Ableton/Live/UG/31 Instrument Reference/12 Tension
- Tension models string instruments with physical modeling, made with Applied Acoustics Systems; no samples or wavetables, so it responds to playing like a real string.
- Four exciters (two hammers, a pick and a bow), a string, finger and fret interaction, a damper and several soundboards, plus filters, LFOs, envelopes, MPE, keyboard modes, portamento, vibrato and legato.
- An exciter (hammer, pick or bow) sets the string vibrating. The fret or finger termination sets its length and so its pitch; a damper shortens its decay. The body, through the bridge or a pickup, radiates the sound. Tension adds a filter between string and body.
- String tab: Exciter, Damper, String, Vibrato, Termination, Pickup and Body. Filter/Global tab: Filter, MPE and global performance controls.
- Every section except String and Keyboard can be turned off, which saves CPU.
- The string's physical properties and how it is played.
31.12.2.1 The Exciter Section
- With the Exciter off, only the damper can move the string. With Exciter and Damper both off there is no sound.
31.12.2.2 Exciter Types
- Bow — sustained vibration from stick-and-slip friction, as on violin, viola and cello. Damping is unavailable.
- Hammer — strikes from below once and falls away, as in a piano.
- Hammer (bouncing) — dropped from above and may bounce, as on a hammered dulcimer.
- Plectrum — snaps the string, as on a guitar or harpsichord.
31.12.2.3 Exciter Parameters
- Type-specific: Bow has Force (more is scratchier) and Friction (more gives a faster attack); the Hammers have Mass and Stiffness; Plectrum has Protrusion (less is thinner) and Stiffness.
- Shared: Velocity — how fast the exciter hits. Position — 0% at the termination, 50% at the midpoint. Damping — how much impact force the exciter absorbs; for the bouncing hammer it sets the stiffness of its spring, and more makes a shorter, louder, brighter contact.
- Fix. Pos — keeps the contact point fixed regardless of string length, like a guitar pick. Leave it off for a piano, whose hammers strike about 1/7 of the length.
- Vel and Key modulate by velocity and pitch. Some combinations produce no sound.
31.12.2.4 The Damper Section
- Dampers mute the string, like felt in a piano or a player's fingers, and make sounds of their own.
- Mass — how hard it presses; more mutes faster. Stiffness — felt to metal. Very high values can shorten the string and change its tuning.
- Velocity — how fast the damper lands at key release and lifts at key press; very high values can make a loud release. Works only with Gated on; with Gated off the damper stays on the string.
- Position, Fix. Pos and Key sliders as in the Exciter.
- Damping — overall absorption. Above 50% the damper gets stiff enough to bounce, which lengthens decay again; try it on one repeated key.
The String Section
- Decay with < Key. Ratio — shortens release decay relative to onset decay.
- Inharm — real strings are inharmonic, more so when thicker; raising it detunes upper partials.
- Damping with < Key — more high partials at higher values.
The Vibrato Section
- An LFO on pitch: Delay, Attack, Rate, Amount, < Mod (mod wheel depth relative to Amount) and Error (random variation of rate, amount, delay and attack).
31.12.2.5 The Termination Section
- Models finger, fret and string, which set the string's working length. Finger Mass (with Vel and Key), Finger Stiff and Fret Stiff.
31.12.2.6 The Pickup Section
- An electromagnetic pickup. Position 0% at the termination is brighter and thinner; toward 50% is fuller.
The Body Section
- The body radiates and filters the string's energy; some, like guitars, have an air cavity that boosts lows.
- Body Type after real instruments, Body Size XS to XL (larger is lower), Decay, Str/Body (dry string versus body; fully left bypasses the body), Low Cut and High Cut.
- Volume sets the overall output and is also on the Filter/Global tab.
- A polyphonic filter with envelope, LFO and MIDI modulation, keyboard and portamento options, and a Unison effect.
- Filter — between String and Body, with its own on switch; 2nd- or 4th-order low-pass, band-pass, notch, high-pass or formant. Freq and Res (vowels for formant), each modulated by LFO, envelope and pitch; the LFO and Env sliders need those sections on.
- Filter Envelope — ADSR with Vel on Attack (faster at higher velocity) and Vel on Sustain (higher at higher velocity).
- Filter LFO — sine, triangle, rectangle, stepped random or smooth random; Rate in Hz or synced; Attack and Delay.
- MPE — Pressure and Slide each reach two destinations with amounts; activity LEDs; global Pitch Bend and per-note Note PB ranges.
- Keyboard — Octave, Semi, Detune (±50 cents), Voices, Stretch tuning (sharper highs and flatter lows, or the reverse when negative), Error (random tuning per note) and Priority (High, Low or Last).
- Portamento — Time, Legato (only overlapping notes slide) and Prop. (time scales with the interval).
- Unison — two or four stacked Voices, Detune from subtle chorus to wide, and Delay between voices.
- Volume — shared with the String tab.
- Tension's parts affect each other, so it is easy to find settings that make no sound, or very loud ones; watch levels.
- Think of the sections as one physical object: a slow bow can start an undamped string, but a heavy damper needs a faster bow.
- The presets show it can do much more than strings.
