Advice regarding distortion and clipping

[Dratino]

Hi, I've done a search through the forums but there doesn't seem to be a direct answer for my questions.

I've got my B&W P7 headphones recently and am using them with my iDevices. I noticed that one a particular track I have (256kbps AAC from iTunes), there seems to be a slight distortion. This is a movie soundtrack which has a 10s section with lots of sub-bass and rumbling, and I noticed that at the "bassiest" parts, I can hear slight crackling through my headphones. Note that my volume is set at about 75%. I have been reading up about how an underpowered amp can produce clipping and how clipping can be damaging to drivers, and I'm wondering if the distortion is caused by the iDevice internal amp. I've tried listening to the same track in my computer, and the distortion at the rumbling section seems even worse.

With the scenario above, I'm hoping someone would be able to help answer my questions below:

1. Is it possible that my iDevice amp is clipping the bass? Personally I feel that this is quite unlikely as my volume is only set at 75%, maybe 80% maximum.
2. If this is not an amp issue, is it possible for clipping to be "recorded" into the track, and thus my new headphones are picking up the distortion from the poor quality recording/mastering?
3. If it's a track issue, will the distortion be damaging to my headphones?

 

[NA Blur]

Could you please describe your gear a little bit more such as listing the amp and DAC you may be using?
 
Be sure to turn off any EQ settings / filters you may have and test again.
 
Lastly, please try to find a track that distorts with your gear and post a link and someone will chime in with their gear and tell you if they hear it as well.

 

[Dratino]

  Could you please describe your gear a little bit more such as listing the amp and DAC you may be using?
 
Be sure to turn off any EQ settings / filters you may have and test again.
 
Lastly, please try to find a track that distorts with your gear and post a link and someone will chime in with their gear and tell you if they hear it as well.

I don't use any external amp or DAC, just purely playing tracks off my iPad/iPhone.
 
EQ settings are turned off as well, don't usually use any EQ settings anyway.
 
Here's a YouTube link for the track I was listening to... it's a Disney soundtrack (don't judge me ), and the distortion seems to be at 1:51 to 1:57, with a crackling when the bass rumbles...

 

[davidsh]

There's no link..
 
Is the distortion present at lower volumes? It can very well be part of the particlar track you are listening to.

 

[Dratino]

whoops sorry here's the link!
 
http://www.youtube.com/watch?v=5G0xEnuUeVc
 
And after trying out various hardware (including removing my Creative SoundBlaster sound card and using the onboard integrated soundcard), it seems that the reason for the distortion is a severely underpowered Creative soundcard... pfft!