dred2009 wrote:Where do I download a good free de-esser;
I think others have already given some suggestions there, although most DAWs have a de-esser bundled in anyway.
if a de-esser plugin is necessary for mixing vocals;
Not always, but it is quite a common requirement -- largely because of the close-miking technique routinely used for vocal recording.
if it's possible to remove the sibilance with just an EQ;
Yes, but not in real time. It would require a lot of EQ automation as the amount of EQ required has to vary so that it only attenuates the sibilant parts of the vocal, rather than everything all the time.
...and what's the difference between a de-esser and an EQ.
A de-esser is essentially a frequency-selective compressor. There are several variations on the theme. Some attenuate the whole signal, but only when a strong sibilance is detected. Others only attenuate the sibilant region when a strong sibilance is detected. ...but the end result is similar, either way.
It is worth noting that a lot of sibilance can be prevented or reduced at source by experimenting with the position and angle of the microphone. Moving the microphone sideways), slightly away from the direct mouth axis, or higher (so it's level with the forehead but pointing down at the mouth) can often help, or leaning the microphone back so it's at a slant rather than straight-on to the mouth (which reduces it's sensitivity to the high-end vocal components) .