Program Your Synth Like a Pro: Filters
Now that you’ve developed a unique sound from your sound source, you’re ready to make it even more unique through the use of modifiers. Depending on your synth equipment, there’s a good chance that you can utilize multiple modifiers to create a very specific sound that will help you accomplish the goal that you’re working toward. For many synth sounds, the first modifier that is utilized is a filter.
The proper use of a filter is where the amateurs get separated from the pros. Here’s why.
Maximize the Usage of Your Synth’s Filter
Many people who start experimenting with a synth look at the filter as a basic means of manipulating the sound, but it is much more than that. Just as the waveform adjustments at the sound source can add harmonics to the audio path you’ve generated, a filter’s job is to take away specific harmonics from the sound. You might have heard of the term “subtractive synthesis.” This is why that term was created!
Most synths have at least one filter that you can adjust to change which harmonics you want to have removed from the sound. This is where you will be able to change your sound through:
- adjusting the filter resonance,
- changing the slope of the harmonics itself,
- adjusting the cutoff frequency of the harmonics, and
- choosing which harmonics you want to filter out.
These four basic components are on most synths. You may have other filter adjustments you can make, but these are the four you’ll need to master to program your synth like a pro.
No Matter What, You’ve Got a Low Pass Filter
Most synths will allow you to choose which filter you want to implement, but not every synth does. If you just have one filter on your synth, then you’ve got a Low Pass filter. This filter helps to eliminate some of the higher frequency harmonics that have originated from the source sound. What you’re doing is creating a frequency slope in regards to the sounds that remain audible as the path goes through the filter. Low pass filters allow lower frequencies to pass through the filter to the next stop on the path you’re creating. On the other hand, a High Pass filter would do the opposite, allowing higher frequencies through while blocking lower frequencies.
Can You Manipulate the Subtractive Synthesis Even More?
Maybe you’ve got a cutoff frequency that you can implement with your filter. If so, then you can adjust where the cutoff of the frequencies that can pass through the filter are located. You’re essentially using this control to allow more frequencies or to block more frequencies that the filter allows to pass through onto the next stage of the audio path you’re creating.
You can also adjust the slope, which is sometimes called the roll-off, of sounds that occur after you’ve finalized the cutoff frequency filter. This filter adjustment controls the attenuation, or the steepness of the sound slope, allowing more frequencies to proceed through the filter.
The resonance of the sound can also be controlled through the filter on some synths. This control lets you boost the specific frequencies at the cutoff frequency that you’ve implemented. If you’re a singer, it would be like increasing the sounds of the lead vocalist while the backup vocalists continue to sing at the same volume. It puts a “spike,” if you will, in the sound slope you’ve created, right at that cutoff frequency.
Filters Make an Audio Path Truly Unique
There are literally millions of variations in sound frequencies that a filter can create for you, even with just a basic synth. Mastering these variations will not only help you program your synth like a pro, but also help you create those perfect sounds that you want for your composition or other need. Start building your own unique audio path today.