[JamesP81]

I wouldn’t consider myself a stereophile, but I can detect marked difference between the way my music sounds when played on my computer with iTunes and how it sounds coming out of my car CD player from a burned cd. The sound isn’t as rich on car stereo. I haven’t figured out if something is being lost during CD burning, my CDs are of poor quality, the speakers in my car don’t have the audio range that my Bose headphone on my computer has (quite possible), or my CD player doesn’t have the audio range as the sound card in my computer. Or some combination thereof.

[Old Professer]

You can’t tap dance on pillows.

[Lou L]

Your car stereo does have to compete with glass windows and other strangely-shaped surfaces, whereas your home stereo, even your PC, may not.

[joebuck]

Maybe it’s just that your car has bad acoustics and lots of ambient noise. I remember Maximum PC magazine did a blind sound test among several audiophiles and audio hardware reviewers, testing mp3s, turntable records, reel to reel and cassette. Most of the audiophiles said before the tests there is no substitute for a record on a turntable in terms of sound quality. The MP3’s (160 bitrate) won.

[Bloody Sam Roberts]

...the speakers in my car don’t have the audio range that my Bose headphone on my computer has...

Bingo. After having been involved in every phase of the audio electronics business over the years I can say that the weak link is the speakers.

The ones in your vehicle at best, when brand new have a frequency response of 20-20,00Hz. As time and environment does their thing on the rubber surrounds and other elements of the speakers, this reduces their efficiency.

They simply can be no match for the Bose headphones you use where a newer speaker is in close proximity to your ear.

It is possible too that at higher volumes used in a car environment, the amp is clipping a bit (not reproducing higher frequencies) and this would easily affect the sound reproduction. That would depend more on the source and your listening habits.

[Notary Sojac]

Easiest way to test that is to control for the source. Play the same commercial CD in your car and on your computer.

I'm inclined to agree with you that it's the headphones.

Given the same source material, my guess is that most of the variation in perceived quality results from the last link in the chain..whatever you use to produce the final output to your (analog) ears.

[IamConservative]

I haven’t figured out if something is being lost during CD burning, my CDs are of poor quality, the speakers in my car don’t have the audio range that my Bose headphone on my computer has (quite possible), or my CD player doesn’t have the audio range as the sound card in my computer. Or some combination thereof.

May be other factors, but music does lose clarity each time it is digitally transcoded. Multiple points of transcoding is also one of the challenges in VoIP networks. It is hard to put in words the subtle difference - some say tinny, distant, "chambered", etc. - but there is a difference.

[Attention Surplus Disorder]

Without knowing the exact parameters of your A/B test you’re talking about the difference between listening to an mp3 version of a tune versus listening to a “full” WAV file of the same tune. Major difference. The mp3 is in most cases perfectly adequate for headphone or portable use and is an “abbreviated” format designed to conserve disk/memory space. Which it does...at the expected expense of dynamic range and etc etc.

[John Valentine]

...the speakers in my car don’t have the audio range that my Bose headphone on my computer has (quite possible),,,

Ya think?

[RightWhale]

The iTunes files are reduced in spectral range so they will sound reasonably clear in earbuds. When played over a bigger stereo system the difference is audible and definitely not HiFi by older standards. It’s like pop tunes intended to be played over AM radio: HiFi they are not, but you can hear the screeching and caterwauling for a block.

[Hemingway's Ghost]

Seems to me that those cans sitting on your ears (or in them, if they're buds) would sound very different than the speakers in your car, and very different than the speakers in your house. That's probably the chief source of the differences you're hearing.

[HonorInPa]

Your first problem is that music offered on itunes is at a significantly lower bitrate (meaning it has less of the original digital data describing the sound) than a purchased CD. Granted, on most crappy equipment including those tiny earbuds sold with iPods it is nearly impossible to hear a difference. But on good equipment with a ear for music you will definately hear a difference.

You can send higher bitrate music to your iPod but you need much more disk storage.

If you are making cd’S from your iTunes downloads they, too will be at the lower bit rate.

[Neidermeyer]

There is absolutely no difference between an original CD and your burned copy or a iTunes download of the same bitrate 44.1/sec .. the speakers in your car either aren’t up to the job or more likely the road noise is making the sound muddy... digital is digital , a 1 or a 0 , nothing in-between..

[Phantom Lord]

Speakers are one component that clearly there is a major difference in performance. As are sources such as the AV receiver, CD players, amp, pre/pro, etc...

But speaker cables? No.

[Grammy]

Mr G (the audio engineer) says the following “I tunes, preferences, playback, sound enhancer... uncheck sound enhancer. That will make it play music normally.” He said “sound enhancer” is “on” as the default setting and it is a dimension altering affect that is offensive to him (and most audio people).