Much to my surprise, it seems the long-time proponent of HDCD, Reference Recordings, isn't using the technology to its fullest potential! For example, the two Joel Fan CDs I have, catalogue numbers RR-119 and RR-134, have no PE, LLE, and TF; on the well-reviewed Elgar and Vaughan Williams disc, RR-129, I've observed only TF. Another example: the CD layer of their Dvorak and Janacek SACD (FR-710SACD, released last year, 2014) has no PE or LLE, but at least TF fickers. I don't have all of their material to confirm my observation, but it seems RR may have decided sometime after 2008 it wasn't worth turning on PE; my last true RR HDCD disc is their 'Tempest' recording, RR-115, and it has a copyright year of 2008, the aforementioned RR-119 of mine has a CR of 2009.
Hello Veloroad,
Superb analysis! Here is my take:
1) TF will always be flickering. The PM A/D converter has two different anti-aliasing filters that it automatically selects when recording and this feature cannot be disabled. However there is no possible way to "decode" this. No HDCD player ever made has more than one playback filter, so there is no need to even encode the information about the A/D filter in the "hidden subcode".
I suspect that their original intent was to have two different reconstruction filters in the player, but they were beat to the punch my Ed Meitner's patent when he was working for Museatex. The fact that the flag even exist is probably an anomaly that was easier to leave in than to remove. Any disc ever made with a PM converter (Model One or Model Two) will activate the TF flag (with pop music it usually changes whenever the drummer hits a cymbal), but it is only of theoretical interest, as there is nothing to be done during playback.
2) LLE is next to useless. It only comes on when the signal level falls below -45 dBFS. This is basically never during pop music, and only for very short times during classical music. I've only ever seen it turn on with a very quiet passage with one or two instruments playing.
3) PE did provide an extra bit of dynamic range (6 dB) at the top end, but it also cost a bit of dynamic range at the bottom end because that's where they put the "hidden subcode". The net gain was really pretty minimal.
The reason that they don't bother to use it any more for their recordings is that when played back on a non-HDCD player, the dynamic range of the music will be compressed by 6 dB.
Their original plan was to "take over the world" and have all CD players use their technology. That plan was sidetracked by two events:
a) The introduction of true high resolution formats such as DVD-Audio and SACD, and now high-resolution files available in download format. I have the entire Beatles catalog in 44/24 from the USB thumb drive that came in the green metal apple. I can download all kinds of true high resolution files from PonoMusic, HD Tracks, and many other places. The masses are happy with MP3. People who really care about quality want something better than a slightly hot-rodded 44/16 CD. Probably 20% of my music collection is now high-resolution digital files. The very best that HDCD could offer is the equivalent of 44/17.4 - not exactly earth-shattering news!
When HDCD was introduced PM claimed 20 bits of resolution, but that was just marketing fluff. Most of the "extra resolution" actually came from dithering, but every A/D converter in the world has dithering now, and even the early Sony converters that didn't have built in digital dithering would be very nicely dithered by the tape hiss during the transfer from analog tape.
b) HDCD lost out because of the same reason that FireWire lost out to USB - money.
It's all about money, control, and power. PM wanted to make money by licensing their technology. It's not worth it to pay the license unless you absolutely have to.
When FireWire was introduced, it was far faster (400 Mb/sec) than USB 1.1 (12 Mb/sec). But the licensing for FireWire was $1 per port while USB was free. Once they introduced USB 2.0 at 480 Mb/sec), it was faster than the original FireWire, but it was still free. Why pay $1 per port for something that is slower than the free stuff? That's why they came up with FireWire 800 (800 Mb/sec). But it was still only marginally faster than USB 2.0 and died shortly thereafter. Apple kept using for a couple of years and then dropped it from their products.
Nobody wants to pay Microsoft a $10,000 license fee plus per-device royalties on HDCD patents that have expired, so there are fewer and fewer and fewer products that will decode HDCD. The only reason to do so is for the collection of legacy discs that were made from around 1998 to around 2006. No smart manufacturer is going to add it now, as it won't sell many extra players.
As far as decoding, from around 2000 to around 2004 the very best sounding digital filter chip on the market was the PMD-100 that also included HDCD decoding. To even buy this (relatively expensive) chip, you had to have a license ($5000 at the time, but raised to $10,000 after the Microsoft acquisition). The problem was that the factory that made the original chips used a 600 nm process. When they shut that down, PM would have had to pony up another $500,000 or so to get new chips made. (For reference, the fastest chips made today use a 16 nm process - finer process parts run faster, are smaller and cheaper, and consume less power.) PM apparently didn't have the money so sold the business to Microsoft. Microsoft immediately dropped all hardware support.
The only way to decode HDCD today is to buy a programmable digital filter and license the HDCD code from Microsoft. There are some DVD and Blu-ray players that do this, but almost nobody makes a CD-only player any more and the ones that still exist don't use fancy programmable parts that could even use Microsoft's code. The patents have all now expired, so reverse-engineering is legal but probably not worth it to most companies.
Reference Recordings has recognized the fact that HDCD is dead and that only a small fraction of CD players can even decode HDCD's one feature that even really requires decoding (PE), so they have faced reality and make CDs without HDCD encoding. If a customer really wants better sound quality, they are going to buy a true high-res file (eg, 192/24), not something that is only literally about 1 bit better - about 44/17. There are far more playback devices that will play 192/24 than there are that will decode HDCD. Heck, even the crappiest smart phone on the market will play back a 48/24 file. Most people that buy physical discs these days either want true high res or they want to play it back in their car stereo. I don't know of any car stereos that will decode HDCD.
Obviously these are just my opinions. There is a lot of speculation here. You would have to ask Reference Recordings why they stopped using the HDCD features to know for sure. Clearly they still believe that the PM converter is the best sounding one, or they would switch to another brand. When they remastered the Beatles catalog in 2009, the engineers spent a lot of time comparing the sound quality of A/D converters. The best one at that time (in Abbey Road's opinion) was no longer the PM but instead they chose a Prism. The Prism is a very good one, but there are likely even better sounding ones available today, almost 7 years later. It's hard to believe that nobody has come up with a better sounding A/D converter than the PM in all of these years. The Model One was introduced over 15 years ago, and the Model Two was basically the same except it added higher sampling rates. It's still a great converter and well respected, but no longer considered the "King of the Hill" that it was in the early 2000s. Do you think that nobody has made a better sounding CD player or D/A converter since the year 2000?
It is only through Foobar that we can even see which HDCD features are used and which ones aren't. This is the only way to distinguish a "real" HDCD (that requires decoding for best sound quality) from a "fake" HDCD (that cannot be decoded at all, but was simply made using the PM A/D converter).
I hope this helps, and I hope it makes (at least some) sense.
