Clipping/Distortion mystery

[ravenplenty]

I have resigned myself to the fact that loud songs will clip/distort if I have a bass boosting eq setting applied. They seem not to have built any headroom into the iPod. However, oddly enough I recently had an album which for some reason had the volume set to +100% in the iTunes options (Get Info). It was incredibly loud compared to other albums, but...no distortion. How is it that my iPod can play a song that loud cleanly, yet distort badly on a much quieter song when the bass is boosted?

I'm guessing the bass is being boosted and then fed into the iPod pre-amp, whereas the volume boost setting happens after the pre-amp. Still, seems like there's no need for distorted bass.

Not sure what I hope to accomplish by posting this, it's not going to "fix" my iPod. Just commiserating I guess.

[mrflash]

I'm taking a guess it might be to do with the production of the tracks in question. Tracks 10 years ago left masses of headroom for the track to be bumped up and into by adjusting the EQ. Modern tracks are compressed to the nth degree so when you looks at the soundwave of the track instead of being peaks and lows from the bass to the breaks it resembles a brick. Think you realise this already from the way you've written it, but your IPod's trying to amplify the volume but the production has left it nowhere to go.

[ThreeDee]

I also have noticed this with my iPod 6G. Try playing a track with lots of bass, and then EQ set to "R&B" or "Bass booster, and you will hear lots of clipping/distortion, even with good headphones.

However , if I playback the exact same track with iTunes on my Mac, it sounds fine.

I'm guessing it's an issue with the new sound processor on the 6G iPod, which was switched from some Wolfson-made chip to some Cirrus-made chip, but I don't have a 5G iPod to compare it with.
http://homepage.mac.com/marc.heijligers/audio/ipod/comparison/measurements/measurements.html

P.S.: Does anyone know if the new 120GB iPod fixes this issue?

[mrflash]

If it plays fine in ITunes but is distorted on your IPod and you haven't edited the track (turned down the track gain etc.) I would figure it has to be something to do with the IPod chips. If it plays fine on the 5G and matches the playback on ITunes it's down to whatever the difference in construction between the 5G and the 6G is I would guess.

[Mikey-San]

even with good headphones.

Note that many really good sets need more power than portable players can reasonably provide, in order to avoid distortion.