IPod 160GB - the good and the bad new

Question

I received my iPod 160GB this morning. Here are some of my first impressions.
The good news:
I was a bit worried about speed issues and/or crashing as posted on this forum, but my iPod seems to work without any major speed issues, and I haven't encountered any crash so-far. The content is about 60GB of music, lots of covers, 2 movies, agenda and contacts. Even cover flow has a very acceptable speed (faster than on my dual G5 PowerMac), though I wonder its suitability with an amount of covers associated with 160GB of music. The only performance issue I encounter when I go back to the main menu, where arbitrary cover art is shown using Ken Burn effects. I guess a bit of caching can solve this issue.
The bad news:
Sound quality. The good thing is that it's more crisp than the iPod Video 5G 60GB (more loudness > 8kHz) adding to a pronunced sort of accuracy with cymbals and percussion beats, but a bit too crisp from a timbre standpoint of view (reminds me a bit of my iPod 3G). It also has less energy in the lower mid-range (200-800Hz), so it misses some push and harmonics. Overall this results in a less harmonic sound, less spatial (the scene is inside your head instead of around your head), a bit too much emphasis on high treble, and "less silence between the notes". It sounds more technical, and less acoustical/realistic. The output of my PowerMac G5 resembles the iPod Video much more than the iPod Classic. I suspect there is a mismatch in the group delay of the treble, where the treble arrives "faster" than the lower frequencies. That's a typical error in DA-conversion and filtering, that can be fixed by FIR filtering, or masked by a slight attenuation (0.1-0.3dB of treble starting from 8kHz).
Some say it is a small issue, but I think it is a huge issue.
Annoyances/strange things:
- Sound quality. A bit more natural and acoustical instead of technical.
- When the screen blanks during playing, it shows a clock, and a battery indicator. When music plays I'd like to see where in the track I am, what number is playing etc., without having to touch the iPod to wake its screen up.
- EU sound limit. With my Sennheiser HD650 and some soft recordings, it is too soft. I hope for a fast update of GoPod, to be able to accomplish normal sound levels.
- Clicker hardly audible through the headphones.
- Everywhere album art in the main menu, except for the "Now Playing" menu, which only shows a title.
Some bugs:
- The time shown when the screen blanks is always in US (no AM/PM!) format instead of the selected 24h format in the preferences.
- The date is always shown in US format (m/d/y instead of d/m/y).
- Home addresses and office addresses in the address book are all mentioned as home address on the iPod.
- The camera connector doesn't work.
- Equalizer heavily distorting. It is amazing that this is the case since the 1G iPod, and nothing has ever been done to fix this.
I hope a firmware update will solve things quickly. Especially the sound quality issue should be solved; this is the primary reason to buy an iPod.
Marc

Answer 1

As an audio engineer I must disagree with your conclusions regarding severity of the issue. The variations found (0.1dB) are simply too small to amount to anything significant. 1dB is DEFINED as the smallest volume change that a human can perceive, and 0.1dB is a variation far smaller than batch discrepancies in any group of identical speakers or headphones you care to name.
Furthermore, the so-called “incorrect timing response” is EXACTLY what one SHOULD see given a small change in treble response - this is systems engineering 101, folks. The time and frequency domains are different reflections of the same behavior.
I will add that this “timing response” is far more linear and of a smaller magnitude than any mechanical device (speaker, headphone) you will find on the planet. These mechanical necessities will simply swamp any small variation in the electronics.
As to spatial effects - I will step into deeper waters here and state that any that exist in 2 channel recordings are subject to an awful lot of much larger forces, such as room acoustics, headphone behaviors, and a lot of psychology. Spatial data simply is so poorly represented in 2 channel audio that when it seems to work it is often as not a fluke - the data just isn’t there in a reliable form. When we have recordings that actually represent multi-channel, multi-direction room reflections and multi-channel, multi-direction playback systems we might have something, but not today.
So, is the iPod perfect? No. But I sincerely doubt that these changes are in fact audible, even given good quality headphones. I have listened to far too many pieces of gear to believe that.