Applied Acoustics Systems Strum Acoustics GS-1 Review

Applied Acoustic Systems Strum Acoustics GS-1 synthesizer reviewed by EM writer Marty Cutler in EM March 2009 issue
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Strum Acoustic GS-1 offers a healthy batch of guitar-oriented sound-design controls.

It's axiomatic that even though synths can evoke realistic-sounding acoustic instruments, the performance provides the most important impression of realism. Many synthesizers attempt to emulate guitars, with varying degrees of success, replicating the nuances of idiomatic chord voicings, guitar strumming, and other articulations.

Applied Acoustics Systems is known for its physically modeled software instruments, including Lounge Lizard, Tassman, and String Studio. The company's latest offering is Strum Acoustic GS-1 ($229), which proffers guitar-focused sound-design options coupled with a sophisticated array of authentic guitar-performance techniques. Applied Acoustics provides VST, AU, and RTAS versions for the Mac; VST and RTAS for Windows; and standalone versions for both platforms. You can download the software from the company's Web site or buy a boxed version from a dealer.


Strum provides a generous complement of timbral variations, and its acoustic guitar sounds are more detailed than those of String Studio, whose broader palette extends well beyond guitar emulation. Strum's presets include three basic instrument types: steel-string and nylon-string instruments, a resonator guitar, and processed variations. The steel- and nylon-string instruments sound quite realistic, but the resonator guitar sounds more like a comb filtered variant of the other models than a National steel-bodied guitar or a Dobro.

Apart from the effects panel at the top, which presents menus for EQ, delay and modulation effects, and reverb, you get controls for shaping the guitar's sound and its response to incoming MIDI data. Using controls such as Coupling, Stiffness, and Edge, you can adjust the perceived body size and resonance; your choice of pick, fingers, or fingernail; and more.

You can modulate pick position relative to the bridge and neck in real time with smooth and realistic results, the timbre changing from crisp and more nasal near the bridge to deep and mellow as you move toward the neck position (see Web Clip 1).

No acoustic guitar that I have played has had a perfectly consistent response across all six strings, and Strum can respond realistically in this respect. Clicking on any string number at the top left portion of the virtual guitar body enables you to customize that string's settings. You can even adjust individual string gauges. This works hand in hand with Strum's chord-voicing abilities, just as a note's timbre will vary when played from different strings on real guitars.


There are several ways to play Strum, but common to all is the ability to revoice incoming MIDI notes to emulate guitar fingerings. You can choose from several types of movable (or closed-position) chords and open-chord voicings, which are great for folk styles. With closed-position voicings, options include the starting fret position for the chords and whether the root note will be the lowest guitar tone.

With the Auto button off, the instrument waits for the right hand to strum chord positions, which are interpreted from the left hand. You then trigger up- and downstrokes on consecutive diatonic keys above the chord-detection range, and adjacent chromatic keys trigger muted strokes. With the Auto button on, chords played on the keyboard are immediately interpreted and played as downward strokes. I had great fun performing Freddie Green-style comping, which is characterized by predominant quarter-note downstroke chords with lots of harmonic motion.

A built-in player lets you audition and choose from a library of Standard MIDI File loops and rhythm patterns that can follow your chords. You can drag them to MIDI tracks and vary the content or change the feel. If you want more, create your own; the clearly written manual explains the process well.

Strum handles single-note performances well. Play successive legato notes, and hammer-on and pull-off notes are executed flawlessly, without retriggering the attack. Envelopes respond realistically to note durations, so notes played quickly cut off in response to key release, while held notes die off as they would on a real guitar, gradually fading into silence, and with increasing speed at higher pitches.

In addition to standard Pitch Bend, Aftertouch can control the pitch of the strings. Light touches add subtle pitch deviations (as with a real guitar), and increased pressure induces smooth pitch-bend effects. Chords remain intact, with only the highest note affected.


Guitarists might not want to mothball their vintage guitars just yet; Strum Acoustic GS-1 isn't poised to replace all aspects of the guitarist's tricks. The instrument doesn't quite convey all the close-mic, brassy brilliance of a fine acoustic steel-string guitar or the chaotic snap and buzz of zealously overplayed strings. That said, Strum's models are as good as it gets, and its accurate articulation and sophisticated chord voicing make it an utterly convincing chord-melody instrument, an excellent solo voice, and an agile accompanist. I recommend it highly.

Value (1 through 5): 4
Applied Acoustics Systems