Impulse Responses — Part 1 [Analyzing Mixing Effects]

Показать описание

The seventh video in the analyzing effects series from Eric Tarr. This one is all about impulse responses.

—

Transcript excerpt:

I've been going through a series of videos where I'm demonstrating techniques that you can use to analyze your effects plug-ins.

In this video, I'm going to demonstrate how you can measure the processing that occurs within certain types of audio effects by using an impulse response.

The idea with an impulse response is that if you're working with digital signals, a digital signal is made up of, or comprised of, a sequence of measured amplitude values.

Many times, we refer to those measured amplitude values as samples. So, a digital signal is a sequence of samples, one after another. If I were to be able to remove or isolate one of those samples from the rest of the signal, what I'd be left over with is something I'll call an “impulse.” It's a special kind of signal that just represents one sample at one given point in time.

What I can do then, is send that sample, or send that impulse through an audio effect, and see how that effect is going to process that individual sample. I can measure that.

Then, if I know and I measure what that processor does to one sample, I can infer what it's going to do with all of the other samples in my signal. All of the other ones from my original signal.

This process is called “measuring an impulse response,” and then what you can do is take that impulse response, and load it into a special type of plug-in. A convolution plugin. Then you can apply that impulse response to whatever kind of signal that you send through it, or whatever other kinds of samples, or sequence of samples, that you want to put through, and apply this impulse response to by using convolution.

I'm going to demonstrate this whole process in this video. Let me show you what I'm working with.