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Positive Feedback ISSUE 8
as reviewed by Danny Kaey
This review has been a long time comingten years! It was about ten years ago that I realized that the future of audio in general, and to some extent the high end industry, would be in on-demand music and entertainment. This was way before the internet took off, before multi-stack hard drives with capacities of the order of 250 gigabytes, before Athlon/Opteron 64s, etc. My realization took form when Sony introduced the MiniDisc. The idea was simplemake your music personal and portable, more so than already-existing portable CD players, by reducing the size of the disc itself. As it so often goes with technology, a benefit entails a loss, and in this case it was sound quality, though that didn't seem to be much of a problem, as its intended use was the go-fast, go-anywhere portable player.
Radical measures had to be taken in order to fit a CD's worth of data on a disc that was about half the size. One option was to shrink the laser, but technology back then (this was ten years ago!) was not quite up to speed on this, and a more intuitive method had to be utilized. Taking advantage of recent studies in psychoacoustics, clever engineers figured out that if you hear two simultaneous sounds, one louder than the other, the louder sound will mask the softer one, and the first compression algorithm was born. Why bother recording something when you won't hear it? "Normal" recording processes, such as the red book CD standard, encode ALL signals, regardless of fidelity. While this compression scheme would work wonders in a perfect world, the reality of the matter is somewhat different. Utilizing a standard 10:1 compression standard, which reduces the size of a song that would normally take up, say, 50 megabytes, the results are nothing short of amazinga mere 5 megabytes of space is taken up! The problem is that with a "standard" amount of compression, musical fidelity is pretty much down the toilet as well.
Sony had a nice idea in theory, but in practice, the fact that you still had to carry the discs, not to mention a fairly bulky piece of equipment (by comparison, Sony cassette players were scarcely larger than the cassettes themselves), meant that cassettes were still the norm for personalized, take-anywhere music. Nevertheless, the MiniDisc was a pivotal development in the coming digital revolution. As with the MiniDisc, size, specifically hard disc size, played a major role in the continuous development and foundation for mp3 playback. Here again, the idea was a simple oneutilizing your computer, you could play all of your favorite music and not have to bother switching CDs. Playlists (collections of music that the software would play on cue) became the rage. Nullsoft's Winamp and the doomed but ironically soon-to-be-resurrected Napster are the heros of this age of compressed fidelity. As soon as the internet became the de facto means of communication, it didn't take long for people to start swapping songs. It is ironic that Apple, a company that was really late to the game of computer music storage, is now the undisputed leader of on-demand music service. Grab your favorite CD, open up Apple's amazing software, iTunes, rip the songs, store them on your hard drive, and play them over a network that takes advantage of yet another Apple milestone, Rendezvous. Or, in this case, transfer tunes to your iPod, and voila, you have music everywhere, anytime, and most of all, hassle free!
Hence I am reviewing Apple's iPod. PFO is a webzine for the higher fidelity crowd, so why would we care about an inherently lossy format? The answer, my friends, is that this will be the new way. Give it a few more years, and I bet you that respected audio manufacturers will cling to this new mode of delivering music to your ears, in high end sound, with no compression, and with instant access to your now-digitized music library. Of course, I'll still have my recently acquired Transrotor Fat Bob, and will still very much enjoy playing the "records" that my ten-year-old daughter considers very uncool.
The iPod is a relatively small, hard-disc-based storage device, about the size of a compact cassette. Apple really shines in its industrial design, and the iPod is no exception. Even the packaging the player comes in is absolutely astonishing! There are three different versions of the iPod, all exactly the same except for the size of the hard drive10, 15, and 30 gigabytes are available. My review iPod is the 15-gig model, retailing for $399, which includes a set of headphones, remote control, carrying pouch, and of course a charger. You can get lesser models from other vendors for somewhat less money, and while bargain shoppers might be attracted to the lower price of the competitive devices, none come even close to the iPod in terms of performance, looks, features, and quality. Spend the extra money and get the original. (Note that the least expensive iPod goes for $299.) By the way, this iPod is second generation, which has shown great levels of progress compared to the first.
Unpack your new toy, install the accompanied software, plug the iPod into your computer via the supplied, ultra-fast-bandwidth Firewire 1394 interface, and you are ready to reap the joys of music on demand. Apple will soon release a specially written, Windows-compatible version of its proprietary software, iTunes, along with access to the music store. For now, Windows users are stuck with the okay (as in, gets the job done) music management software, Musicmatch 7.5. The iPod understands two music formats, AAC and mp3. AAC is an Apple-only codec, while mp3 is more popular. In defiance of Microsoft's own version of on-demand music, Windows Media Format, Windows users cannot utilize any tracks encoded through Windows Media Player 9. This does two things. First, it makes my life easier, as I only have to play with mp3 files. Second, it means that all users who have stored their CD libraries in WMA have to reconvert them or rip them into the mp3 format.
Having fully charged the player and synced it with my audio library, I was ready to tackle this review. To connect the iPod to your system, you will need to get a pair of mini-headphone-jack-to-RCA cables. Several are available, and as of this writing my good friends at Audio Magic are crafting me a special version of their award-winning cables. This review is based on three different mp3 algorithms; encoding at 128kps (kilobites per second) and 256kps. We have two audio formats at opposite ends of the sound quality spectrum: ultra-high-resolution SACD vs. ultra-compact mp3/WMA/AAC encoding. Am I going to compare the iPod to SACD players? No, of course not. That's not the point, though I can clearly see devices such as this eventually playing ultra-high-res audio formats.
Some years ago, a German audio group conducted a study on the audio performance of compression standards and how they stack up to CDs and LPs. Surprisingly (though not to me), the group found that nine out of ten participants could not distinguish the mp3 version of a particular song to the 16-bit red book CD standard, nor did they prefer the overall sound of vinyl to mp3. The funny thing is that virtually ALL of my friends who come over to my house to listen can easily distinguish mp3 sound from CD or LP (though vinyl gives itself away through pops and such). Presumably, my friends are no different from the people who participated in the German study, so I find the results of the trial somewhat difficult to believe. It is a foregone conclusion that the iPod will not sound as good as your average CD player, much less your high end player or vinyl playback equipment. My mission was to find out exactly how much fidelity the iPod will lose. To that effect, I took a good mixture of pop, rock, jazz, and classics into my listening room.
I figured that the music typically played by such devices, and that would give it the best possible scenario to shine, is pop and rock, in which the audible side effects of heavy compression are least noticeable. Comparing my favorite Massive Attack CD, Protection, on the Cary 308T CD player and on the iPod encoded at 128kps, the results were as expected. This CD is very well recorded, with wide dynamics, a large soundstage, nicely extended highs, and a bass line that will test anyone's playback system. Track 3, "Three," on the Cary, sounded as it should. From the opening keyboard effects to the spot where the bass line kicks in, everything was thereair, space, soundstage, and an effortless transition into the subtle bass line. Tones had a natural attack and decay. Bass was tight. When Tracey Thorn started to sing, her voice sounded clear, yet very subtle, transcendent, and soft. I am sure that the recording engineer used all sorts of gimmickscompressors, limiters, etc.to get the effects they were looking for, but the point is that the song sounded awesome through the Cary.
On the iPod at 128kps, the soundstage was washed out and had lost that tightly defined space. Instead of the keyboards sounding focused, they were just out there, kind of like someone tossed the information into space. The bass line that came into play so subtly through the Cary now lagged in rhythm and pace. This is the typical compression scenario. The attack of a note seems to lag behind the natural sound curve while the note is sustained and then goes through decay. The effects, though small, are immediately noticeable. Even my wife, truly a non-audiophile, was able to hear the difference. The effects are reminiscent of Dolby C and to DBX, where you could notice the filters kicking in and producing the audible "pumping" effect. Dolby B, while less effective than either C or DBX, proved to be the more musical noise reduction format because it utilized much less compression than either of the two other formats. Could the same hold true for mp3 playback?
I cued up the same tracks again, this time upping the iPod's throughput to 256kps, the highest level at which I would ever realistically encode, since the file size goes up almost 50% as well. Apple's marketing claims for more than 7000 songs on your iPod depends mostly on file size, and you could end up with half that if you reduce the compression effect. AT 256 kps, the same Massive Attack track flowed effortlessly. This is one of those tracks that I can listen to over and over without any fatigue. Playing it on a full-range system really gets my mind off things, as I succumb to the powerful effect of its dark rhythm. Listening to it on the iPod at 256kps was quite the experience. In the opening scene, the keyboards draw your attention. Here, the biggest difference between the 256 and the 128 kps version was that on the 256 kps version, the air, space, and aura of the track was almost as good as on the CD. No longer did I feel as if the tones were thrown in at random. Rather, there was order in the time-space continuum. As the first bass line sample kicked in, the lagging attack noted in the 128 kps version was only faintly noticeable. The bass line had no hint of compression. Tracey Thorn's vocals gave the only evidence of a touch of grain, and I really had to concentrate to hear it. On the CD, her voice has a soft-spoken, meditative soundno doubt heavily processed, yet very enjoyable, almost like a goodnight poem you say to your loved one. The iPod captured much, if not all of this atmosphere.
This experience was essentially duplicated on virtually my entire pop music collection of music. In some cases, the effects of compression were audible even in 256kps, yet in other instances, the effects were almost nonexistent. Take this with a grain of salt. By no means am I saying that you should go out and convert all your music to 256kps mp3 format. Your mileage will vary depending on the material, and of course your playback equipment.
Hugh Masekela's Hope is my other long term test disc. Recorded live a few years back, it showcases the awesome sound quality one can obtain from a live performance if all the ducks are in a row. Masekela's voice is amazing, and the power of the track simply needs to be heard. The track is very dynamic, very wide in soundstage, and proved to be quite the treacherous test of mp3's compression scheme. The Cary played this track in all its glory, with the feeling of the band playing in front of you, including clearly defined spaces between the instruments, and of course depth. Masekela's voice was solid, focused, and authoritative as he narrated the lives of African diamond miners working for oppressive employers for next to nothing. I then cued up the iPod in 128kps and listened. Eeeeeek!!! This was plain old nasty! Everything collapsedthe soundstage, the space between the performers, the immediacy of the voice, all shrank and became ambiguous and rather flat sounding. The dynamics were somewhat intact, but if you take the icing off the cake, something is missing, no matter how good the cake. Masakela's raspy voice wasn't focused, andas with the Massive Attack trackclouds covered the performers. The compression effects were definitely more noticeable on this track. I presume it has to do with both the amount and the type of information being transcodedthe more complex the information, the harder the filters have to work, and the more errors start to creep in, degrading performance. In 256kps encoding, a startling difference presented itself. It was as though someone magically brought focus and tightness to the performance. Instruments were suddenly brought in the right place and time, pace and rhythm were there, much like in the CD. The detrimental effects were still noticeable, but much less so than in the 128kps encoding process.
Trying to learn more about these effects, I started pulling material from different genres. The effects ranged from hardly noticeable to, in some cases, awful and harsh sounding, like early digital in, say, the mid 80s. To keep perspective, let's not forget the intended use of this format. Playing these tracks through the iPod's supplied headphones on the iPod proved that you could encode entire catalogs in 128kps and not really notice much difference in quality. While sound quality is of the utmost concern for audiophiles, the overriding concerns for most people are accessibility, portability, and ease of use. In all those areas, the iPod literally shines. Portability? It's the size of a deck of cards. Accessibility? How about access to hundreds of albums and songs at the touch of a button? Indeed, here is where I am most happy to report that Apple engineers did an outstanding job. There is a nice-sized black/white LCD readout display. The operating system of the iPod is cleverly devised, and can be easily updated. Accessing all of the features of the iPod is done through a nice round scroll pad, with the aid of five buttons. The LCD lists such amenities such as album name, track name, all supported forms of time (remaining, elapsed, etc), and among other neat features, a calendar function is also built in. Compare this to any CD player out there and you will see what I mean.
Going back to the initial point I was trying to make, even those in audiophile circles must see the immediate benefit of such a system. Imagine for a minute being able to download, save, copy, OWN (!), and play back ultra-high resolution material onto a small device that can be plugged into your home audio system, and being able to enjoy thousands of hours of music at the touch of a button. Not too long ago, I was having dinner with a few friends, all of them audio buffs, and the topic of the iPod came up. While most said they wouldn't really care about the means of music delivery, so long as it sounded good, some were somewhat averse to the idea of substituting something like the iPod for their coveted CDs. I for one am very impressed with the iPod, and am certain that improvements will follow in due time. This little thing does what it was designed to do superbly, and even under the most strenuous of situations, you will find the sound to be quite good. Okay, it's not a replacement for your CD player, and depending on recording resolution, your mileage will vary.
One item of particular importance that I wanted to mention is the growing number of requests from consumers of mainstream publications (TAS, Stereophile, etc.) to get in on this subject. Sure, there are several camps. On one side we have people asking for evaluations of music available at Apple's online Music Store (where all music is encoded in the 128kps format, and you cannot choose higher-quality downloads). The other side is increasingly asking for audiophile companies to enter the arena of hard-disc-based storage systems. I am a firm believer that some type of uncompressed data storage, along with cleverly designed and implemented control software, will lead the way to a new generation of music players. Danny Kaey