This encoding system elegantly solves a variety of data-retrieval functions. In EFM encoding, pit and land do not…
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Now that we understand how the playback beam/photo-detector can distinguish between pit and land, let's look at how these distinctions represent digital audio data. One may intuitively think that it would be logical for a pit to represent binary one and a land to represent binary zero, or vice versa. This method would certainly work, but a much more sophisticated scheme has been devised that is fundamental to the CD. It is called Eight-to-Fourteen Modulation, or EFM.
It is apparent that uncorrected data errors are infrequent, and certainly not the cause of sonic degradation from CDs. Consequently, certain products' claims of enhanced musicality through reduced error rates do not stand up under close scrutiny.
The second prevalent misconception about the CD is that if the ones and zeros are the same, the sound must be identical. This tenet is widely held, especially among engineers and computer users. A cornerstone of digital audio theory is that sound quality is independent of the recording or transmission medium. The collective attitude among many…
The jitter measurements that I carried out raised more questions than they answered. As with error rates, none of the devices or treatments reduced jitter in the HF signal. During the testing, I had no idea how much jitter reduction to anticipate, and consequently set the measurement parameters so that even the smallest change would be detected. When I measured no change in jitter, I thought that perhaps the jitter analyzer, or my interpretation of the results, lacked sufficient resolution. However, after completing the jitter measurements, I received the Esoteric PD2, a $4000 CD transport.…
Sidebar 1: Test gear used
This project was made possible by the loan of two pieces of sophisticated test equipment. The first is a CD quality analyzer called the Design Science CD Analyzer, developed by Gordon Rudd in conjunction with Disctronics. It consists of a board that fits in the expansion slot of an IBM-compatible PC, software, and a specially modified Philips CD player. The board takes the HF signal from the player and performs all decoding functions, just like a CD player. Software then analyzes the error types and presents the data in graphic form on the computer display. In…
Sidebar 2: More Measurements
After the above article had been set in type, I saw a fax that Robert Harley had received from AudioPrism. It concerned measurements they had made that seemed to indicate that painting the edge of the CD green with CD Stoplight reduced the amount of noise in the final analog signal. Along with the idea that I gleaned from the Montreux AES Convention—that jitter noise appears as sidebands in the analog signal recovered from CD—this prompted a simple measurement that I thought might reveal such a difference. Using DRA Lab's MLSSA system, I would analyze the…
My name is Wes and I enjoy listening to music on headphones.
Hi Wes!
I guess it all started when I was a kid—I'd go to bed and tune my radio to faraway stations. That's where I first heard real R&B, Chicago-style blues, and hard-core honky-tonk. It was comforting listening alone in the dark and, well, sometimes I'd get really excited.
Such as the first time I heard Howlin' Wolf. Nothing in my white-bread upbringing had prepared me for that, let me tell you. I didn't know what to make of it, but somehow I just knew there had to be more where that came from—and I knew I…
Head Games
Tyll was an audiophile with a real he-man hi-fi who one day realized that he was hardly ever at home to enjoy it. Glancing around the airport terminal that proved to be his personal road to Tarsus, Tyll noticed how many people were wearing cheap'n'crappy headsets attached to personal stereos. Hey! he thought. What if all that time people spend listening to music on the go could be turned into a high-quality listening experience? Thus was planted the seed that grew into HeadRoom—these days, the company offers mail-order convenience for a variety of headphone amplifier/…
Tyll was an audiophile with a real he-man hi-fi who one day realized that he was hardly ever at home to enjoy it. Glancing around the airport terminal that proved to be his personal road to Tarsus, Tyll noticed how many people were wearing cheap'n'crappy headsets attached to personal stereos. Hey! he thought. What if all that time people spend listening to music on the go could be turned into a high-quality listening experience? Thus was planted the seed that grew into HeadRoom—these days, the company offers mail-order convenience for a variety of headphone amplifier/…
Head of the Class
Articulate—that's the word that best describes Max. Oh, there are others: fast, rich, complex—and, paradoxically, simple as well. But articulate is the one that resonates most strongly. Perhaps I'm more sensitive to this than most, but for me, music is primarily about communication.
Articulate—that's the word that best describes Max. Oh, there are others: fast, rich, complex—and, paradoxically, simple as well. But articulate is the one that resonates most strongly. Perhaps I'm more sensitive to this than most, but for me, music is primarily about communication.
It could be argued that musical communication is compromised when the complete frequency range is slighted, or when transient edges are blunted—and I agree entirely. In fact, HeadRoom Max illuminates the frequency extremes with uncommon clarity. Its bass response is deep and full-bodied…
Listening through Max, I was intensely aware that both sets of voices—despite their seeming solidity—are not themselves physical entities, although they define that which contains them. You can hear through them—almost see through them—and when someone nudges a hymnal with their foot (at least that's what it sounds like to me), the scrape of the cover along the stone floor and the reverberations from that motion are startling in the way in which they define a specific point within all of that space.
Ultimately, however, I must keep returning to that least definable of qualities, but the…
Sidebar 1: Specifications
Description: Headphone amplifier with one set of inputs, one set of feedthrough outputs, two sets of headphone outputs. Power rating: 0.5W. Frequency response, THD, Crosstalk, S/N ratio: all not specified.
Dimensions: 6.7" W by 2.4" H by 12" D.
Serial number of unit reviewed: None on review sample.
Price: $1333. Approximate number of dealers: sold factory-direct only.
Manufacturer: HeadRoom Corp., P.O. Box 6549, Bozeman, MT 59715. Tel: (800) 828-8184, (406) 587-9466. Fax: (406) 587-9484. Web: www.headphone.com .