpass filter" is to delay phase without affecting amplitude (flat frequency response).  Clipping might be caused by intersample peaks/overs. They happen when filtering of the DAC's output staircase waveform produces amplitude slightly higher than highest unfiltered step.  Recording engineers should leave some headroom for that, but it is usually less than 1dB.  It is possible that with loudness wars they failed to do it.  Still, I doubt that it would be so audible on many records.  My Benchmark DAC3 processes data to provide extra 3dB of headroom for intersample overs, but 3dB is probably overkill.  You can find info here:   https://benchmarkmedia.com/blogs/application_notes/intersample-overs-in-cd-recordings
o.k i got an answer that sounds logical to me however that doesn't mean it is logical? i was told that because digital audio is bit perfect when i run the audio through the allpass filter even though the volume level is set to zero so no processing is taking place just the fact that i'm running the audio through the filter will create maybe a 1ms delay so the audio no longer lines up perfectly with the original waveform so a new wave form is created as if the brick wall mastering had never been applied.this would explain why all the distortion i was hearing is gone and the increase in dynamic range with a more open sound stage.so as a test i ran metallica death magnetic digital album which has a dynamic range of ( 3 ) through the same allpass filter and the average dynamic range after processing is (15) so i have to decrease the volume so the audio doesn't clip.
Delay should not make any difference unless filter does something else to reduce peaks.  At this point we don't know what this filter does, but if it works then use it.

yes but when the audio sounds very distorted you know it's been compressed
It doesn't have to be compressed to sound distorted.  Brick wall filtering might affect sound negatively but not by compressing the sound.