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Hardware And Software Reviews |
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T.C.
Electronics Restoration Suite 2.0: |
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TC Electronics Restoration Suite 2.0 A Software Review By Read G. Burgan Digital audio noise reduction software provides those of us in radio with the ability to give our listeners an audio quality that we couldn’t even have imagined a few years ago. When NR software first appeared, it was eagerly greeted by those of us who were looking for ways to clean up long play records, tape-recorded interviews and noisy telco feeds. The initial software left much to be desired. Often it was unable to deal with certain kinds of noise. Sometimes it created artifacts worse than the original problems. Great improvements have been made in the two basic types of NR tools: Impulsive noise reduction -- to eliminate pops and clicks; and broad band noise reduction -- to eliminate continuous noise like vinyl record surface noise and air conditioning sound. The improvements have been so great that the question is: Can a new entry into the NR software field offer any improvements? TC Electronics thinks so. I have been using TC’s Restoration Suite 2.0 for several months. Here is what I’ve found. Power Core First, Restoration Suite 2.0 is part of a growing number of software programs that require an add-on plug-in PCI card or an external USB external hardware box. This provides a DSP processor that transfers a portion of the software’s processing from the host computer’s CPU to the add-on processor. In this case the processor is the TC Electronics PCI MKII with a retail cost of $1,495. The PCI MKII card supports a variety of software plug-in’s available from TC Electronics or third party providers including Sony, Waldorf and D-Sound. The software should run on any MAC or PC computer with an audio editor that supports VST or RTAS plug-in’s. PC computers require Windows XP; Mac computers require OS X 10.3 or higher. TC Electronics supplied me with a loaner card for my computer. It was easy to install. The card comes with a number of useful, high quality digital audio tools including compressors, equalizers and reverbs. When I was done testing the Restoration Suite software, I liked the card sufficiently well that I exercised my option to purchase the loaner card. Descratch Second, Restoration Suite 2.0 contains more tools than are found in the typical digital audio NR package: 1. Descratch; 2. DeClick; 3. DeCrackle; 4. DeNoise; and 5. DeThump. There is some overlap in the tools’ functions. For example, Both Descratch and DeClick will remove pops and clicks, and both DeClick and DeCrackle can remove crackle. Because of this it is unlikely that you would use all of the NR tools in the suite in any given situation. Rather you would choose the two or three that best deal with your particular noise problem. Is there anything in Restoration Suite that sets it apart from other NR software? Yes! DeScratch is the gem in Restoration Suite 2.0. Until now, NR software has had problems removing large pops, clicks and scratches. Most impulsive noise filters will do an adequate job of removing small to moderately large pops and clicks. But when it comes to large pops and clicks, all of the impulsive noise filters that I have used are inadequate. In most cases they end up converting the large impulsive noise into a smaller low frequency bump. Unfortunately, the low frequency bump can be as annoying as the larger pop or click and almost impossible to locate for manual removal. DeScratch is the first automatic digital plug-in that I have found that is capable of removing very large pops and clicks without leaving an artifact in it’s place. It took me a while to properly set the various parameters, but once I did, I was favorably impressed with its ability to remove many of the large pops and clicks that in the past had eluded any number of digital tools. DeScratch has three basic controls: Threshold, Scratch Size and Quality, plus an additional control for linking the channels. If you have a badly degraded recording with many pops and clicks, this plug-in can consume a lot of your computer’s CPU -- even with the add-on card’s DSP taking on some of the processing load. While this shouldn’t affect the quality of the restoration, it might affect your ability to preview the restoration in real-time. And this is where the Quality setting helps. In situations where the CPU load is excessively high, you can lower the CPU load by selecting the lowest quality setting. When you’re satisfied with what you’re hearing during the preview, you can reset the Quality control to the highest setting and run the process. DeNoise Of the remaining tools in Restoration Suite, DeNoise offers features that are better than many similar offerings by other companies. DeNoise is designed to remove continuous noise such as record surface noise or tape hiss. DeNoise provides three different modes for noise removal. The default setting is Automatic. In this mode, the software automatically evaluates the audio and determines for itself what is noise and what is legitimate sound and creates its own noise print and removes the noise based on that. The only control the user needs to concern himself with is the Reduction slider that determines how much noise will be removed by the noise print. In the Automatic mode, the software is continuously evaluating the sound and changing the noise print as necessary to remove the noise. There is a Time setting that the user can adjust that affects how quickly the automatic noise print will change in relation to changes in the audio signal How well does the automatic mode work? I found that for most average situations in which there is a moderate amount of surface noise, the Automatic mode performed very well. When it comes to the several seconds of silence between record cuts, lacking any audio to compare against the noise, it may accept the surface noise as audio and not provide noise reduction. But as soon as the next cut begins, it is again able to distinguish between the sound and noise. By clicking on the Auto mode button, you can lock the noise print. In effect, the previously moving noise print becomes stationary -- just as if one had first created a noise print by selecting an isolated section of noise from the recording. I found that this often worked the best enabling the software to continue reducing the noise during the several seconds of silence between record cuts. Like traditional broad band noise reduction software, DeNoise has a Fingerprint mode that allows you to select a noise-only portion of the sound and create your own noise print that the software will then use in removing the noise. In dealing with sound that has high levels of noise, this is probably the best way of removing unwanted noise. You can set the capture time anywhere from 10 to 3000 ms. Finally, DeNoise has a Draw mode that is essentially a graphical editor that allows you to adjust an existing noise print created by the Automatic or Fingerprint modes or to create an entirely new noise print from scratch. In the Draw mode, the noise print has a series of handles along the points of the noise print that can be dragged up or down to modify the shape of the noise print. New handles can be added or existing ones removed and the left and right noise prints can be independently adjusted if desired. A Ceiling slider allows the user to limit just how high the noise print will be applied. This is a nice feature as it recognizes that at high levels, the sound itself is often sufficient to mask the noise. A Bias parameter allows the user to move the entire noise print up or down by as much as 20 dB. This makes it easy to fine-tune the noise print. There is also a Character parameter that lets you tailor the reduction process to the kind of sound that your are restoring. Type 2 protects the high frequency content more than Type 1 at the expense of a little less noise reduction. All in all, DeNoise has been well designed to provide a variety of user friendly options that produce a very effective noise reduction. I was pleased with the results that I was hearing. The algorithms are both effective in removing noise and in maintaining the original character of the sound with minimal and in most cases, no discernible artifacts. DeClick-DeCrackle-DeThump
DeClick performs the kind of impulse
noise removal associated with most traditional pop/click filters. It has
only two slider controls: Threshold and Crackle. The Threshold control
determines how much impulsive noise is removed, while the Crackle determines
what kind of impulsive noise is removed. If set all the way to the left, it
will remove only crackle. Set all the way to the right, it will remove only
clicks. |
