standard i-tunes, as fitted, which is the way most punters use it.

I don’t use iTunes much, but I have access to a v8.1 installation (which was up to date until recently).

The Import Settings dialog offers the following for converting CDs to compressed format:
– for the AAC encoder it defaults to “iTunes Plus” setting, which it says is 256kbps VBR stereo
– for the MP3 encoder it defaults to 160kbps joint stereo

No wonder the AAC sounds better! Many people can hear compression artifacts in 160kbps joint stereo MP3s, but most won’t hear any such artifacts in 256kbps stereo AAC.

If you have time run a test where you import a CD to MP3 using custom settings = 256kbps VBR normal stereo at highest quality setting. (You may have to tweak the bitrate to get a file of similar size to the AAC, due to the nature of variable bit rate encoding.) Then see if it sounds audibly different from your 256kbps AAC.

It’s not the format alone that determines quality; it’s the format + the encoding settings. If you compare apples to apples you may find much smaller differences (at least with bitrates for high quality reproduction, except perhaps on the margin).

…analogue valve/digital hybrid Pod docks…

IIRC almost all iPod audio docks are not taking digital audio from the iPod interface (at least not the docks that support recent iPods) – they merely give you the iPod analog signal, perhaps with additional processing and amplification. This is because Apple charges significant license fees for access to the digital data over that interface. IIRC Wadia make one that is licensed for access to the digital data, and by now there may be more.

I also have a vague memory of some iPod docs for cars accessing the iPod as a USB disk, which allowed them to get to the files as digital data and decode them outside the iPod. However those devices were vulnerable to changes in the iPod disk structure, meaning they would either stop working or need a firmware update. (Then again, that’s how my copy of MediaMonkey works to sync audio to my iPod, so it seems viable enough – it’s just that it’s easier to update a software version on my PC than firmware on a piece of hardware in a car.)

Other people have modified their iPods to tap in to the digital signal before it goes to the iPod DAC, which is more trouble than I’m willing to go to.

Valves are generally used in amplifiers because some people prefer the sound (or think they are cool). This is typically because they add distortion or modulate the frequency response, but in ways that some people like. You can get essentially the same effect using digital signal processing in front of a decent quality solid state amp. If you read the link about the amplifier challenge, they use an equalizer to compensate for amps with limited frequency response, such as valve amps, when comparing to amps with a full-audio-spectrum response.

Audio spectrum width.

i-tunes as fitted to macs and pcs.

LOL. Then stay tuned and learn ol chap! (grin)

Hey Miglo, that vintage record player pic is an absolute cracker, one that I can easily relate to. I’ll have you know one of the first rock bands of which I was a member used a vintage contraption as such for learning cover songs; it was also used to play Hendrix’ ‘Are You Experienced’ album at band practice, an album which be believe was the first (privately owned) copy of in Australia as it arrived to us via a friend returning from the UK.

On standard setting…

“Standard setting” in what software? They’re all different.

There is a direct relationship between breadth and audio comprehension

You mean by “breadth” the amount of bandwidth used? And do you mean fidelity of musical reproduction, or comprehensibility of spoken/sung words? The latter comes from roughly the 1-5kHz range, not (say) the 15-20kHz range which contributes to the feeling of clarity and (in decent recordings) the sense of space in which the recording was made.

Good luck with your deadline.

1) On standard setting, AAC produces a much better sound quality than a standard MP3.

2) Audio spectrum is the best non-geek guide to sound quality. There is a direct relationship between breadth and audio comprehension.

Yes, I am downloading AAC at a much higher bitrate than the standard.

Hopefully talk to you all … next week

Speaking of two-speakers-enough because concerts are amplified that way, binaural recordings + headphones are rather interesting for realism. They are recorded using a dummy head with microphones in the dummy’s ears, so they record the signal that reaches the ears.

Taken the wrong way, that could lend a whole new meaning to a walk through a mindfield, particularly if the dummy had (induced) boundary issues. And just on the general topic of channels, I thought that this article might interest some…when 3500 channels isn’t enough for super-radiohead.