T450 : Question about speaker, screen & hard drive..

Hello, so i recently got a T450, made a fresh windows 7 install on it, updated drivers. Then noticed some strange things, first speakers : there is a loud pop sound coming quite frequently. It's like the speakers are turned off and then on again when sound is played.. Why is that?

Next, screen : Does it adapt colors?! I noticed when i'm displaying something dark on screen and then come back on an explorer windows (which means white color mostly), it seems that brightness was lowered, cause the brightness is slowly coming back.. What the heck is that?

Last thing, hard drive : Is it possible to installing a 9.5mm HD or it must be 7mm? I read different things here and there.. That's a nice unit overall, however i'm wondering if speakers aren't lower quality (not just cause of these pops but sound generally) compared to former models..

 

Surprised i didn't get any reply.. Hope to get one during the week-end, i guess i don't have to long to send the unit back if indeed there's something wrong with it!

 

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