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View Full Version : I've always wondered...



malmen
2009-07-16, 09:12
.. why a waveform that has a weird DC offset would be dangerous in any way? To me they sound pretty much the same if they're normalized or not.. but I've heard people complain. :)

TerminalStorm
2009-07-16, 16:38
Basicly any DC offset is a bad thing coz you have a current running through a short circuted wire (what speaker basicly is) doing nothing but heating it and eventually causing it to melt.

IIRC clipping can cause DC as well.

Quote from Keith's electronics blog (http://www.neufeld.newton.ks.us/electronics/?p=147):



DC Offset

Why is DC on a speaker output a bad thing? Well, each driver (the individual cone assemblies that mount in a box to form what we call a ďspeakerĒ) has an electromagnetic coil of wire in it. Current through the wire attracts and repels the back of the driver toward and away from a permanent magnet, causing the driver to move in and out, move air back and forth, and make sound.

The coil of wire also gets hot. The fine wire used in driver coils has a much higher resistance than the large wire between the amplifier and the speaker, so the coil is where the majority of the amplifierís power is dissipated. Some of the amplifierís electrical energy is turned into mechanical energy to move the driver, but much of it is turned into heat. Too much heat on a fine wire turns into a bad thing. And extra DC current doesnít make sound; it just heats the wire.

malmen
2009-07-17, 07:05
okay. thank you for the answer. :)