I was originally going to do a tutorial on ‘Bass Focusing’, which is what this tutorial is actually about, but you should bare in mind that what I will show you can be used for all kinds of things. What I want to show you is how to split a sound into frequency ranges properly.
The challenge is to split a sound up into, say, three frequency bands. Bass, mid and high. Initially, if you are used to using effect groupings this will seem easy. The trouble is that the the EQ8 plugin doesn’t split frequencies faithfully. If you split a signal into two exact copies and use an EQ8 on each, set to the same cut-off frequency but set to low pass and high pass respectively, you get a band rejection at the cut-off frequency. Try it. I’m not sure why. Possibly something to do with phase non-linearity. The EQ3 suffers from an even more extreme problem in that the EQ on its own alters the frequency content of the signal. Just putting one in the track changes it. I’m fairly certain that is to do with phase non-linearity of the plug-in.
Anyway, the trick is in the multi-band compressor. It has a built in phase linear frequency splitter that works very transparently.
An example scenario: You want to reduce the stereo width of the bass frequencies of your track.
This is a very good idea in a lot of cases. It’ll often make the track more focused and remove some of the ‘bloat’, making is sit together better. To do this you should stick a MB compressor in the channel. Group it. Set macros up for the two split frequency sliders (where the litter green pips are in the pic):
Next, duplicate that Chain twice and call them Low, Mid and High. The macros are also duplicated so you should be able to change the cut-offs of all three at once keeping them in sync; so that you don’t accidentally mess up the EQ. Go through each chain soloing the respective band for each chain:
There you have it, an almost perfect frequency range splitter. For bass focus you can stick a utility after the MB compressor in the Low chain and set the utility’s ‘width’ to 0.0%:
Fiddle with the Low-Mid Crossover macro. This controls the upper limit of the frequencies that will be made mono. What you set this to is up to you. About 200 is roughly where it should sit if you want preserve the stereo image of your track but sort out the bass.
Once you have this you could use it to do other frequency dependent stuff, like doing some stereo panning trickery on the higher frequencies.
NB: Always remember to use limiters! Especially at the end of the channel.