Learned something new today and it isn't good.
I have been in this crazy hobby for over five decades and thought I knew most of the basic information regarding audio quality.
That was before this morning.
Today I learned about the practise of applying "pre-emphasis" to CDs that was around during the late '70's and early '80's. Apparently this practise was developed as a way of reducing the signal to noise in digital audio. The problem is this was a two-part process and required the CD player to have a "de-emphasis" capability to allow the disk to play properly. Without the application of de-emphasis, cd's would sound "bright".
My question would be, "Does everyone else know about this?"
If you do, "How do you deal with it?"
I still listen to CDs and this is not something I need in my life.
My Lumin D1 has it as well, but it is not an automated function. If you have a CD that requires "de-emphasization" you need to turn the function on in the software. I know it has stopped. My concern is that many of the best quality CDs from that era are pre-emphasized. Specifically many Japanese versions. |
Pre-emphasis is the first part of a noise reduction technique in which a signal's weaker, higher frequencies are boosted before they are transmitted or recorded onto a storage medium. Upon playback, a de-emphasis filter is applied to reverse the process. The result is a higher signal-to-noise ratio (SNR); the original frequencies are restored, but noise that was introduced by the storage medium, transmission equipment, or analog/digital conversions is quieter than it would have been if no filtering had been done. Pre- and de-emphasis can be collectively referred to as just emphasis. Emphasis was sometimes used in digital storage media in the late 1970s through early 1980s, including on a small percentage of audio CDs. Emphasis is akin to Dolby noise reduction for tapes, or the RIAA equalization curve for vinyl records. From what I gather emphasis was implemented to try to improve the sound of the CD players, not the cd's themselves. This is a case where the media was better than the technology to play it. |
I don't know what this has to with the topic. Emphasising was something record engineers did to manipulate the frequency curve to make up for the deficiencies playback equipment half a century ago. Digital sound quality today is for the most part fabulous and all the discussions about it on this site usually involve tweaking sound, not major surgery. |
