Axiom Home Page Forums General Discussion Technical Questions HDCD vs CD

I came across an album that is on HDCD and CD (and vinyl). (1) Is HDCD that much better than CD? I'd also like to put the album on my iPod in an Apple Lossless codec. (2) Will I run into any problems there? The CD is about $10 and the HDCD is about $30. It would be nice every now and then to listen to it in higher quality (with my home theater equipment), if there is that much of a difference. It is too bad that the hybrid SACD has gone OOP. Some yokels on the Amazon Marketplace think that it is a collectors item and want $258 for it used. I wouldn't pay that kind of money for even my top-three-stranded-on-a desert-island albums.

I have a few CDs that are HDCD and the technical concept behind them seems to be that the master recording is done at an expanded frequency range so compared to the average CD the most noticeable difference is they tend to play significantly louder. With the limitations of 16 bit technology, whether they are audibly any better than a normal CD is somewhat debatable especially with that difference in volume AND the varying quality of all recordings done in the studio anyway. I can't, though, ever recall paying a premium for them and in your example three times as much? Forget it.

Hi Nick B,
I own a few CDs which are HDCD "encoded". To play them back you need a player which is capable to handle HDCD. The difference is subtile. I think that the skill, knowledge of the recording engineer and the care he took for the recording session are much more important. Many HDCD CDs were from Reference Recording and the engineer was Prof Johnson; they are great recordings. I also own one of Madeleine Peyroux - Dreamland which is spectacular and was awarded a Record to Die For by a Stereophile reviewer.
The best recordings which I have auditioned so far are from AIX Recordings Blu-ray in 7.1 Dolby TrueHD "stage" mix or their Audio DVD in 5.1 MLP. 2L Recordings from Norway also offers exceptional recodings (Blu-ray and SACD in multi-channels) where as AIX REcording you are with the musicians.

JC:

There were also a number, although not many, mainstream recordings done using the HDCD process. Back a few years ago my wife bought a "Bee-Gees" CD that was HDCD encoded and that is where I noticed the difference in the volume level.

Hi,

I'd agree with everything JC noted about HDCD, and only add one thing. If memory serves, HDCD is essentially a dynamic-range expansion system, adding as much as 12 dB to the dynamic potential of a recording. In tests I did years ago, you could detect the difference (barely). The HDCD decoding was licensed out to some manufacturers but I don't think it was all that successful, mainly because the difference between an HDCD recording and non-HDCD playback was so difficult to hear. Frankly, the conventional CD format is able to encompass the entire dynamics of any orchestral/musical performance so I didn't really see the point of HDCD.

As JC pointed out, Keith Johnson is an excellent recording engineer and I've used several of his recordings as definitive test discs for listening tests, HDCD or not.

Alan

Alan, the value of HDCD is that in enables putting compressed and less compressed versions on one disc, but I would agree that with the dynamic range of CDs, what is the point. My take away is that if you use ReplayGain, you may as well use the HDCD version and make use of the headroom.

Chris

Oh great, another headroom discussion.

Hi ChrisF,

Some might have misunderstood my comment on HDCD. I didn't mean that it's a dynamic-range expansion system for ANY recording. The recording must be HDCD-encoded during recording/mastering and played back via HDCD-enabled player in order to realize the theoretical enhancement of dynamics.

In the days of analogue tape and vinyl, in addition to Dolby SR, there were various compression/expansion systems, sometimes called "companders", to get peaks way above the noise floor and reduce the limitations that analog tape and vinyl impose on playback dynamics and noise floors. I still have an old dbx decoder box that could only be used for dbx-encoded vinyl LPs. When everything was set up right, those were amazing, with inaudible surface noise/tape hiss, and dynamics that approached CDs. The system failed because of the incompatibility of dbx LPs for playback without having to purchase the accessory decoder box.

By the way, Chris, what's "Replay Gain"?

Regards,
Alan

Ha ha, "compander" sounds like a word someone says when they are trying to appear smart.

Or it's the commander of all pandas.

CV, the scary thing is that I thought that too.

Yeah, now might be a good time to see J.P. Of course, if it's scary like in a horror film, he could be the skeptical mental health professional that the panda commander comes to kill after he laughs off our sessions with him.

J.P will, of course, be wearing his red Star Trek shirt for that, too.

Heavy-handed foreshadowing raht thar.

If he forgets and wears a Simpsons t-shirt instead, that will only infuriate the panda commander more.

Companders are COMPression / exPANDER units.

The theory (and practice) was that if you expand the dynamic range on playback and lower the level of the quiet stuff, you would also be pushing down the noise floor.

They're still in use in pro audio equipment racks, and I've wondered about an expander for my HT. Then I remember that I don't really have a noise floor, practically speaking, with my digital sources.

Hell, I still want a subharmonic synthesizer, which were popular enough for years that you could buy them at Radio Shack.

P - Sorry to have interrupted the Panda stuff!

It's okay, Mark. You may have just saved J.P. at your own expense.

Yeah, way to go Mark. You killed our panda buzz.

Now I'm thinking of a panda in a bee costume drinking an espresso.

And saying "D'Oh!" after every sip.

ha, ha! Stupid word. Loved the commander of all pandas idea, CV, (note to self: start writing cheesy screenplay featuring pandas---and a compander, of course, and pitch to Dreamworks).

Cheers,
Alan

Alan,

Replaygain is a scheme that objectively measures the loudness of music tracks or albums encoded to flac, ogg, mp3... and adjusts the volume to a standard loudness. This results in reducing the volume for most recordings to minimize the number that would end up clipped, so if an HDCD recording can make use of some of the (digital) headroom, then great. It is handy for mixed playlists or even one album following another, and if your DAC has more resolution than the recordings, I don't think anything is lost.

Wikipedia has a reasonably easy-to-understand description of Replay Gain.

I have tagged all my 10,000+ tracks with album and track Replay Gain values. With my SqueezeBox I enable "Smart Gain" for playback. This means that when I play a mix of tracks from various albums there are no wild swings in loudness between tracks because it uses the track Replay Gain value to normalize the volume. If I play an album, it uses the album Replay Gain value, which is the same for all tracks on the album, so the tracks sound correct in volume relative to each other as the mastering engineer intended.

Back to HDCD. Again, Wikipedia has a good description.

My take, after trying to hear the difference between an HDCD decoded and not decoded, is that I can barely tell the difference.

On the other hand, it seems to me that when a mastering engineer opts for HDCD it probably means that he/she feels that the source material is of sufficiently high quality to warrant it. Perhaps also the engineer will take extra care and pride in trying to make the recording sound good? In other words, HDCD is an indication that the sound quality has a higher probability of being good.

Thanks, Henry66 and ChrisF for the replay gain explanation. After I posted my question, I came across a reference to it on another forum, where I was seeking info on how to revive my frozen Sansa Clip+, which does nothing but display the SanDisk logo. I think it also has that option, or you can download an "app" to tag all your music with the replay gain values and the Sansa Clip+ will read those and adjust playback gain.

Alan

It sounds like you bricked your Clip+

If your Sansa freezes on power-up, the most basic first step is a soft reset. In the case of the Clip+, this is done by simply pressing and holding the power button for 15-20 seconds, then releasing the button. This powers the device off and resets it.

Then, try powering up as usual. If the device will not operate normally, is this happening after transferring some music to the device? You may have a corrupted music file. In this case, go to your PC first. Open a Windows Explorer window via My Computer, or press [Windows Key] + E.


Press and HOLD the center button on your Clip+ while connecting it to the USB port. In a few seconds, the Clip+ will appear as SANSA CLIPP (E: ) for example. You can then release the center button. Right-click on the icon, then select properties, then the Tools tab, then click on the Check Now button under error-checking to check the volume for errors.


http://forums.sandisk.com/t5/Clip-Clip/SANSA-CLIP-FROZEN/td-p/137832

Here is info if you have make changes to the firmware.

http://kb.sandisk.com/app/answers/detail/a_id/185/~/sansa-clip-player-freezes-on-the-%22sandisk-sansa%22-screen

Thanks. I've tried all those fixes and nothing. I dropped it on the pavement as I got out of the car. The trouble began after that. It froze when it was "refreshing your media".

When I do the center button thing, my laptop doesn't recognize the Clip when you connect it to the USB.

It only turns on and off. I think it's likely toast.

I don't think I ever got an answer to this and I am looking at purchasing an HDCD. It would be nice to be able to listen to the disc on my home theater system through my Oppo player. But, I would also like to be able to put the tracks on my iPod in AAC lossless format. Will I run into any issues doing this with an HDCD disc?