I have just instaled my harman kardon ks200 and there appears to be a problem? i can hear the cd spinning louder when listerning to track 1 than i can when listerning to track 10 eg. should there be a...
* Tech Stuff *
Audio CDs do not spin at a constant rate. They are designed to be read (for music) at a "constant linear velocity" of about 1.25 meters per second. The data is written in a tight spiral starting at the inside of the CD. The CD spins the fastest when reading the inside tracks and slows down as it reads towards the outside edge. Imagine circles on the CD surface. The inside ones would be smaller than the outside ones, of course. So, if you are reading evenly-spaced bits on the lines of those circles, you would need to read fewer outside circles per second than the small inside circles.
* Basic Issue *
When the player is reading Track 1 the CD is spinning at about 500 rpm. During the last tracks of a (full) CD it only needs to spin at about 200 rpm. It doesn't work the other way around for compatibility reasons.
* More Info *
This is why you are experiencing the difference in mechanical noise at different tracks. It doesn't necessarily reflect a defect, but understandably, a consumer would prefer a quieter system, which does differ between manufacturers and models (I couldn't specs for a KS200 HK device) Yet, if the noise is substantial, it may very well be indicative of a problem, e.g. something stuck in the drive and being whipped around in a circle at high speed. I wouldn't say this is particularly likely.
* Possible Help *
What would normally mitigate this issue is not getting too close to the player while listening. Normally having the primary listening position several few feet away (across the room) would suffice to minimize noise heard from fans and spooling CDs.
May 14, 2008 |
Televison & Video