GRM Tools ST (Mac/Win)

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 powerful and imaginative products. The new GRM Tools ST (Spectral Transform; VST $399, RTAS/HTDM/AS/VST bundle, $549) is the latest installment in the evolution of their processing tools.
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Overall EM Rating (1 through 5):4.5

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

There are four plug-ins in the ST (Spectral Transform) package:Contrast, Freq Warp, Shift, and Equalize. All are frequency-domainprocessors 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 isavailable under OS X and in Windows XP.

First Partial

The Contrast plug-in works by dividing a signal into three separatefrequency ranges according to amplitude: weak, medium, and strong. Eachgroup can be adjusted over a huge volume range using sliders forradical effects like turning a sound “inside out” (detailsthat were weak become strong and vice versa) or for subtle but unusualadjustments to make something sound “not quite normal” butstill familiar.

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

FreqWarp is a conceptually simple but novel plug-in that lets youremap the frequency content of a signal using a transfer function(basically an x-y graph where the x-axis is the originalfrequency 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 whatoutgoing frequencies. For example, you could create a line that wouldsend all frequency information at 4 kHz up to 8 kHz and anything at 100Hz up to 300 Hz, and so forth. This amounts to spectral rearrangementof sounds in near-real time, with a reasonably simple and elegantinterface.

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

In Use

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

Also, very subtle to very extreme effects are possible, and theresults vary widely depending on what's being processed. This takesthings beyond the realm of “here's a nice flavor that I'llquickly 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 makingvery musical-sounding tools that have their own specific sonic“footprint” or character, and these are no exception. Theplug-ins employ some intensive calculations, so the latency factor issubstantial (but nothing that can't be cured with a littletrack-shifting after the fact). I haven't heard this range of soundsfrom other plug-ins, largely because the GRM Tools aren't simply“me-too” versions of well-established effects. Rather, theyattempt to open up some fresh possibilities, and I think they'vethoroughly succeeded. I recommend them highly.

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