CD Audio Pre-Emphasis | What is It and Why Should You Care?

[@purplesabbath9057]

Early CD players often had 14 bit DACs. Since CDs are 16 bit, early CDs were mastered with pre-emphasis to compensate for the extra noise that would have been generated by a 14 bit DAC.

[@johnm2012]

Why would a 14-bit DAC generate extra noise? The two least significant bits can simply be ignored, resulting in less precision but also less noise.

[@purplesabbath9057]

@@johnm2012 Good question, but I don't have the answer. I just know that's the supposed reason why many early CDs have pre-emphasis.

[@thetubesrock]

Thanks for the interesting video Joe. You learn something new every day. 😁

[@EzeeLinux]

Never heard that before. 14 bit DACS aren't necessarily noisy but you do lose a bit of resolution. pre-emphasis would help preserve fine detail in the highs. There's very little info written about the reasoning behind adding pre-emphasis to the CD standard so resolution on under-performing hardware could have been a deciding factor. :)

[@AC9BXEric]

​This is about wave shaping. Changing bit depth would change dynamic range. It wouldn't affect frequency range. Preemphasis for very early digital recording might be helpful because the D to A methods then were not the best. Filtering was used for wave shaping (it still is but it's different) & it would roll off the higher frequencies. It has nothing to do with resolution.

[@kychemclass5850]

I find your video narration and content to be excellent! I'll selfishly ask you to keep making them :)

[@basspig]

I learned about preemphasis on CDs when the day emphasis filter started to become intermittent on my Technics CD player that I bought in 1983. CDs started to sound really harsh and ultra bright sounding and I sometimes wonder if this is the reason why people hate the sound of CDs and prefer vinyl.

[@stevegerst5229]

Thanks Joe. I always learn interesting info on your channel!

[@timothystockman7533]

I engineered a disc with emphasis, "Twopenny Hangover". It was mixed onto a Sony PCM701ES at 44.056 kHz, which did pre-emphasis in analog. At Sony DADC (Terre Haute), they played it back on a Sony PCM601ES through a digital sample rate converter (44.056 to 44.1) to a PCM1630, but they retained the emphasis all the way through to the disc.

[@ron6607]

The ripped version of my "Marillion - Real to Reel" CD sounded very bright. Now I know why. Thanks.

[@SlowMenThinking]

This brings back memory's I remember the oversampling war and I remember when it seemed to stop. Back then I was a Yamaha Guy the last two CD players I had from them, it had a switch that bypassed the analogue filter from the end of the signal chain supposedly for some clarity. In the early 2000's I got my last CD player a Rotel unit this one made some cds that sounded muddy just play nice and clearly, I never knew what its DAC topology was it just worked I never liked the early 1 bit stuff as it was cheap, when I got into CD ripping around 2005 that same disk sounded yuck I had to wait till the DAC's in my computer playback and external DAC's got good. My CD collection dates from around 1987~ish I was still buying LP's back then I still have them. To the best of my knowledge I never ran into the Pre-Emphasis on disks though I do know about from the blurb of the days... I whish I had that Rotel CD player, as using a Blue Ray player just aint the same experience.

[@musiqtee]

Ok, I’m the 2nd category - and well done, insightful and informative! 🎶👍 I started joining in on CD-mastering in May ‘88, when the process was «AAD» (silly marketing jippo, but real nonetheless). I then started to master for CD myself, around 2011 (along with vinyl and of course for streaming). Yes, the pre-emphasis option was (is) there on every system, all the way from U-Matic/F1 to the later DAW-based ones (like Pyramix) - and we were never asked to actually use that option. Nor did I receive a premaster encoded with it. Should be said that my «context» was the Norwegian market, neighboring Sweden was way ahead, due to exports on par with UK or even US. So, when CD covered most of our market, most players had decent (enough) DACs - or dithering to overcome the worst of it. By ca 1991, DAT became the (flawed, but 16bit) choice for digital premasters, and although our Sony PCM-7030 could handle PE, few machines did. As you may know, the more audiophile aspects have had little «space» in our daily grind. Kinda sad, as we all want music to «move» any listener. The ever giving gift is to «bridge» the artist and the listener, by whatever means we may master (bad nonintended pun)… Again, very nice presentation!

[@EzeeLinux]

Thanks. I can relate...My background is in audio for radio and I have used everything from tape to DAW's. I really appreciate your feedback! :)

[@net_news]

your videos are golden my friend. 🙌

[@maxbauer1633]

Although rarely used, there exists the capability for standardized emphasis in Red Book CD mastering. As CD players were originally implemented with affordable 14-bit converters, a specification for pre-emphasis was included to compensate for quantization noise. After economies of scale eventually allowed full 16 bits, quantization noise became less of a concern, but emphasis remained an option. The pre-emphasis is described as a first-order filter with a gain of 10 dB (at 20 dB/decade) and time constants 50 μs and 15 μs.[1] wikipedia CD pre-emphasis is a process that increases the magnitude of some (usually higher) frequencies within a frequency band relative to the magnitude of other (usually lower) frequencies in order to improve the overall signal-to-noise ratio by lowering the frequencies during reproduction. Pre-emphasis is commonly used in telecommunications, digital audio recording, recording editing, and FM radio broadcasting. When pre-emphasis is present in a track, this is sometimes indicated by a check mark in the Pre-Emphasis column in the Import Audio CD dialog . steinberg wavelab (translated from german)

[@b.powell3480]

This is similar to FM stereo preemphisis and deemphisis, I used it when recording on cassette tape

[@ConorHanley]

I have a few CDs with pre-emphasis from years back but I recently came across one CD in a re-released box set of piano music that had one CD with pre-emphasis amongst five. Thought it odd that they hadn't removed it for the reissue. If you run windows, dBpoweramp CD Ripper deals with the issue when ripping and there might be others.

[@LapisandHamtarolover]

I remembered we chat about this topic nearly fifteen years ago regarding with tapes on KZbin inbox back in the late 2000s early 2010s. Memories. PS; record and replay curves are handled separately in the tape world because of the electromagnetic properties of magnetism and electricity interaction. It is more complementary in the disc world with the accuracy of the sameness of the curves. Also because with records the whole thing is physical whereas tape is electrical due to the requiring of power for tapes whereas it is acoustic for records.

[@EzeeLinux]

Thanks for the feedback.

[@davidatrakchi2707]

You certainly have tought me something new! Thanks

[@Digi4u]

I bought that same Denon CD player back in the days when it came on the market, around 1989-90. It served me well for many years but some years ago it went kaputt, and got me a new Denon, now a DCD-500AE. My impression is that the one I have now is not as good as the DCD-810. I do remember there was a light on the 810 when there was a pre-emphasized CD, but can't remember which ones. I do have some Andreas Vollenweider ones you mentioned, (nice electronic harp sounds), as well as the Dire Straits "Brothers In Arms" one. On that list you mentioned with pre-emphasized CD's that is not correct, I do have some on that list like the Steve Roach ones, as well as The Human League one, as some others. Now the question is, how to check if the CD is pre-emphasized or not ? My new Denon CD player has not an indicator for that. My other Denon gear I purchased back then like the receiver and tapedeck, is still in excellent shape :o) Thanks for the video, greetings and salutations from Belgium.......Patrick

[@EzeeLinux]

There's really no way to know other than ripping it with software that ignores pre-emphasis. On Linux, there is a program that will tell you if the flag is set once you rip the CD but it's a bit cryptic to use from the command line.

[@stevesutcliffe5805]

Hi there, I use a marantz CD 52 mk2 , feeding Meridian converter model 203. It has a EQ light on it. That lights up when I play my copy of Pink Floyd the wall CDCBS88485. It’s a Columbia CD manufactured by Sony music in Australia, I’ve had it for ages. It’s quite a quiet sounding CD. I ripped it on an old iMac years ago, and made a CD copy which has no pre-emphasis. And when I play it back they sound the same but the EQ light doesn’t illuminate.

[@prep74]

That CD is considered one of the best sounding versions of The Wall. The similar 83/84 Dark Side of the Moon with pre emphasis is also a direct transfer from Sony's master tape used on the 1977 Japan pro use LP. Rare and sought after by audiophiles.

[@Seiskid]

10db is a lot. You'd definitely hear that if its misapplied. I agree with you that it's kinda pointless on this low noise floor medium, which is probably why they dropped it. Most emphasis / deemphasis circuits in domestic equipment are an approximation because they used standard value resistor-capacitor values in the filter, choosing values that were "near enough". That's definitely the case with cassette decks, as a result many of them sounded dull because they were over de-emphasized. Reworking the values slightly to match the head can greatly improve frequency response.

[@dab9742]

10 dB à 100 Khz, ça m'étonnerait qu'on puisse l'entendre, même un enfant, avec ses oreilles neuves ne perçoit que jusqu'à 20 Khz ! 😉

[@myownbiggestfan]

I don't want to see *a* seperate video about *a* cd player from 1990. I want a *lot* of videos about *all* the cd players from the 1990s.

[@peterofenback9263]

A light for deemphasis can also be found on the Hitachi DA-1000 and its clones. This is a device from the early 1980s.

[@Abyss60]

Good evening, I use a Pioneer CD player, so 1 or 2 DACs, to connect an Apple phone and the sound is very good. The iPhone phone serves as a network player and it's very good.

[@NackDSP]

At 6:00 There is a bad assumption. Digital de-emphasis filters are going to be superior to analog filters. Digital filters are exact and matched perfectly for each channel. To utilize the full dynamic range after digital filtering it would simply require an extra two bits in the DAC. So an 18 bit DAC would be required to play back the digitally filtered 16 bit audio. Not a problem with any modern equipment. Of course most people can't hear the difference between 12 bit audio and 20 bit audio, so it is practically irrelevant.

[@EzeeLinux]

I didn't assume anything... I asked a question. Yes, if you have a DAC that has the extra bits than you would be right. However, I wouldn't put it past cost cutting designers to just apply the curve without the extra headroom and lose all the resolution in the highs that you would supposedly gain.

[@ClaytonMacleod]

@NackDSP It just uses simple crossover filters. There shouldn't be any reason for there to be any practical difference between doing it in the analog or digital domain, other than worrying about component tolerance. It's just first-order high/low crossovers with centres of 3.18 kHz and 10.6 kHz. It's not complex EQ or anything.

[@POEMS466]

Ok. I've got too many songs to alter. So, can this be compensated for in playback through a hi-fi stack with a 10 band graphic equalizer? If so, then what are the optimal low & high end settings?

[@EzeeLinux]

That's not the right kind of EQ... Yes, you can lower the highs but you're introducing phase shifts. Unless you have a lot of very early CD's from the early 80's you probably won't have to alter anything.

[@craigtheduck]

god this reminds me of the videos from the old days, like the video where you ripped multiple CD copies/masterings of the same billy joel album 🥰🥰

[@EzeeLinux]

You've been around a while. :)

[@andrewlittleboy8532]

I have several cd's with pre-emphasis, an original Japan Harvest Dark side of the moon, Micheal Jackson Thriller and a Tom Petty - Southern Accents. My new Denon cd player has the de-emphasis circuit and also my Tag McLaren DAC20 has an LED to indicate it being decoded. I expect many modern Dacs no longer decode it, even using a cd player as the transport as a Bryston DAC I owned wouldn’t decode it. I’ve also discovered that even making a cd image and copying the cd back to a cd doesn’t copy the pre-emphasis flag. When ripping these cd's to a hard drive server didn’t copy the flag so sounded overly bright. Adding the decoding using software doesn’t sound as good as using real hardware.

[@EzeeLinux]

It would depend on how many CD's you had that were made with pre-emphasis. They are quite rare these days. I only started paying close attention to it when I started collecting early CD's.

[@Not-Only-Reaper-Tutorials]

I think because the early CDs, when the CD readers were out, the available DAC were not the ones of now a days. So the Pre-Emphasis served to that purpose: to compensate the poor-DACs back in the days. Rapidly the DACs improved and pre-emphasis on CDs turned out to be useless.

[@ericcrippen8634]

It's possible that the cds on the emphasis list are correct... there are different variations, however uncommon, that have the same name track with a different version, so the disc may be mastered differently for that country. I've had to buy Asian cds because a specific version of a song I was looking for was only available in that market for that specific year. I even have a promo with incorrect time stamp.

[@NipkowDisk]

My ancient Denon DCD-800 had an "EMPHASIS" feature which lit up when certain CDs were played, most notably my Claude Bolling CD where he played a bunch of Duke Eliington tunes. I wonder if it was related to this?

[@EzeeLinux]

Yes.... That means your CD was recorded with pre-emphasis.

[@NipkowDisk]

@@EzeeLinux Thank you. A 36-year-old mystery has now been solved!

[@NipkowDisk]

@@EzeeLinux It might have helped if I would have watched the entire video; I see you have a DCD-810 which IIRC succeeded my '800. Sorry about that. Oh, and I also think the Denon CD players were among the best.

[@Wurlyscope]

I have a CD compilation of The Byrds which is hard to listen to without lowering the high frequencies. It's the Columbia CK 37335 The Byrds - The original singles 1965-1967 volume 1. Thanks for the video.

[@Meteotrance]

Does Izotope Mastering software manage that ? I have a noise shaper with a my plug in version that can filter the extra frequency of my high res recording to a regular 16 bit PCM master, some of my new DVD and bluray player do an amazing upscale of my down convert master, but if i use the option to cut some noise shaping or dithering filter, it cut the extra frequency, the cool thing is when i listen my burn CD to a Laser disc player by Pioneer it sound realy well and less bright than on my player that make an up convert sampling, in FLAC at 24 bit no problem i don't need to add some extra stuff from izotope because it could ruin my original mix that was already EQ,comp and limited for optimal listening, i also try to not overprocess a digital take that sound already good, i add EQ and compressor only when i need to tame a very hot signal, or to leveling one that are too weak for being listenable on the mix, so gain staging , leveling and panning is the first thing i do before making shit with an EQ. Digital recording have enough headroom to make music breath ...

[@EzeeLinux]

You can do this with any software that has an accurate EQ curve function that does not phase shift. :)

[@jairoalbertomunozceballos7450]

Hola espero que te encuentres bien Te voy a corregir como lo pides en el video Para el sistema analógico las frecuencias bajas no se potencian antes se reducen porque si no los surcos serían grandes o muy grandes

[@AK-vx4dy]

I read many books on digital formats but never heard about this in CD case, what is puprose of it? Nosie level?

[@EzeeLinux]

Noise, improved resolution, maybe?... That's what I am asking in this vid myself. :)

[@AK-vx4dy]

@@EzeeLinux I wonder if cheaper players ignored this bit because when I first time heard CD it seemed very "clicky" and over "sharp". But maybe it was only shock in contrast to tapes and fm radio...

[@EzeeLinux]

@@AK-vx4dy I've never heard of any players not following the Red Book standard myself. Some of the early players sounded awful, though.

[@AK-vx4dy]

@@EzeeLinux But deemphasis was done in digital domain or switched on/off some analog filter ? I thought that bit beend decoded but done nothing or done it very poorly. My country was late to the party, so many cheap compaines flooded market already.

[@EzeeLinux]

@@AK-vx4dy The de-empasis can be done both ways.

[@RobWhittlestone]

Fascinating video! I thought anyone who is a vinyl nerd knows about RIAA equalisation. As a HiFi guy for 50 years, having owned a Denon as my first CD player in the mid 80's I have never heard of pre-emphasis! Does anyone know if any of the Beatles' Blue Album had this? I find my copy quite trebly. My CD player in the 90's was a Pioneer PD9100 - a great sounding player. Now I'm running a Primare CD32 with a Topping D90 DAC - also excellent sound.

[@EzeeLinux]

No Beatles were ever issued with pre-emphasis. They didn't start putting them out until 1986

[@RobWhittlestone]

@EzeeLinux Excellent! Thanks for the quick response! I was late to the party buying my Denon CD player in about '85 or '86. All the best,, Rob in Switzerland

[@act.13.41]

I can't help but wonder if it had something to do with Dolby cutting off the highs as it reduced the noise.

[@EzeeLinux]

Apples and oranges. Pre-empthasis is different from active noise reduction. :)

[@Douglas_Blake]

FWIW ... Pre-emphasis pairs with De-emphasis. When recording on vinyl they use RIAA Pre-emphasis to boost highs in comparison to the lows. When you play the record your pre-amp has RIAA De-empahsis to reduce highs, restoring the normal tonal balances.

[@ClaytonMacleod]

The RIAA curve uses three time constraints, not one. On the production side it uses 3180 us (50 Hz) high-pass, 318 us (500 Hz) low-pass, and 3.75 us (2122 Hz) high-pass for its filters. The general result being that it cuts the low bass quite a bit, kind of leaves the upper bass and lower midrange alone, and boosts the treble quite a bit. The graph output of this kind of looks like a medium hill followed by a small valley and then a larger hill. Then it uses the opposite filters on the playback side in the phono pre-amp stage, so 50 Hz low-pass, 500 Hz high-pass, and 2122 Hz low-pass filters to reverse it.

[@Douglas_Blake]

@@ClaytonMacleod Thanks for filling in the pre-emphasis details. I was trying to remember the knee points and decided not to try guessing them. Of course the opposite de-emphasis curve is required on playback.

[@ChrisMag100]

My Mofi copy of Dark Side from the 90’s triggers deemphasis on older DACs like my Sonic Frontiers SFD-1Mk2.

[@marco31]

Help, the audiotrack of this video is in spanish and i can't select english. Only french, italian, spanish and german are available. That creepy sounding robotic voice drives me crazy. Where is the real Joe?! EDIT: I reloaded the video and now i can select the original english audiotrack, thank god. But it still annoys me that youtube messes with the audio of the videos. By the way the title of the video is now in german for me. Well, at least i can hear Joe's voice now.

[@EzeeLinux]

Weird. KZbin is experimenting with AI generated translations... Seems there are some bugs.

[@ahmedsarker01]

Sunday greetings ✨

[@MrTorbjorn22]

Your vocal is preempathized for sure.

[@stevebennett9750]

Sadly most modern CD players do not have a de-emphasis circuit so playing these CD's with Pre-emphasis sound overly bright on those players.

[@prep74]

Not entirely true. Any CD player displaying the compact disc symbol must adhere to red book specs. That includes the ability to de emphasise CDs.

[@andrewlittleboy8532]

That is true, many modern cd players don’t bother adhering to the redbook standard these days.

[@EzeeLinux]

I miss the days when new gear got a proper test on a bench and someone would publish those results. These days, no one cares and so we have garbage reviews that talk about "sound stage" instead of measurable numbers. Some very extensive machines can't play continuously and glitch between tracks on cd's where tracks change with audio as in a live recording. Stupid.

[@wildw1ng]

Category 1

[@elmonte5lim]

I watch this in English, but when I download it, the audio track's German, no matter how I faff about with settings. I'm using Video DownloadHelper in Firefox under Pi Os on the Pi 5. Pity meine Deutsche ist schlecht. Oh well. Might be interesting as a curiosity. I'll give it another go tomorrow, after a reboot. Other than that? Beats me.

[@emilspec1227]

KZbin added a new feature where you can choose an AI generated audio in another language. Maybe you have to pick english when downloading.

[@MrSlipstreem]

I wonder if this other not-to-be-mentioned KZbinr is the one who doesn't understand how Dolby noise reduction (of any type) pre-emphasis/de-emphasis works and tells everyone to not use it. The additional frequency range offered by Dolby C on cassette recordings (particularly with Type I tapes) seems to whistle straight over his head.

[@EzeeLinux]

I don't think it's the same one. I was referring to a guy who mainly talks about new gear. However, there is a lot of stupid on KZbin so I'm not surprised. LOL :)

[@AshnSilvercorp]

Uhh... was this channel always in French?

[@bourbonick]

check your settings, lol

[@AshnSilvercorp]

@@bourbonick now it's in English when I check again... YT what on earth?

[@miojao-r7r]

KZbin is starting to auto translate to the language you have selected... what fresh hell is this