MasterTools 1.6 (TDM; Mac)Consumers live in a 16-bit world. However, 24-bit recording in Pro Tools provides both added dynamic range and extra headroom when combining multiple tracks. Other than file size, the only downside is that 24-bit tracks need to be reduced to 16 bits for distribution on CD. Mastering engineers have long favored Apogee's UV22 technology when converting higher bit depths to 16-bit resolution, and Apogee's MasterTools TDM plug-in (Mac; $495) brings UV22 right into the Pro Tools environment.
In lieu of simply lopping off eight bits, most approaches to bit reduction involve dithering and noise shaping, which typically yield some degree of sonic coloration. UV22 adds a clump of high-frequency energy at around 22 kHz - above the theoretic threshold of hearing. That approach smooths out nonlinear elements in the dynamic range in much the same way that bias does with analog tape. The result is that it's hard to hear any difference between the 24-bit and 16-bit versions. Discerning ears will even detect an improvement when running a 16-bit source through MasterTools.
Clip JointAside from transparent reduction of bit depth, one of MasterTools's primary functions is to ensure that there is no digital clipping (overs). Users are able to define the number of consecutive full-scale samples that constitute an over. During playback, the software generates a log that displays the time-code locations and duration of any overs that require attention. If users choose not to tweak these points by hand, the software's Nova function will automatically reduce overs to a level that is just below full digital code at 16 bits.
The MasterTools interface shows an expansive trench. The front vertical edges of the trench represent the current left and right audio signals with both peak and average levels and holds; the horizontal lip of the trench floor meters phase correlation between the two channels. The trench walls display a five-second history of those three pieces of information. That unique approach conserves screen space relative to traditional horizontal displays.
Pleasure MeterMasterTools metering is a pleasure. Users can set the headroom scale of the meters as well as the peak hold time. Moreover, the meter's ballistics mirror the strength of the input signal. The program also displays DC offsets between +10 and -10 percent for left and right channels and can automatically compensate for them. Some digital audio converters exhibit a slight DC at their outputs, though Digidesign I/Os are unlikely to have much of a problem in that department.
The remaining controls are straightforward. Auto Black gates any signal that is below a preset threshold. Users can also invert the phase of one or both channels, perform mono checks, and swap channels to ensure proper stereo placement.
Cool ToolApogee MasterTools is as simple to use because it is sonically transparent. It is hard to refute the credentials and popularity of this mastering technology. The TDM version requires one DSP chip and comes with two authorizations on floppy disk. Alternatively, users can choose challenge-and-response authorization. For anyone serious about mastering directly from Pro Tools, Apogee MasterTools does the job at only a fraction of the price of the company's hardware alternatives.