同位素rx3 vs. Adobe Audition, Part 1: Declipping and Crackle-and-Pop Removal--UPDATED with iZotope Tutorial!

For many Creative Cloud users, Adobe Audition is the obvious choice for audio editor. Not only is the price right, you get roundtrip editing with other CC tools like Adobe Premiere Pro. So when I saw the press release on iZotope RX 3, 我想知道, does this provide any functions I can’t get in Audition, 或者更好地执行任何功能?

Since I’m primarily a shooter/editor, 而不是音响师, I figured I would focus on those problems that occur most frequently in my productions. In the first of this two-part article, I’ll focus on declipping and crackle-and-pop removal; in the second I’ll compare functionality for noise and echo/reverb removal. This isn’t a full review of RX 3; just a comparison with Audition for these video-related functions.

我是如何测试的

对于所有这些任务, I came up with a sample file or two, and performed the function in RX 3, Adobe Audition CC, 和试听CS6. All before-and-after files are included below so you can hear the problem and how well each program resolved it.

作为预览, though I’ve sworn by Audition’s Auto Heal function since it appeared many years and many versions ago, I produced much better results faster with iZotope’s Spectral Repair, which performs the same function. Though I haven’t finished my testing, I’m leaning towards a similar conclusion for noise reduction, 尽管在每个例子中, Audition CC seemed to outperform Audition CS6. If you experience either of these problems, iZotope值得一看，和re is a ten-day free trial available.

郑重声明, 有两个iZotope版本, rx3(一般售价349美元), 售价249美元), rx3高级版(1美元),199/$749). 你可以看到 这里比较; I used some of the Advanced configuration functions in my tests, 还有一些函数, 比如Dereverb模块, are available only in the Advanced version.

Declipping

Clipping is what occurs when you record the audio so hot that it flatlines against the edges of the waveform. 我从来没这么做过, 当然(哈), 哈哈), so I recorded a new audio file to use specifically for this test. 你可以在里面看到文件 图1(下面), with flatlines atop each audio peak. Not only do these peaks sound distorted, but the resulting audio file lacks dynamic range, since the true high points were given a digital crew cut. The obvious measure of the repair tool is how much it minimizes this distortion and how much it restores the dynamic range.

图1. The declipping function in iZotope RX 3. (Click on the image to see a larger version of the screenshot.)

Declipping was not a function that I was familiar with, so I relied on company-supplied tutorials to learn how to use the function in the respective programs. 你可以看到 iZotope教程在这里，和 Adobe教程. 虽然我显然不是专家, these aren’t rocket scientist-type functions and I spent a good bit of time experimenting to get the best results.

While all tested programs did a good job eliminating the distortion, I found iZotope easier to use and thought that it produced a slightly greater dynamic range. 使用Audition CC和CS6时, the Restore Heavily Clipped setting reduced gain by 12dB, and created a waveform that was deeper on the bottom than on top. Normalization pushed the bottom peaks to 0dB, but left the top peaks at about 4.5dB. I boosted these by 3dB to get the overall levels consistent with the iZotope file, 虽然还是有点大.

Of all the tests that I performed, I’m least confident about the results produced for this one. Not only was the test file synthetic, but it was a problem that I’ve never attempted to resolve in the real world. If you have a file that needs declipping, I recommend downloading the iZotope file, watching the tutorial and giving it a shot.

剪辑音频文件跟随.

Top to bottom: the original source file, iZotope版本, 试听CS6版本, 以及Audition CC版本.