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Essay - "The Changing Face of Home Entertainment: Our Digital Future" - June, 1997

By Colin Miller

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As more and more of us put CD players in our cars, we find ourselves with another possible way that an accident can happen while driving, e.g., trying to open the jewel case with one hand. Taking our eyes off the road is a bad idea, so what are we to do with the ever-increasing complexity of our automobile hi-fis? A tape cassette poses the same limited storage as CDs, and with inferior sound quality. FM reception in a car from most major broadcasters is usually both unpredictable and far from stellar, although far superior to AM, which is, in my opinion, a waste of bandwidth for anything except for the news or event coverage that's usually pretty inane anyway. A multiple CD changer provides longer possible playback, and relieves the vehicle operator of the potentially dangerous sequence of maneuvers inherent to loading our delicate aluminum or gold platters. Tragically, it also limits our freedom to spontaneously play that favorite piece that we forgot to load into the trunk. What kind of device would provide convenient storage and playback without requiring a jukebox style rack of magazines and trays?

My roommate suggested MIDI files with a computer in the car for playback since many popular recordings these days either use synthesizers or samples anyway. Not a bad idea, but it would have to contain some relatively sophisticated hardware, and standardization of MIDI files would be a pain. But consider this: Imagine a product that could load CDs, or even DVDs, store certain pieces into memory to recall at any possible later time, and play any of them back on the fly with absolutely no loss in sound quality. Seem like a nifty idea? It's already happened, sort of, and it is VERY nifty.

The nice thing about having friends in the recording and computer industry is learning new ways to play with toys you already know and love. Such is my case. My roommate treats his computer like I treat my stereo. "I could put this in, load this, run that . . . sell the whole thing and get a quad-processor, blah blah blah . . ." It makes me appreciate my girlfriend's patience when I realize what it must be like to listen to me go on about output impedances, voltage drops, shunting Zobel networks, and every fascinating aspect I can glean from audio newsgroups, mailing lists, or my written-for-idiots electronics textbook. Andor Izsak, my link to professional recording hardware and methods, also indulges heavily in the swiftly changing sector of computer baubles. He pointed out the method of playback on his home collection of electronics and transducers which coincidentally sounded pretty darn good. His PC, outfitted with a sound card equipped with a digital output, fed his Counterpoint DA-10 D/A converter armed with the anti-jitter JAC-Card complete with HDCD. This setup will not accommodate the automobile, as the hard drive doesn't react well to potholes, but it does provide some genuinely useful features. Computers tend to be modular, and hence upgradeable. Hardware, as well as software, can be swapped out at the individual's, or perhaps more likely the individual's budget's convenience. Features abound for the choosing, and open an entirely new arena of customization for the consumer. Now this isn't new, but until recently it wasn't very viable to high performance audio within mortal pocketbooks.

Any computer that has a CD-ROM installed can play a CD. Any computer with some kind of recording software can store that information in whatever files it likes, and play it back. On-board computer sound cards have also come a long way, and some sound reasonably good. When I say reasonably good, I mean that it works, and it's not annoying, but it's not even close to anything acceptable as a reference, let alone a portal to fantasia. Computers are very noisy, and not just because of the cooling fans. Electrical noise inside of a computer is horrendous. That's not a disaster for data transfer, but for an analog audio signal, it's unavoidable contamination. It might seem that I am contradicting myself, especially after I stressed how well Andor's computer relayed the information through his own system. If you say to yourself, "No, not really," then you're already ahead of me.

Andor uses an outboard DAC, or digital to analog converter, removed from the RF and EMI mess by two Hungarian body lengths space, the shielding of two steel cases, plus an anti-jitter filter to compensate for timing errors. Thus, the much heartier digital signal, assuming sufficient bandwidth in the 75 Ohm coaxial cable, remains essentially a perfect conveyance of the data stored onto the hard drive. Don't scream at me, "You're one of those Perfect Sound Forever" people. The information will not improve on its fixed level of resolution, nor will the recording get any better. That said, sure, ok, it works, but it may seem like overkill to replace a $300 CD player fitted with a digital output for a computer which costs a couple of thousand or so? Maybe, but isn't overkill a staple of high-end audio? How much do simple high-end transports cost these days anyway? One can abscond with Enlightened Audio Design's 2000-T, one of the better transport units I've had the fortune to play with, in exchange for a paltry $2,500. Levinson offers their unit for about $11,000 or so, and I assume that somebody must buy them or why would they make them? If you have an output with a stable clock, a decent digital cable (video cables with megahertz bandwidth work quite well), and a nicely designed D/A converter, a computer makes astounding sense.

Most manufacturers in the consumer market might find this idea (PC for music) repugnant. I don't think that many will jump at the idea of using a PC for playing source material. It gives the consumer too much freedom to pick and choose between different manufacturers. On the other hand, computerized components do seem to be gaining acceptance. If you doubt, check out some of the latest offerings from Classe, B&K, Citation, Meridian, Theta, Enlightened Audio Design, and so on. They're computers that specialize in taking in digital information, processing it, and sending it on its way to the appropriate channel of amplification via the complementary analog section. I believe that this is the future of high-end preamps: analog sections to accommodate the lover of vintage software, with digital processors and D/A converters built in to deliver the shortest possible path to the power amplifier for the purist. There are some active linestage preamps that simply switch, provide gain, and attenuate, which sound pretty good. However, they usually begin to sound somewhat acceptable at $1,000 if you buy your equipment new, and I personally can't justify paying that much for what a fifty dollar potentiometer and a Radio Shack rotary switch mounted in a plastic lunch box can do better. In my opinion, if it's active, it better do something. I am, of course, making the sweeping assumption that accurate playback, or at least playback altered by intentional (vs. unintentional) processes, is indeed the end goal. If this is the case, then using a computer to store and playback source material isn't such a ridiculous course to follow. After all, there are some real advantages to this mode of transportation.

When you consider all the extra capabilities possible, it appears downright logical. Besides downloading your e-mail, typing your résumé, or hacking down bloodthirsty demons who rudely keep poking your pixelized hero with sharp pointy things, a computer could then put you in the mood for relaxing and audible compression waves. In addition, one can edit and massage a favorite recordings in a controlled and predictable manner, giving the audiophile the freedom to alter the sound without swapping cables, changing tubes, listening upside down, or whacking themselves with heavy mystery objects. Take those digitally enslaved vintage analog recordings that were poorly mastered for the change of environment, equalize, reverb them a bit, apply noise reduction, or even Q-sound effects if you like. One can tailor the source material where it makes the most sense, at the source. Instead of using a few generic DSPs that came with a surround processor, the consumer can tailor the music to his or her own taste, with capabilities limited only by interchangeable software.

Understand, I like my tweaks too. Jack Bybee's little power purifier boxes have done pretty well by me, but if a specific recording lacks reverberation or warmth, why not edit it in the digital domain and give it just that and only that? It may not be higher fidelity, but it will be more of what you want. Besides, if the algorithms are right, it should be much cleaner than any affordable analog processors, more effective than weirdo spiritual discs, and less effort than moving diffusion panels to different positions for every track. If good analog equalizers have a place in your system, keep them around for compensating for relatively fixed variables, like room acoustics or speaker response.

Even if you're a "purist" who doesn't want to meddle with the whole shabby process, once you load your CDs to read and store on the computer, they can go safely on a shelf, minimizing their scratch risk. Come to think of it, you might even be able to download your music, and not use CDs at all. Internet shopping is gaining popularity. Download onto a big hard drive, and when the compilation grows big enough, burn a DVD. That's another issue where a computer excels. When DVD kicks in full gear, you don't have to trash your laserdisc player. Install a DVD drive, install the software, and you're alive on the cutting edge! Should something else come along, you'll have only a similar process to contend with. If you own a personal computer, you know that pretty much everything is upgradeable to a point, and if it's not, you'd probably have to buy a new computer to run your other applications anyway. Computers are simply the tools of our era when it comes to storing and implementing information. Can a whirring computer drive contend with a true high-end transport? I don't know that it can, right now, but there's always the near future to make it work.

All CD transports are not the same. Sonic differences between transports do exist, though the amount usually depends on the D/A converter. Andor's DA-10 didn't seem to care all that much what was plugged into it. When we compared identical digital files played from an older Denon CD player and from his computer, I couldn't hear any clear differences. At least those differences were not significant in that environment. Again, his Counterpoint DA-10 contained the anti-jitter option, and the noise floor wasn't as low as I'd have liked it. Maybe there were small electronic differences we couldn't detect with our ears. Even so, transport mechanisms are surprisingly similar. No matter who made your CD player or transport, chances are that Philips, Sony, Pioneer, Teac, etc., had a piece of the manufacturing process. My NEC CD-ROM seven disc changer looks and operates suspiciously like a Nakamichi Music Bank. Is it the same? No. Does it have some of the same parts? More than likely. The mechanical parts turn your disc, read the data, and spit it into the RAM buffer. So long as it's tracking as the servo directs it, and there's no data loss, you can't ask anymore from the mechanical side. From the RAM buffer on, excellence in design and construction pays off.

Even though a PC can transfer data many times faster than your home CD player/transport, the quality of that data transfer depends on the master clock that sets the sample rate on playback. If not perfect, it induces jitter. Jitter can introduce sonic artifacts if allowed beyond significant levels. In addition, any limitation in bandwidth from the output stage will round off the square waves that transmit this information, causing ambiguous timing at the receiving end. More jitter, less fidelity. Electronics are not perfect, but good electronics are better than poor electronics (you can quote me on that). In order to perform at the same level as the consumer transport counterpart, the digital output card in the computer must be manufactured and designed with the same attention to power supply regulation, master clock reliability, output devices, and component quality. This most likely means a separate power supply, and no Toslink. LEDs look nice on some faceplates, but there's no reason to use a bandwidth funnel for digital transmission. Besides, if a 75 Ohm coaxial cable can handle all of your television stations, it's probably more than adequate for two, five, or even ten channels of audio.

If somehow PC playback took off, you might see a Wadia soundcard. Well, maybe not, but it'd probably be pretty cool. They're an innovative bunch, and aside from digital concerns, there are some other issues that might prove problematic. One that comes to mind is the cooling fan. I have computers at home. Five of them to be precise. If they're all on, and the doors are open, it sounds like a B-52 in my office (a 266 MHz Pentium II has TWO fans). Certainly too loud for serious listening. This would have to be addressed. Perhaps a remote screen, keyboard, and mouse would allow placing a computer in another room, or someone will design a case with much quieter fans and hard disks. I hope so.

Another problem is storage space. A CD can hold up to 640 megabytes of information. Four CDs will require more than 2 gigabytes. But storage capacity is increasing, and decreasing in price. In 1991, a 200 MB hard drive cost somewhere around $900. Now, you might be able to get one for $300. I've heard rumors of 40 gigabyte (GB) hard drives available for about $2,000, so there's hope. Even with 4 gigs, that's still enough music for an evening, and usually people don't listen to the entire disc anyway. I usually have a few favorites that I return to, and at least a couple I avoid on every album. Recently, a 1 GB memory chip was announced as forthcoming. Soon, hard disk drives will not even be necessary. How does 10 GB of memory chips in your car hi-fi sound to you? That'll certainly hold enough music to get me to the post office and back. All eyes on the road too. Accident insurance will go down in price to make up for the cost of the chips.

Even if it does become feasible, I don't think anyone is going to invest a bunch of resources into developing audiophile digital sound cards quite yet. If it happens later (hope, hope), I'd certainly join in just because it would mean two things: One, my computer would probably be quieter, and two, I could easily alter all the bad music recordings I love. For those two reasons alone, even though I don't think anybody will develop technologies in that direction by Christmas 1997, especially Wadia, perhaps somebody should. What could be better than complete control, especially with an "undo" function on a big fat tool bar?

Colin Miller


© Copyright 1997, Secrets of Home Theater & High Fidelity
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