Virtos Noise Wizard Noise Reduction DirectX Plug-ins (review)

The Virtos Noise Wizard is a set of DirectX plug-ins. The individual modules-DeClicker (and De Crackler), DeNoiser, Filter Toolbox, Stereo Processor, and Band Extrapolation-can also be purchased separately. Like most plug-in packages for audio restoration, this one is best used for processing larger sections of the material while making several passes through the problem audio. The Noise Wizard package excels in terms of price, user-friendliness, and the number of modules included with the complete set. It features a DeClicker with DeCrackler, a Noise Analysis module with a Noise Print module, a Filter Toolbox, a Band Extrapolation unit, and a Stereo Processor. Prior to purchase, users may install a fully functional trial download (which beeps every few seconds).

On some plug-ins, playback, previewing, and looping audio selections can be difficult if your audio editor does not allow playback while the plug-in is open. The DeNoiser (see Figure 5) features a Preview button, and also a Selection button allowing you to play your audio, monitor DeNoising, then enter a longer selection of audio to be processed without having to close the plug-in. Most of the modules also feature a Residual check box allowing you to monitor what is being removed from the audio, and also a Bypass to hear the untouched version as well.

Figure 5.

DeNoiser interface.

For average use, Noise Wizard is easy to install, handy to use, and it can process multiple tracks in one pass. If your noise problems are typical impulse noises which can be solved by gating, or narrowband noise, such as hum, which could use a notch filter (see Figure 6),then this software will work wonderfully for you. For extremely nasty broadband noise, you may have to feather the DeNoiser level slider, Gain Floor knob, Attack Time knob, and Release Time knob in order to lower the noise floor while attempting to preserve as many of your harmonically related FFT bins as possible. Following that, if the music beneath the noise has not been gated out altogether, then the Band Extrapolation module can help you add harmonic life again to the signal. Finally, you can turn your mono signal into a stereo one, or alternatively narrow or increase the field of your existing stereo signal if you need to do that. A 32-band Graphic Equalizer in the package would have been nice, but pricing was probably a factor in not including it. Perhaps future upgrades will offer one.

The user settings and Help pages seem sensible and straightforward, and genuinely helpful. You can print the Help pages, and the user settings allow for log or linear curves with your processing. You can save and load presets to help save time.

Figure 6.

Filter Toolbox interface.

As a DirectX plug-in package, Noise Wizard runs only on Windows platforms (Windows 95/98/ME or Windows NT/2000/XP) with a wave-editor host supporting DirectX 6.0 or later audio plug-ins. You will also need at least a 350 MHz processor with 64 MB of RAM, and at least 2 MB free hard disk space. A stereo soundcard, loudspeakers or headphones, and a mouse are also required.