Download More Acoustic Sounding Timbre From Guitar Pickups
Amplified guitars with pickups tend to sound ’dry’ and electric, whether the instrument is acoustic or electric. Vibration or pressure sensing pickups for acoustic guitars do not capture the body vibrations with fidelity and in the electric guitar with magnetic pickups there often is no resonating body at all. Especially with an acoustic guitar there is a need to reinforce the sound by retaining the natural acoustic timbre. In this study we have explored the use of DSP equalization to make the signal from the pickup sound more acoustic. Both acoustic and electric guitar pickups are studied. Different digital filters to simulate acoustic sound are compared, and related estimation techniques for filter parameters are discussed.
Download Digital guitar body mode modulation with one driving parameter
In this study we have developed a digital guitar body mode modulation technique where the modulation can be controlled through one driving parameter. The filtering and modulation is done with frequency-warped recursive filters that have been implemented in real-time on a modern DSP processor. By changing the warping parameter the perceived size of the body can be controlled, by a pedal or automatically, resulting in an interesting effect. This effect is useful both for the electric and the amplified acoustic guitar. Perceptual properties of the effect are studied by a listening experiment. (See also www.acoustics.hut.fi/demo/dafx2000-bodymod/)
Download Morphing Instrument Body Models
In this study we present morphing methods for musical instrument body models using DSP techniques. These methods are able to transform a given body model gradually into another one in a controlled way, and they guarantee stability of the body models at each intermediate step. This enables to morph from a certain sized body model to a larger or smaller one. It is also possible to extrapolate beyond original models, thus creating new interesting (out of this world) instrument bodies. The opportunity to create a time-varying body, i.e., a model that changes in size over time, results in an interesting audio effect. This paper exhibits morphing mainly via guitar body examples, but naturally morphing can also be extended to other instruments with reverberant resonators as their bodies. Morphing from a guitar body model to a violin body model is viewed as an example. Implementation and perceptual issues of the signal processing methods are discussed. For related sound demonstrations, see www.acoustics.hut.fi/demo/ dafx2001-bodymorph/.
Download On the Dynamics of the Harpsichord and its Synthesis
It is common knowledge that the piano was developed to produce a keyboard instrument with a larger dynamic range and higher sound radiation level than the harpsichord possesses. Also, the harpsichord is a plucked string instrument with a very controlled mechanism to excite the string. For these reasons it is often falsely understood that the harpsichord does not exhibit any dynamic variation. On the contrary, the signal analysis and the listening test made in the this study show that minor but audible differences in the dynamic levels exist. The signal analysis portrays that stronger playing forces produce higher levels in harmonics. The energy given by the player is not only distributed to the plucking mechanism but also carried on from the key to the body. This is evident from the increased level of body mode radiation. A synthesis model for approximating the dynamic behavior of the harpsichord is also proposed. It contains gain and timbre control, and a parallel filter structure to simulate the soundboard knock characteristic for high key velocity tones.
Download Real-Time Pitch-Shifting of Musical Signals by a Time-Varying Factor Using Normalized Filtered Correlation Time-Scale Modification
This paper presents a high-quality real-time pitch-shifting algorithm with a time-varying factor for monophonic audio and musical signals. The pitch-shifting algorithm is based on the resampling and time-scale modification method. A new time-scale modification method has been developed which is called the Normalized Filtered Correlation Time-Scale Modification (NFC-TSM) method It uses a ring buffer for time-scaling. The best splicing point is searched in the normalized low-pass filtered signal using the Average Magnitude Difference Function (AMDF). The new method results in low-latency and high-quality pitch-shifting of musical signals.
Download Sound synthesis using an allpass filter chain with audio‐rate coefficient modulation
This paper describes a sound synthesis technique that modulates the coefficients of allpass filter chains using audio-rate frequencies. It was found that modulating a single allpass filter section produces a feedback AM–like spectrum, and that its bandwidth is extended and further processed by non-sinusoidal FM when the sections are cascaded. The cascade length parameter provides dynamic bandwidth control to prevent upper range aliasing artifacts, and the amount of spectral content within that band can be controlled using a modulation index parameter. The technique is capable of synthesizing rich and evolving timbres, including those resembling classic virtual analog waveforms. It can also be used as an audio effect with pitch-tracked input sources. Software and sound examples are available at http://www.acoustics.hut.fi/publications/papers/dafx09-cm/
Download Modeling Methods for the Highly Dispersive Slinky Spring: A Novel Musical Toy
The ’Slinky’ spring is a popular and beloved toy for many children. Like its smaller relatives, used in spring reverberation units, it can produce interesting sonic behaviors. We explore the behavior of the ’Slinky’ spring via measurement, and discover that its sonic characteristics are notably different to those of smaller springs. We discuss methods of modeling the behavior of a Slinky via the use of finite-difference techniques and digital waveguides. We then apply these models in different structures to build a number of interesting tools for computer-based music production.
Download Simulating Idiomatic Playing Styles in a Classical Guitar Synthesizer: Rasgueado as a Case Study
This paper presents our research efforts to synthesize complex instrumental gestures using a score-based control scheme. Our specific goal is to simulate the rasgueado technique that is popular especially in flamenco music. This technique is also used in the classical guitar repertoire. Rasgueado is especially challenging as ordinary music notation is not adequate to represent the dense stream of notes required for a convincing simulation. We will take two approaches to realize our task. First, we use the practical knowledge of how the actual performance is accomplished by the human player. A second, complementary, approach is to analyze an excerpt from real guitar playing. Our main focus here is to extract the onset times and the amplitudes of the recoded gesture. Next we combine the results from the two analysis steps using a constraintbased approach to find possible pitch and fingering sequences. Finally we translate the findings to our macro-note scheme that allows us to fill algorithmically a musical score.