Quote
Dr. Mark Waldrep (not verified) -- Thu, 06/25/2009 - 12:07

As the producer, engineer and purveyer of a catalog of High Definition music recordings (AIX Records does't release CDs or vinyl) and as a friend of Bob Stuart, I have to agree with RH regarding the move to higher resolution recording methodologies. The limitations of compact discs (44.1 kHz/16-bits, stereo) have been eclipsed for more than a decade with DVD-Audio and high definition PCM recording. I am not a supporter of DSD, the encoding format used on SACDs but do consider them in the HD realm. Vinyl, analog tape and standard definition digital are incapable of achieving the sonic accuracy of high definition PCM audio...and I believe the audiophile world is slowly begining to recognize it.

Recently, I did a large number of spectragrams of various recorded sources for a presentation I gave to the local audiophile society (of which I am a lifetime member). I examined a master analog 2-channel tape recording I made of a percussion ensemble in 1985 using my Nagra IVS reel to reel machine, tracks from the Reference Recordings HRx Sampler I (delivered on DVD-ROM as 176.4 kHz/24-bit stereo PCM files), several commercial CDs, a Grammy winning SACD and others, various MP3 files (from 64 - 256 kbps), a T Bone Burnett "CODE" track of John Mellancamps and a track from Laurence Juber's award-winning AIX Records DVD-Audio release (which is also available for download at iTrax.com).

I plan on posting the graphs and my observations on the iTrax.com webmagazine soon but the short story is that the MP3s were capped at around 16 kHz, tape was as good as tape can get (no safety copy of overprocessing) but failed to eclipse 20 kHz with any reasonable energy and had limited dynamic range, the CD squared off at around 20 kHz, the SACDs all clearly have the "cloud" of noiseshaping hash at around 30 kHz (not musical...just noise), the HRx recordings max'd at around 35 kHz (surprising for such a high sample rate) and Juber 96 kHz/24-bit tracks had meaningful content up past 45 kHz.

Given the listening that I've done on a very high end system (Benchmark, Bryston, Cardas, B&W 801 IIIs in my reference studio, it does make a difference when the source contains information above the threshold of hearing and has dynamic range commensurate with human hearing...especially when listening for extended periods. If you haven't experienced it...you cannot possibly know. But CDs, analog tape and vinyl just cannot complete with well done HD PCM. It's only disappointing that the audio community is locked so fervently into out-moded modes of thinking that perpetuate the formats of the past over real, audible and measureable improvements in audio technology and recording techniques. High definition music presented in surround is audio "at a whole new level" as Al Stiefel, the late head of the Rocky Mountain Audio Fest, commented after hearing our HD music sampler for the first time. I couldn't agree more.

Finally, AIX Records just completed our first Blu-ray sampler disc. It will bundled with the new Oppo BD-83 player. I'm excited because content companies like mine can finally deliver HD Video with HD multichannel audio...DVD-Audio can give you the audio but not the video.

I'm not sure that Blu-ray will be an audio delivery format or if it will suplant DVD in the short to medium term...the only certainty is the audio will endorse more bits and higher sample rate AND will move to multichannel presentations AND it will be delivered via networks into music servers (wired of wireless).
http://www.avguide.com/forums/will-blu-ray-make-it

It would be very interesting getting that AIX sampler with the modified Oppo, to save on shipping of a sole disc to Europe...

HD621, G98DH, G68ADV, Bc Acoustiqe ACT A3, 5200C DSP33, NuForce Reference 9 monoblocks, 2x SB3's, Velodyne DD-15 & DD-12 Subwoofers and a Meridian sub.