[flobear]

First post! as the title says, my speaker makes a buzzing sound whenever it's turned on. The model is Bose SoundDock Portable (link to bose site), I got it as a gift a couple years ago. I actually noticed the buzzing a year ago, but it was so faint that I had to put my ear next to the speaker to hear it properly. It didn't bother me if I turned the volume up. But recently the buzzing has become very noticable and it's become very distracting, like a ringing sound. I don't know if this info helps, but I've really only used the Sounddock as my Macbook Pro's speaker, about 15-25 hours of use a week. To get an idea of how loud I play my music on average, my room is roughly 14x20ft and from across the room it would be between moderate and quiet, too loud to count as background sound. Another thing I noticed is that when I plug in the laptop charger (not necessarily charging), the buzz becomes about half as soft.
 
So, is there any way to fix it? or at least reduce it... I've already read some other threads about buzzing speakers, but they have slightly different problems. I don't use any extra equipment with my speaker, only the cable and laptop. 
 
thanks guys

 

[NA Blur]

Couple things to try:
 
1.)  Turn the volume up on your PC to 100% and use the DOC to control the volume
2.)  Plug both into the same wall outlet.  This is the first step in removing ground loop noise.
3.)  Without plugging in your laptop the buzzing should be worse as it is not on a stable ground.  The charger almost all laptops use are two-prong plus with no grounding.
 
Links:
http://www.digitaldjtips.com/2011/07/fixing-laptop-hum-on-ac-power/
 
http://www.youtube.com/watch?v=jSA2F1AwboU
 
You can always try a hum eliminator such as this one:
http://www.amazon.com/Behringer-HD400-2-Channel-Hum-Destroyer/dp/B000KUD2G4
 
Hope that helps.

 

[flobear]

So i tried your advice:
1. That helped a lot! Is there an explanation why...? lol. Before, I had my laptop at about 50-60%, iTunes at max, and used the speaker to adjust the rest of the volume.
2. They're already plugged into the same outlet
3. So the number of prongs is a factor? Mac chargers have the option of switching out the double prong with a triple prong plug, but I thought that was only for extension purposes (pics below). Will it affect how my mac charges also?
 
Thanks for the help!

 

[NA Blur]

If the input signal is too low then the amp has to be driven too high which often causes clipping ( flattening out of a sinusoidal signal ).
 
Basically if the amp has to work too hard to amplify the signal to the listening levels you want the signal begins to clip even if you turn the knob up.  You can read more about it here:
 
http://en.wikipedia.org/wiki/Clipping_%28audio%29