In this lesson we'll cover some of the limitations that hard-ware and software place on our sound editing, and show you how ...
to deal with issues such as hum in Adobe Soundbooth.
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Let us go ahead and open up for more examples. Again we will be on our media resources folder. This time, we will go to Spectra examples and will just select everything.
Let us take a look at the Drum groove first. Now let us take a closer look at the very colorful spectral display and the information it give us. I trust it when you get used to audio display spectrally, you will wonder how you ever survived without it, instead of being a two dimensional representation of our sound, like the waveform view above it, the spectral display actually gives us three dimensions of information. You can consider color to be the third access as a way to represent depth on our flat two dimensional screens. The x-axis serves as the exact same purpose on spectral display as it does on the wave form. It represents time. This makes it incredibly easy to resolve which blotches of color correspond to which bumps in the waveform, as they will be directly above in under one another.
The y-axis in the spectral display corresponds not to amplitude, but to frequency. Lower frequencies appear at the bottom of the display, higher frequencies are at the top. The highest frequency displayed in this case just over 20,000 hertz is directly related to the sample rate of the current clip being edited. For example, these clips sample rate is 44,100 hertz. The highest tone that can be reproduced by any file at a given sample rate is half of that sample rate, which is why we find our ceiling here to be just above 20,000 hertz. More specifically, it would be 22,050 hertz. We can see if we panned down here a little bit that we do have a clip recorded at a 192,000 hertz on much higher sample rate.
That clip is the Gamelan high Res. Let us come up here, select it, take a look now. Our highest frequency that is represented here in our spectral display is now just over 40,000 hertz. You may notice that 40,000 hertz is actually nowhere near half of 196,000. This file as it exist would be able to reproduce tones up to 96,000 hertz, that being half of a 192,000. However, our audio hardware in the computer is only capable of reproducing sound that is recorded at up to 96,000 hertz. This means that any sound recorded above that sampling rate will be played back, but it will be played back at the lower rate. Soundbooth spectral display reflects this as well. It takes into account the maximum sampling rate that your hardware is able to play back, and limit itself to that range of audio. Just so it does not display information that you are not able to use.
The z-axis in spectral display corresponds to amplitude, and it is represented by color. Blacks, blues, and purples are low values. Reds are medium values, and yellows are high values. Pitched signals as we have seen will typically look like cascades of horizontal lines. While noise looks more like blotchy regions of color. I am just going to move up to the editor pull down and choose Drum Groove. Understanding what is in the spectral display can give you an insight into your audio beyond what is possible otherwise. It is easy to see relative pitch, such as one tones are ascending and descending. And isolate problem areas for clean up with much greater accuracy than before.
The one thing that is harder to see is the overall combined volume, the sum total of the whole signal. Thankfully, Soundbooth gives you the waveform view on top. So all of that data is readily available to you as well. Soundbooth’s ability to actually make selective edits inside the spectral display is incredibly useful, as you will see in later lessons giving you ultimate control over pinpoint accurate notice reduction and other frequency dependent task. There are a few further options that Soundbooth offers that allow you to tell it how to display this spectral information. Over here on your tasks panel, select the remove a sound option. We will look first at the resolution here which we have currently set to medium. Clicking on it we find three options available to us. Fast, medium, and slow. Let us change the fast and see w