We all want a fatter sound, that's for sure. There's nothing that gives away an amateur production like a thin sound.
Thin = Amateur
Fat = Pro
It's the ultimate equation of recording.
You can use EQ to achieve a fatter sound. EQ is applied mostly in the bass end, to frequencies around the natural bass presence of the instrument, thus widening the bass spectrum.
You can use compression to achieve a fatter sound, select the ratio and threshold according to taste, but make sure the release time is short, otherwise the sound won't change much.
You can EQ then compress, or compress then EQ. Both are worth experimentation.
All four methods can improve the fatness of a sound. But there is another and potentially better way…
Instead of EQing the signal directly, place the EQ in the side chain of the compressor. Every decent compressor, including plug-ins, has a 'side chain' input that is separate to the main signal input.
The signal supplied to the side chain controls the amount of compression applied to the signal at the main input.
Normally, the two signals are the same, so the input signal controls its own compression. But they can be different.
So connect the signal you want to process to the main input, and take a parallel feed through an equalizer to the side chain input. Use the compression settings you would normally apply for added fatness. You can experiment with these later.
Now, try the EQ. Remember that it is not EQing the signal itself, but the side chain signal. So the output won't sound obviously EQed.
What you will hear however is that the degree of compression changes as you boost different bands of frequencies in the side chain. And as a result, the perceived EQ characteristics of the signal change too.
The magic is however that this is an altogether bigger and fatter way of EQing. It is a dynamic process where the signal level is continuously varied according to the ups and downs of the signal itself, manipulated by the EQ curve you have applied.
This is an amazingly powerful technique. It's almost a surprise that this method of control doesn't have its own dedicated hardware or plug-in.
It only takes a minute to set up, so give it a try. Listen carefully and become the master of the sounds this process makes available.
Maybe I should call this technique 'super-sized EQ' – it's your fattest EQ yet!