GRM Tools ST (Mac/Win)

Dec 1, 2003 12:00 PM, By Peter Freeman

           

France's INA-GRM has been producing innovative sound-processing software for a number of years. Starting in the 1990s with their original GRM Tools standalone application and continuing to more recent TDM plug-ins, they've earned a reputation for creating powerful and imaginative products. The new GRM Tools ST (VST $399, RTAS/HTDM/AS/VST bundle, $549) is the latest installment in the evolution of their sound-shaping offerings.

There are four plug-ins in the ST (Spectral Transform) package: Contrast, Freq Warp, Shift, and Equalize. All are frequency-domain processors that provide powerful ways to manipulate audio in real time. Under Mac OS 9, GRM Tools ST runs only as an RTAS plug-in; under OS X, there's support for RTAS, HTDM, and AudioSuite. VST support is available under OS X and in Windows XP.

First Partial

The Contrast plug-in works by dividing a signal into three separate frequency ranges according to amplitude: weak, medium, and strong. Each group can be adjusted over a huge volume range using sliders for radical effects like turning a sound “inside out” (details that were weak become strong and vice versa) or for subtle but unusual adjustments to make something sound “not quite normal” but still familiar.

Equalize is a one-third octave, 31-band graphic EQ. It offers -96 dB to +12 dB of cut/boost for each band, as well as some useful tools to manipulate groups of bands for interesting results. One such tool is the Elastic String, which lets you create smooth EQ curves using multiple bands with a single gesture. Another is the now familiar SuperSlider, a feature common to all GRM plug-ins. It lets you quickly interpolate between presets with a single slider, either manually (by dragging) or over a user-specified time interval.

FreqWarp is a conceptually simple but novel plug-in that lets you remap the frequency content of a signal using a transfer function (basically an x-y graph where the x-axis is the original frequency and the y-axis is the output frequency). In practice, you use breakpoints to manipulate the “transfer line,” which controls what incoming frequencies will be transposed to what outgoing frequencies. For example, you could create a line that would send all frequency information at 4 kHz up to 8 kHz and anything at 100 Hz up to 300 Hz, and so forth. This amounts to spectral rearrangement of sounds in near-real time, with a reasonably simple and elegant interface.

Finally, Shift allows you to use frequency scaling and/or frequency shifting to transpose or transform a sound. Using its 2-D controller (a variant of an x-y controller), you can transpose a sound by dragging up and down and transform by dragging left and right. Even though these two basic functions aren't new in themselves, the pairing of them on a single controller does allow for some fresh and interesting possibilities.

In Use

As with any shiny new processing toy, I felt the urge to try the ST plug-ins on a whole bunch of different sound sources, from individual drum tracks to guitars to vocals. The overall verdict: rad! What I really liked about these plug-ins was the fact that they are frequency-domain based, not time-domain based, so it's possible to retain clarity even if there's radical deconstruction and reconstruction going on.

Also, very subtle to very extreme effects are possible, and the results vary widely depending on what's being processed. This takes things beyond the realm of “here's a nice flavor that I'll quickly get sick of and not want to use any more” into the “I wonder what they'll do to this type of sound?” arena. This is most welcome indeed.

I really liked these plug-ins. GRM always has a knack for making very musical-sounding tools that have their own specific sonic “footprint” or character, and these are no exception. The plug-ins employ some intensive calculations, so the latency factor is substantial (but nothing that can't be cured with a little track-shifting after the fact). I haven't heard this range of sounds from other plug-ins, largely because the GRM Tools aren't simply “me-too” versions of well-established effects. Rather, they attempt to open up some fresh possibilities, and I think they've thoroughly succeeded. I recommend them highly.

GRM/Electronic Music Foundation (distributor)
tel. (888) 749-9998 or (518) 434-4110
e-mail grmtools@emf.org
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