Adding DC Offset to Audio File

[Dudebob14]

This might sound funny but my friend and I are creating electronic music and I thought that maybe after we finished up our last track of the album that we should add DC Offset to every track so that all the audio stays only on the top half of the waveform and none goes under 0.
(For artistic purposes. We don't mind our track being quiter than others.)
I've been reading and trying to understand DC Offset but I still don't completely understand it. (Probably because my major in school is not science )
Anyway, if somebody could be nice enough to explain to me what it is in nooby detail and answer my question too, that would be awesome.
Thanks!

[steve]

There is a detailed description of DC offset on Wikipedia: http://en.wikipedia.org/wiki/DC_bias
and a simpler explanation on the Audacity wiki: http://wiki.audacityteam.org/index.php? ... correction

For artistic purposes

Note that audio amplifiers should not output DC and loudspeakers are incapable of producing it (DC offset in terms of air vibration would be a constant air flow in one direction > wind). A large amount of DC from an amplifier can cause loudspeakers to overheat and burn out.

If you want to experiment with DC offset (carefully ) use this "DC Offset Tool" http://forum.audacityteam.org/viewtopic ... 42&t=68463

[Dudebob14]

Excellent!! Thank you so much! I'm new to Audacitys plugins, unfortunately.

How do I add it ito Audacity?

Thanks for the super-fast reponse!!

[kozikowski]

Download it. Copy or drag it to the Audacity plugins folder. Restart Audacity.

As above, sound systems don't like DC very much, those that will even acknowledge that it exists.

If you stand by the railroad tracks as a large train is coming and they blow their horn, you can feel your shirt moving back and forth or vibrating with the very high volume of the tone. If you're holding an empty coffee cup, that's another way to feel the vibrations. That's normal sound. Any big enough sound system can handle that. But when the train goes by and blows your hat off, that's DC. The air pressure is only going one direction and no sound system can deal with that. Your time line with an upward push to the blue waves is the equivalent of the front of the train. If you push the blue waves down, that's the other end of the train where the vacuum behind the last car sucks all the dust and dirt onto the tracks.

Speakers won't do that, either.

You are urged strongly not to connect blue waves like that to a sound system. Even though speakers won't actually do it, they will try when you connect the system or turn on the music.

You may blow the speakers across the floor.

But just once.

Koz

[steve]

You are urged strongly not to connect blue waves like that to a sound system. Even though speakers won't actually do it, they will try when you connect the system or turn on the music.

You may blow the speakers across the floor.

But just once.

At low volume for a short period of time it is unlikely to cause damage, but Koz's warning is a good one. If the volume is turned up loud then the speakers will probably not last for long. The burning smell comes shortly after the speakers have been destroyed.

[kozikowski]

The burning smell comes shortly after the speakers have been destroyed.

It's multi-media. Everybody wins.
Koz

[almoore]

Anyway, if somebody could be nice enough to explain to me what it is in nooby detail and answer my question too, that would be awesome.

Here is my noob explanation. A speaker is kind of like an electric motor. It has a stationary fixed magnet and a voice coil that's attached to a cone. When an alternating electric current, (AC), is applied to the voice coil the resulting electromagnetic, (EM), field interacts with the magnetic field of the fixed magnet causing the voice coil to rapidly move in and out. This, of course, causes the cone to move air that produces the sound waves.

When you apply a direct electric current, (DC), to the voice coil it will produce a stationary EM field that will cause the voice coil to travel in or out, depending on the polarity of the DC, and stay in that position as long as the current is applied. You can try this with a small battery and speaker. I do it sometimes to check the phasing of an unkknown speaker. If the speaker moves outward then the termanal connected to the + side of the battery is the positive phase terminal of the speaker. I usually use a 1.5V AA battery for small speakers but I've used a 9V before too. If too much current is applied to the speaker you can damage the voice coil. The small batteries should be fine but though if you want to experiment.