Robert C. Ludwig, Gateway Mastering, Portland, Maine

Recording Venue and Control Room Acoustical Treatments:

RPG Skylines ASC Tube Traps

Microphones and Microphone Preamplifiers:

Cambridge C35 Ribbon; Gates; Millennia; Neumann; Schoeps KFM 6 Stereo Sphere; Schoeps KFM 360 Surround Sphere

Analog to Digital Converters and Digital Processors:

Apogee Electronics Corporation; Benchmark; dB Technologies; Harmonia Mundi; Meridian; Pacific Microsonics; Troisi; Wadia; Z Systems

Tape Recorders:

Nagra D; Studer A80; Studer-Cello

Monitor Speakers:

Aerial Acoustics 5, 7, & 10; Duntech Sovereign; QUAD ESL ‘57 & ‘63; Shahinian Diapason

Headphones:

Sennheiser 580; Stax SR-Lambda Signature

Equipment Cases:

Porta-Brace

Clothing:

Liquids:

Poland Spring, Evian, Tropicana, Korbel, Veuve Clicquot

Music for a Glass Bead Game has achieved some notoriety as an "unlabeled HDCD disc." The issue of "unlabeled HDCD discs" is not as black and white as the public discussion to date might suggest.

First let me say that the HDCD processor box is a powerful tool, and like most powerful tools, in the right hands (Bob Ludwig’s) it can be used creatively to get inspiring results. I wouldn’t let it get near my artists’ work unless I believed it worthwhile.

It would be best to separate the discussion into two topics: the Pacific Microsonics box is one thing, the HDCD process is another. The HDCD process consists of some use of the Pacific Microsonics box in the creation of a CD, which is then played back on a CD player, that either has the HDCD decoder chip in it or not.

Most of the discussion to date seems to assume that the Pacific Microsonics HDCD box has one in and one out, no options and that’s it, so a disc is "HDCD" or not.

It’s a little more complicated. The Pacific Microsonics HDCD box accepts either analog or digital inputs. It has several processing options. It also has a re-dithering stage to output 16 bits for making CDs.

So there is an entire spectrum of creative choices to be made (I won’t tally up all the permutations). The most complete is putting an analog mike preamp output into the Pacific Microsonics HDCD box analog input, electing to use all the processing algorithms, and outputting encoded, re-dithered, 16 bits. My understanding is that this is how Reference Recordings does it.

Some people claim that a CD made in this manner, if its program material takes full advantage of HDCD’s dynamic and frequency domain processing, when played back on a non-HDCD capable CD player, can exhibit processing artifacts such as compression. I personally have not heard this, but I haven’t gone looking for it either. I respect the judgment of those who have.

Another option, the one we chose for Music for a Glass Bead Game, is to take a hi-bit digital source, such as from a Nagra D, and use the Pacific Microsonics HDCD box only to re-dither it to 16 bits. This use of the Pacific Microsonics box puts the HDCD flag in the digital word that triggers the light to go on, on an HDCD-capable player or converter. But the light going on does not necessarily mean that the original recording was made using the Pacific Microsonics HDCD box as the analog to digital converter, or that processing was used to try to stretch dynamics beyond conventional 16-bit CDs.

My hope is that by doing things this way, we deliver a CD that has the best possible re-dithering on any player, no potential negative aspects when played on a non-HDCD capable player, but nonetheless can take advantage of the flexible digital filter in a HDCD-capable player.

We had experimented some time earlier with HDCD, and the results were inconclusive. At some point there were apparently some software changes, and we revisited the issue. We took the plunge on faith, and I was quite bowled over by the difference between the 16-bit DAT safety copies I had used for editing and the final CDs with HDCD re-dithering. Both are 16 bits, but the re-dithering made a remarkable improvement in both liquidity and detail, making the recording both easier and more rewarding to listen into. Perhaps even moreso on an HDCD player. But I can’t figure out a scientifically valid way to test that!

We were in a bit of a rush to get the Glass Bead Game CD out, and were unsure about whether we could or should use the HDCD mark. We now have resolved that issue. Where we use the Pacific Microsonics box just for re-dithering, as on Rejoice! Volume Three, we note it in the liner notes. Where the Pacific Microsonics box is the A to D, we use the logo, as on our re-mastering (with a new track added) of Ruggiero Ricci’s Paganiniana recital that was previously on Water Lily.