T-Fan bracing
Iulius Guitars’ original bracing design produces a rich tone and even projection across the fretboard. To achieve optimal performance, each instrument’s acoustic response is carefully fine-tuned after the final construction steps (buffing and setup). This unique and time-intensive process yields exceptional instruments that are always perfectly tuned and perform at their peak.
Here’s why, and how.
85% of the sound of the acoustic guitar is produced by the first six resonances of its body:
– the acoustic resonance: T(1,1)1
– the soundboard monopole: T(1,1)2
– the back monopole, if active: T(1,1)3
– the soundboard dipoles: T(2,1), T(1,2)
– the soundboard troipoles: T(3,1), T(1,3)
The amplitude and frequency distribution of these modes is largely responsible for the timbre of the instrument, its tonal balance, and the bracing of the soundboard is largely responsible for the amplitude and frequency of the main resonance modes.
During the decades several standard defined the sound and performance of the most diffused instruments.
an excerpt from the manual: Mastering the sound of the acoustic guitar.
Open-type bracing, such as the standard Martin X or fan bracing, usually produces evident higher-order modes, for a rich sound in the midrange.
Small changes in the bracing scheme have almost no effect, as the shape of the upper modes is mainly determined by the size of the soundboard.
Interconnected bracing, such as lattice or triple X, tends to focus most of the acoustic energy on the monopole, generating a powerful sound and projection into space.
The higher-order modes are less evident.
The T-Fan bracing introduces a hybrid concept: a combination of fan design with a longitudinal brace that connects to the upper transversal structural brace. This design optimizes the strength-to-weight ratio of the bracing system, enabling the creation of lightweight structures that produce high-amplitude dipole and tripole resonances.
The equivalent mass of the monopole of the Orchestra model is 58 g, 30% lighter than a standard OM Martin guitar.
The spruce bridge plate and the bracing geometry positions the resonances across a wide range of frequencies, ensuring a balanced acoustic output across the entire fretboard.
Each specific instrument’s bracing is tuned during the build, before closing the box, to compensate for different tonewood properties.
After the instrument is finished, buffed and set up, a final step of fine-tuning is performed using the ETS system and selective interventions on the bracing. This ensures that every main resonance is perfectly positioned between the notes to maximize the beauty of the sound, the balance across the entire fretboard, and the unique voice of each instrument.
Every detail is important when tuning the acoustic of the instrument; a perfect balance that allows the guitar to express its maximum potential, with a coherent, harmonic and juicy sound, plenty of sustain and balance across the fretboard, as you can hear it here:
Each Iulius Guitar model is offered with an individual specification sheet that also reports the frequency response. This data allows you to track the evolution and aging of the instrument over the years, and the ETS system will enable you to fine-tune the main resonances if necessary, to always maintain the guitar at its maximum acoustic potential.
