SAN FRANCISCO - Music lovers remember a familiar advertising image from the past: a man reclined in a chair, head back, blown away by music from his high-fidelity sound system.

Like the Marlboro Man before him, Maxell's pitchman is now a relic.

With their ability to store vast libraries of music in your pocket, sleek digital music players have replaced bulky home stereo systems as the music gear of choice. But the sound quality of digital audio files is noticeably inferior to that of compact discs and even vinyl.

Are these the final days of hi-fi sound? Judging by the two billion songs downloaded from Apple Inc.'s iTunes service, the ubiquity of white iPod "ear buds,'' and the hundreds of thousands of folks file-sharing for free, the answer is yes.

"In many ways, good enough (sound quality) is fine,'' said Paul Connolly, an art installation specialist and longtime audiophile from Sugar Land, Texas, who's now in the process of digitizing his 2,400 CD collection in Apple's lossless digital audio format.

"The warmth and the nice distortion that the album had was beautiful,'' he said. "But do I long for the days of albums? No. Do I long for the days of CDs now that we've gone digital? No. It's a medium.''

Justin Schoenmoser, of San Francisco, also traded in his rack system for an iPod. Currently working abroad and toting along his iPod, the convenience of carrying thousands of songs in a gadget smaller than a pack of cigarettes outweighs the sacrifice of quality.

"The last time I had a full-blown home stereo system was in the mid-'90s, and it was a gift from my parents,'' Schoenmoser said. "As I converted most of my stuff to digital over the last five years, I finally got rid of all my old equipment.''

A song ripped from a CD at 128 kilobits per second -- the default setting for most software -- retains only a fraction of the audio data contained on the originally mastered disc. Whether you downloaded the track from ITunes or copped it off LimeWire, the song remains the same. The small digital music file is a highly compressed shadow of the originally mastered recording.

And regardless of how advanced your home audio setup is, if you're pumping a low-rate MP3 or ITunes file into it, you're getting a low-rate rendition of the original song out of it. It's listenable, but still lacking the lustre of a CD played on the same system.

Some experts say the sound quality lost in the process is undetectable to most untrained ears. But Michael Silver can hear the difference.

Audio High, his high-end stereo shop in Mountain View, sells things like a US$5,000 needle for your turntable and stereo cable at $2,700 a metre.

"It doesn't compare,'' Silver said of the sound quality offered by today's portable digital music players and their compressed audio files.

If his high-end gear is like a Ferrari for sound, and run-of-the-mill stereo equipment is a Honda, "a moped is an iPod,'' Silver said.

That difference in sound quality, perceptible or not, hasn't saved some of the bigger traditional stereo and music sellers.

Tweeter Home Entertainment Group Inc., a Canton, Mass.-based retailer of mid-to-high end audio equipment, is closing 49 of its 153 U.S. stores. Slumping sales at Sacramento, Calif.-based Tower Records led that former industry juggernaut to declare Chapter 11 bankruptcy protection in August.

And Circuit City, the No. 2 electronics retailer in the U.S., is laying off 3,400 of its most experienced clerks.

Year-to-date data from a recent Nielsen SoundScan report shows sales of prerecorded CDs in the United States down 20 per cent from last year.

"Everybody has a certain amount of money to spend. It's not that they're choosing not to spend it on the old-style audio. It's that something new came along,'' said James McQuivey, principle analyst for media technology at Forrester Research Inc.

"The MP3 player integrated the collection of the music with the playback of the music,'' he said. "Now all of it's seamlessley hidden away on a hard drive somewhere.''

With the networked household ready to fill the void left by the demise of rack stereo systems, McQuivey sees a steady stream of new devices on the horizon that will erase any lingering drawbacks to going all-MP3.

Santa Barbara-based Sonos Inc., for example, sells a system that allows you to use a handheld device to navigate streamed music from your PC to an existing amp and speaker or home theatre setup, sort of a hybrid between the old guard and the new.

"A CD is not relevant to me anymore,'' said John MacFarlane, founder and chief executive of Sonos. "The iPod and that type of portable music player has even accelerated that trend.''

Even when consumers do buy CDs these days, "the first thing you do is rip your CDs and put them on your iPods,'' MacFarlane said.

MacFarlane isn't even convinced that casual listeners can hear the difference between CD-quality sounds and the dumbed-down MP3 files, which he calls "good quality, not perfect.''

"When Philips and Sony first made the CD, they didn't cut any corners because they were careful to preserve everything that was there, even if you couldn't hear it,'' MacFarlane said. "That 128 is pretty darn good. A lot of PhDs went in to making that 128 kbps work well and sound well.

Schoenmoser, the globetrotting Californian, agrees.

"I honestly can't really tell the difference between CD, tape and digital,'' he said. "I'd even accept a lower quality as long as it's digital and portable.''