-=> On 04 Aug 96  06:34 you wrote to me <=-
GG> Most of the other hyped formats out there (HDCD) and what not
GG> are just not neccessary.  (the differences are minimal).
GG> The actual HDCD chip is nothing special in my opinion.
 BG> While I'm not exactly sure just what is involved in the HDCD
 BG> chip, 20 bits is considered sufficient resolution in pro audio
 BG> who was initially satisfied with 16 bits(a practical limit for
 BG> computing equipment at the time). An additional 2 bits for
 BG> dynamic range seems to make the difference, along with two bits
        First of all, HDCD is not the same as true 20-bit.  It has not
been proven to be any better than Sony's SBM or formats from Meridian,
Apogee, etc.  What's worse about it is that it requires a decoder just
to get "normal" sound.  I have reviews that swear that without a
decoder, things like the piano don't sound "right."  (I have one HDCD
disc and doesn't have piano on it, so I can't comment on that
particular claim).  The problem with that is you are limited in your
selection of D/A Converters/CD players if you want HDCD decoding.
Since it's not been proven to be any better than something like SBM,
why use something that requires a decoder when the others don't?  I've
got a list of reccomended CD players from someone I highly trust on
rec.audio.high.end (very recent...just two days ago) and none of them
have HDCD.  Nor would I want to hand out money on something that is
designed to milk the market like the HDCD chip.  Of course Pacific
Microsonics wants to sell HDCD chips for every CD player out there.
They stand to make a *lot* of money.
        HDCD *does* increase the "perceived" dynamic range of a 16-bit
disc, but then again, so does the other formats.  The problem is, most
recordings (and almost all analog recordings) have noise floors that
are not even 16-bit, let alone 20-bit, so most of this stuff is a bit
of a waste at this juncture anyways, although certainly it doesn't
hurt anyone, unless the consumer has to purchase a decoder for
something that makes magical claims, which HDCD does.  The only proven
thing HDCD has is slightly increased dynamic range, and like I said,
so do the others.  The other initial nonsense claims that were made by
Stereophile and Audio have largely been retracted.  Most admit that
HDCD recordings sound so much better because of the recordings
themselves, not necessarily the HDCD format.
        As I said, I've got a HDCD disc.  It's called /Pomp and
Pipes/.  It does sound pretty darn good.  But then again, it's not the
best sounding disc I own, either.  The best discs I have don't make
any claims about any special formats.  The one 3-disc set was
orignally recorded back in 1982-83 and I'd rate it one of, if not the
best recordings I have.  Admittedly, it probably wasn't transferred to
CD until much later, but not that much later.
        So, forgive me if I'm skeptical about the effects of HDCD
beyond a limited dynamic range improvement.  
  
 BG> of digital noise called dithering which as strange as it sounds
 BG> actually helps to make 18 bits of data seem to be 20 bits since
 BG> the two least signficant bits are randomly changed. Why adding
 BG> noise makes it sound better is another whole conversation, as 
 BG> well as jitter. 
        Yes, I'm quite aware of the effects of dither.  Random dither
can be applied on a playback DAC as well.  It won't do much good,
however.  Dither is only effective in the recording process.  And it
is generally used with *all* CD recordings, not just 20-bit conversion
CDs.  Otherwise, you'd have nasty granulation noise, which is just not
the sort of thing the ear likes to hear.  Dither is added to the
signal before being sent to the A/D converter, 20-bit conversion or
not.  This doesn't keep companies from selling dither circuits in
playback DACs, however.  Anything to make a buck and claim "20-bits"
even if those extra bits are just random white noise and completely
uncorrelated to the signal. 
        As for more dynamic range, I'm all for it.  But the truth of
the matter is, it's just not realized.  Even if the recordings do
contain more than 96dB of dynamic range (most do not), there's still
the matter of playback in the home.  Even if you play your stereo with
peaks of 120dB, you're still not going to hear the full dynamic range
of a 16-bit CD unless your average room noise level is less than
24dB!  The "typical" room noise level is more like 60dB.  Really quiet
rooms might be 50dB.  You'd practically have to live in an anechoic
chamber to get that low a level.  Now I don't know about you, but I
certainly don't listen to even 120dB peaks.  It's just not good for
the ears.  As for whatever "magical" effects people associate with
20-bit, well, whatever.  Just don't charge me for some ridiculous
format like HDCD to get those extra bits.
        I'm all for the new DVD CD format, but not so much for 20-bit
at 96kHz (I think more care in the recording/mastering processes and
better mic technology etc.  would do *far* more for your average disc
than just adding more bits), but rather for multi-channel sound
(stereo surround etc.) which would enable a more natural and realistic
soundstage for live recordings and provide interesting effects for
certain surreal music (e.g.  Pink Floyd) and even different
perspectives (e.g.  sitting in the middle of an orchestra as if you
were playing with them instead of the typical audience perspective,
something I can appreciate as a former 1st chair sax player.)
   
 BG>  While the differences may seem to be minimal, isn't that what
 BG> makes high end audio special? Why we spend so damned much money
 BG> to get that additional performance? I do agree that foriegn
        Oh, I'm for minimal differences, just ones that can be heard.
When you take a superior recording like /Pomp & Pipes/ and then
pretend that the reason it sounds so good is the HDCD instead of the
recording, then you're doing a major disservice to the audio
community.  HDCD is useful, but it's not magic like some would have
you believe.  
        I admit it's *easy* to get caught up in all the hype of some
products.  The problem with digital audio is that it has largely
removed the "hobby" aspect of stereo reproduction.  I'm afraid some
people still cling to this aspect in areas where it's just not
possible (e.g. green pens).  I'd love to believe in magic audio
coasters and green pens and demagnetizers for non-magnetic media, but
I'm afraid it's just a load of hogwash.  Lately, however, I've seen
increasingly more evidence that points out some people who I thought
were beyond that nonsense are now starting to consider it (because so
many do believe in it...just look in rec.audio.opinion to meet the
happy Shun Mook Coaster cult).  I'm sorry, but I'm keeping my feet on
the ground and separating fact from fiction as best I can.
        Fortunately, there are a lot of industry professionals on
rec.audio.high.end and they provide a *lot* of factual information
anytime someone asserts a false technical claim.  It's also the
reason, the audio cults tend to *hate* that newsgroup.  They want to
believe and don't want anyone smashing their beliefs with science.
 
 BG> pressings have largely outshined domestic ones... but, there are
 BG> a few here that I do trust to be using the best equipment and
 BG> techniques in achieving among the best available. Folks like Bob
 BG> Ludwig, who uses HDCD considerably and someone I accept as
 BG> forgetting more about mastering than I'll ever learn! If Bob 
 BG> swears by it, I'd take a second look at your opinion of HDCD. 
        Just be sure you separate what's real from what's not.  HDCD
*does* insure a strict and clean production chain, which alone
provides far better results than what many albums go through.  There
is also a clear dynamic range improvement, technically, although like
I said, you're unlikely to realize this in the real world.  So, HDCD
is not total BS.  I'm all for the clean production chain (no extra
conversions between analog/digital, etc), but the actual encoding is
not really neccessary IMHO, especially when other formats don't need
a decoder.
 * AmyBW v2.14 *
... Quality Bass is like icing, but icing without CAKE is SICKENING!
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