Why computer audio often times sounds harsh even on high end sound cards & DAC's

[germanium]

It's a simple truth that many recordings sound harsh on computer based playback systems, especially when copied from or played back from CD's but not from high resolution sources.
 
The problem arises from the fact that many CD's were mastered with a pre-emphasis. There is a 10db boost @10KHZ on these recordings. It is not the fault of the sound card or DAC that it sounds harsh. It is the pre-emphasis & the fact that computers generally do not sense & correct for this pre-emphasis. Compound this with the fact that many people here insist on running in some sort of bit-perfect mode & then wonder why it sounds bad. Note it will sound great on recordings without pre-emphasis but horrible otherwise.
 
I have continued using the standard windows media player & yes I tried others but sensed no real advantage, not only that but most other players would not display much of the music information correctly as well as the bog standard media player in windows, a huge disappointment. I also tried both WASAPI & ASIO with those players to no real advantage.
 
The message here is we need to give up bit-perfect playback in order to have truly correct balanced playback on many CD based recordings.
 
I have been using the Windows Media Player EQ function to correct this pre-emphasis with great success. The settings that I use are all flat up until 2KHz then at 4KHz I cut the output by 3db & 8KHz by 9db then 16KHz by 10db. this pretty accurately corrects the pre-emphasis & the music still remain lively but with out the harshness on  pre-emphasized recordings. One way you can tell if it has been pre-emphasized is the upper range of piano recordings will sound unusually bright & tinkly. This disappears with my correction & the piano then sounds natural. Cymbals will also be harsh without the correction in most cases where there is pre-emphasis.
 
I hope this helps many of you fellow audio enthusiasts.
 

 
 
Ron Brandt

 

[RRod]

 
I have been using the Windows Media Player EQ function to correct this pre-emphasis with great success. The settings that I use are all flat up until 2KHz then at 4KHz I cut the output by 3db & 8KHz by 9db then 16KHz by 10db. this pretty accurately corrects the pre-emphasis & the music still remain lively but with out the harshness on  pre-emphasized recordings. One way you can tell if it has been pre-emphasized is the upper range of piano recordings will sound unusually bright & tinkly. This disappears with my correction & the piano then sounds natural. Cymbals will also be harsh without the correction in most cases where there is pre-emphasis.
 

 
SoX has a filter to remove pre-emphasis, so if you know the CD has is (it think cdparanoia can detect it), then you can convert as easily as:
sox cdda.wav out.wav deemph

 

[germanium]

   
SoX has a filter to remove pre-emphasis, so if you know the CD has is (it think cdparanoia can detect it), then you can convert as easily as:
sox cdda.wav out.wav deemph

Thanks for that info however I'm no good at command line type stuff & I imagine that a lot of people here aren't though it is still good you posted it for those that are good at that kind of thing. I looked up cdparanoia & could not find anything in the documentation about detecting the pre-emphasis flag.

 

[RRod]

 
Thanks for that info however I'm no good at command line type stuff & I imagine that a lot of people here aren't though it is still good you posted it for those that are good at that kind of thing. I looked up cdparanoia & could not find anything in the documentation about detecting the pre-emphasis flag.

 
Command-line will always be less popular than the GUI, but still good to have tricks up one's sleeve. As with much free software, the documentation can leave one wanting a bit:
cdparanoia -Q
should print out the CD table of contents, including a column called "pre" that indicates tracks having pre-emphasis.

 

[gevorg]

The problem arises from the fact that many CD's were mastered with a pre-emphasis.

Actually, pre-emphasis was used in the early era of CDs in 1980s, but today and in the last two decades or so, most CDs do not have any emphasis. Search online can reveal some lists of CDs that have pre-emphasis:

http://www.studio-nibble.com/cd/index.php?title=Pre-emphasis_(release_list)

 

[germanium]

Actually, pre-emphasis was used in the early era of CDs in 1980s, but today and in the last two decades or so, most CDs do not have any emphasis. Search online can reveal some lists of CDs that have pre-emphasis:

http://www.studio-nibble.com/cd/index.php?title=Pre-emphasis_(release_list)

I have some that were released in the 90's that have pre-emphasis so it didn't just suddenly end with the 80's. Ronan Hardiman's Anthem album from 2000 appears to have pre-emphasis at least judging by the sound, much improved with my correction. Even with the correction it still is somewhat bright to my ears but at least seems to be in keeping with the type of music & is at least is now listenable. I have many recordings without pre-emphasis that sound absolutely phenomenal on my system so it's not my system that is the problem. Virtually all 24 bit 96KHz recordings sound phenomenal. They do not have pre-emphasis. 

 

[jiiteepee]

There's a CD de-emphasis plug-in for foobar2k (IIRC, enabled automatically through cue info) and even couple of my Parametric EQ GUI's for EqualizerAPO software supports CD de-emphasis as well (based on SoX code) ... here are the few lines needed in EqualizerAPO config.txt (or in include file).
 
#ISO908 (CD) de-emphasis filter
Channel: All
Preamp: 0.00 dB
Filter: ON IIR Order 2 Coefficients -0.08782333709141920 0.45995451989513100 0.0 1.0 -0.62786881719628800 0.0
 
 

 

[germanium]

  There's a CD de-emphasis plug-in for foobar2k (IIRC, enabled automatically through cue info) and even couple of my Parametric EQ GUI's for EqualizerAPO software supports CD de-emphasis as well (based on SoX code) ... here are the few lines needed in EqualizerAPO config.txt (or in include file).
 
#ISO908 (CD) de-emphasis filter
Channel: All
Preamp: 0.00 dB
Filter: ON IIR Order 2 Coefficients -0.08782333709141920 0.45995451989513100 0.0 1.0 -0.62786881719628800 0.0
 
 

 
That's cool Hopefully that will help most people who work mostly through GUI.

 

[jiiteepee]

   
That's cool Hopefully that will help most people who work mostly through GUI.

Hmm... code lines is for those not using GUI. GUI has a menu selection for to select this feature ON/OFF (software generates the same code lines when feature is enabled).

 

[gevorg]

Actually, pre-emphasis was used in the early era of CDs in 1980s, but today and in the last two decades or so, most CDs do not have any emphasis. Search online can reveal some lists of CDs that have pre-emphasis:

http://www.studio-nibble.com/cd/index.php?title=Pre-emphasis_(release_list)

I have some that were released in the 90's that have pre-emphasis so it didn't just suddenly end with the 80's. Ronan Hardiman's Anthem album from 2000 appears to have pre-emphasis at least judging by the sound, much improved with my correction. Even with the correction it still is somewhat bright to my ears but at least seems to be in keeping with the type of music & is at least is now listenable. I have many recordings without pre-emphasis that sound absolutely phenomenal on my system so it's not my system that is the problem. Virtually all 24 bit 96KHz recordings sound phenomenal. They do not have pre-emphasis. 

Sure, there might even be one from 2000s, but these are still very small in numbers. Most CDs do not have pre-emphasis, hence a properly setup computer/network audio is no worse than a disk transport (if not better).

Some early digital recording & playback equipment, including CD players, used 14-bit converters, even though they were dealing with 16-bit audio. The resulting noise introduced by these converters and filters could be made relatively quiet by using pre-emphasis: boosting the signal (especially the higher frequencies) in the recording before it was put onto CD, and embedding flags in the disc's subcode to tell a CD player to apply de-emphasis on playback. By the late 1980s, pre-emphasis stopped being used because reliable 16-bit DACs with oversampling and other technologies minimized the conversion & filtering noise without the need for pre-processing the recording. Most major-label CDs with pre-emphasis were manufactured in Japan in the early and mid-1980s. Relatively recent forum posts indicate that pre-emphasis is still used on newly manufactured CDs by some indie labels, mainly for classical titles.

 

[germanium]

Ronan Hardiman's Anthem album was released on Decca which is not an indie label or a recent label. They are a very old & respected label from England. I will admit however that much of my music is older as well as being released on labels that pressed their CD's in Japan where many of those earlier CD's had pre-emphasis. Also this album is electronica type music with somewhat limited dynamic range so that pre-emphasis would not actually be needed on any equipment.
 
By the way virtually all early Japanese CD players came with true 16 bit DAC's but no oversampling, linearity on many of them though was actually quite poor even after they introduced over sampling on their CD players with the old ladder type DAC's. By late 80's some Japanese players had oversampling as well. It was the European CD players that came with 14 bit DAC's but those for the most part had oversampling. Anyone that used the early Philips chips such as Magnavox were 14 bit oversampled DAC's. In the 90's many manufacturers started to use highly oversampled 1 bit converters which actually improved low level linearity by moving from a relatively low frequency amplitude stair stepped based system to a high frequency time based method of obtaining linearity accuracy. The first could be compared to AM radio & the later ones to an FM radio.
 
Some early Denon recordings were 13 or 14 bit, can't remember which, but those recordings predated the release of CD's though were used on some early CD's. They were used originally to record LP's then later released on CD.
 
Virtually all the sonic foibles of the digital system have been solved over the years, now it is problems at the recording & mastering stages that have been wrecked not by the equipment but by the producers trying to cram as much loudness as possible into the recordings that couldn't be done before due to the limitations of the LP medium.