[gilfish]

I just did some comparisons of music played back through my Macbook Pro, AIFF files through iTunes version 7.6 compared to the original CD. The iTunes sound had accentuated bass and other characteristics that were distinctly worse than the original CD. I have the equalizer and sound enhancement stuff turned off. Then I played the same file back in Quicktime 7.41, the sound was nearly identical to the CD.

I was able to do the comparison using a Trends Audio USB DAC into my APL Denon 3910 with a digital input. I am able to start both the CD and the computer audio file at the same time and switch back and forth to clearly hear the differences.

Has anyone else experienced these differences between iTunes and Quicktime playback?

 

[poo]

Strange because iTunes uses Quicktime settings...

 

[Shoreman]

Quote:

Originally Posted by poo /img/forum/go_quote.gif Strange because iTunes uses Quicktime settings...

I was gonna say the same thing. But I did play a couple of audio files that I'm quite familiar with directly through QT (had never done so before) and, I must admit, they did sound surprisingly good at first blush. More "foobar-like" than iTunes. This was just a quick listen, but I'm gonna do some more experimenting this morning. If indeed there is a difference, boy I'd love to hear the technical explanation, given the operating premise that the Quicktime engine is doing the processing in both cases, irrespective of the front end.

 

[Shoreman]

Quote:

Originally Posted by Shoreman /img/forum/go_quote.gif I was gonna say the same thing. But I did play a couple of audio files that I'm quite familiar with directly through QT (had never done so before) and, I must admit, they did sound surprisingly good at first blush. More "foobar-like" than iTunes. This was just a quick listen, but I'm gonna do some more experimenting this morning. If indeed there is a difference, boy I'd love to hear the technical explanation, given the operating premise that the Quicktime engine is doing the processing in both cases, irrespective of the front end.

Nah...after further (albeit subjective) review with more audio files, I conclude that there's no difference between the two. At least to these ears. Nor, as implied in the two previous posts, should there be.

 

[Bizzel]

Is iTunes applying volume leveling? QuickTime wouldn't do that on its own.

 

[gilfish]

In my tests, there is clearly a difference between a track played back in iTunes compared to the original CD and a track played back in Quicktime compared to the CD. The Quicktime playback sounds much closer - if not identical - to the original source (CD) and iTunes accentuates the bass and adds something else to the sound that I can't put my finger on. i will do more testing, but the difference is NOT subtle. I would bet anyone can distinguish the two sounding different.

Who knows what the reason for this is, but I will do further testing and try to pinpoint the differences I hear. I will try to determine if this only occurs on all file types or only certain ones (aiff and Apple Lossless).

 

[Wodgy]

What you're hearing is placebo. On Macs, iTunes is bit-perfect, provided you don't have the equalizer or "sound check" on.

Don't take my word for it. You can test this yourself provided you have the right equipment. Do a search. Many have done it. I've done it.

 

[sparky22]

You might want to double check your settings.
Followiing the Stereophile review of the Benchmark DAC, some interesting results were found. Details are posted on the Benchmark Wiki.
ITunes-QuickTime for Mac - Setup Guide - Benchmark

Sparky22

 

[bigshot]

Also check to see if sound enhancer is checked on.

See ya
Steve

 

[shigzeo]

if you really want to check, you can turn off all sound enhancements and get the same song to play from both and you turn away from the computer while a friend checks you. s/he will randomly play the songs and you will guess which player is playing the song. do this for a finite number of times, i suggest about 14 or 20 (an even number). if you can do this test 3x and get a lopsided result, then well, maybe there is a difference, but that result must be very lopsided and you must perform this test many times.

it probably is placebo but it may not be.

 

[majid]

The most important part is to change your digital output's sample rate to 44.1kHz. If it's set to 48kHz, you will experience distortion from sample rate conversio, but that would hit both iTunes and Quicktime.

The 48kHz frequency was precisely choses by the DAT standards group under pressure from the music industry because the required SRC would degrade CD quality, as they were afraid DAT would cause widespread piracy. Why does that seem familiar?

 

[Happy Camper]

set up itunes to use the foobar player.

 

[gilfish]

I just figured out why the sound was different. I turned off the sound check, sound enhancer, but forgot to turn off the damn equalizer. Oops

That would explain why they sound different!

Now that I figured out the main difference, I will continue to compare the sound of a CD-based music (via the Trends Audio USB converter to my DAC) compared to a CD.

Thanks for all your feedback on this.

 

[krmathis]

He he
That explains it!