I was passed a link to your article on HD Audio by a friend at Intel this
morning. As the developer and owner of one of the largest catalogs of REAL
HD Audio, I would like to share some observations/comments on the world of
so-called "HD Audio" from an expert's point of view.

First, let me state that I'm a member of CEA, I am a friend of Elliot Mazer
AND I was at the HD Audio press event in Las Vegas that featured Elliot,
Jennifer Boone and Ray Kimber. I am the chief engineer at AIX Records based
in Los Angeles, California and have advanced degrees from UCLA in music and
CSUN in computer science. I have also founded and am the director of the
High Definition Surround Music Association, a non-profit dedicated to
supplying accurate information and demos of HD Audio.

Your question "But what exactly is high-definition audio?" is the primary
issue in the evolving world of so called HD Audio. Let me address this with
a definition that we adopted at the HDSMA.

HD Audio is music or sound that is captured from the acoustic source at or
near the fidelity of human hearing. In real terms, this means
recorded/reproduced sound that has a frequency response of at least 20 kHz
[with arguments made to double that number] and a dynamic range of around
124 dB or more [current equipment can handle near this amount].

The only consumer formats that have the potential to be able to accomplish
this level of fidelity are SA-CD and DVD-Audio. DVD-Video can do it for two
channels but NOT in surround because of the lossy nature of Dolby Digital
and DTS required on DVD-Video discs. This means that the products that
Monster Music calls "high-definition surround" music are, in fact, no better
than the surround sound in most movie releases. This is not HD Audio...even
if they call it that. This is another example of the Monster Marketing
machine doing it's thing.

Of the SA-CDs and DVD-Audio discs that have been released...most are NOT HD
Audio...but merely re-purposed recordings that were captured in the past
before HD recording equipment was available. Just because an older analog
tape is re-recorded at 96 kHz/24-bits doesn't magically make the sound
exceed the specs of the machines that first recorded the acoustic sound. The
best analog tape recorders can muster is about 18 kHz and 72 dB of signal to
noise ratio. This translates into a sample rate of  less than 44.1 kHz and a
bit depth of 12 bits...far short of the HD standard of 96 kHz/24-bits.
Again, not true HD. The sound is as good as the master tape...but not
better.

The same logic can [and should be applied] to downloaded music. What
MusicGiants.com is doing is laudable but it is NOT HD for the reasons stated
above. The original tracks were captured and processed with equipment that
was not able to meet the HD specs. For example, take the Beach Boys "Sloop
John B" that Elliot played for the press at the CES event. It was done on an
AMPEX 4-track recorder in 1966 in mono. The fidelity was pretty impressive
for the time...but could be easily contained in 12-bits and 44.1 kHz of
digital fidelity. If someone was able to time travel back to the session
with state-of-the-art gear...the quality would be vastly improved.

Jennifer Boone is right, the public is ready and very interested in higher
quality...but unfortunately, they are not hearing it! They didn't hear it at
the press event. They cannot download it from MusicGiants.com, they don't
get it on any Monster title and most of the content out there that is
marketed as HD Audio is not!

One final example. HD Radio. The HD in HD Radio by iBiquity doesn't stand
for High Definition! They don't claim that it stands for anything. The
Cambridge Soundworks guy told me at CEDIA that it stood for Hybrid
Digital...which is more to the truth. The bandwidth of the additional "HD"
stations is limited to roughly half the quality of the worst quality MP3
downloads...or 64 kbps! This is a deliberate attempt to confuse the public
and certainly not HD.

I would urge you to investigate the issues that I have brought out in the
overly long comment above. AIX Records produces and releases [on DVD-Audio
AND through iTrax.com] REAL HD Audio. We've won awards from the CEA and
Electronics House magazine for the fidelity of our work. When people hear a
truly impressive track in HD surround they flip out. I would be happy to
send you a copy of our award winning "A High Resolution Audio Experience"
disc...if you have a reasonably good surround sound system, you'll
understand why the first track beat out Diana Krall, Wynton Marsalis and
Sting for "Best Demonstration 5.1 track".