Waves: Z-Noise plug-in

Like most plug-ins these days, Z-Noise comes in RTAS/AudioSuite, VST, AU, and MAS flavors. It supports up to 96 kHz resolution (requiring 1 GB of RAM to do so). As a fan of Waves' preceding noise reduction plugin, X-Noise, I instantly felt at home. The new "more musical" algorithm of Z-Noise is much more processor intensive. In Pro Tools LE 7.1 on a 1.25 MHz G4, X-Noise creates a 5120 ms delay while Z-Noise creates a 34702 ms delay at 96 kHz. With Pro Tools set to use 85% of the CPU, I was only able to load three instances of Z-Noise. For this reason, I recommend not using Z-Noise in real-time. So, how well does it work? I was amazed! Both these plug-ins have a Learn function which samples the noise in your track that you'd like removed. For this function to work properly, you need at least 100 ms of pure noise. In a side- by-side comparison, Z-Noise removed more noise than X-Noise, especially in the low end. Z-Noise introduces a few new controls. Transient pre-emphasizes the transients before reduction takes place and de-emphasizes after reduction is done. This seems to add presence and an overall quality to the filtered audio. Knee adjusts the gain- reduction curve to help you fine-tune the personality of the filter. Extract is an alternative to the Learn function. It attempts to find the undesired background noise if you don't have a sample of pure noise for Learn. I was very surprised at how well this worked! Adaptive assumes that the undesired noise is constantly changing and compensates accordingly by using the settings from Learn or Extract as a starting point to create a noise profile that varies along with the whole track. The resolution optimization controls are reworked and relabeled from X-Noise. They are now called Punch, Norm, and Smooth. Smooth provides the highest frequency resolution while using the most CPU. It is best used on audio which doesn't have much attack (e.g. vocals). Punch is a setting best used on plucked or hammered instruments. Norm preserves transients better than Smooth and has better frequency resolution than Punch. For any professional doing tape-to-CD transfer, ADR, or audiobook recording, Z-Noise is a must-have plug-in. ($800 MSRP; www.waves.com)