Sound Examples:   DIGITAL GUITAR BODY MODE MODULATION WITH ONE DRIVING PARAMETER

The following demonstrations were played as part of the presentation at the DAFx-00 conference in Verona, Italy, in December 2000.

The paper related to these demonstrations was published in the Proceedings of the 2000 COST-G6 Conference on Digital Audio Effects (DAFx-00), pp. 31-36, Verona, Italy, Dec. 7-9, 2000.

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 Henri Penttinen, Aki Härmä and Matti Karjalainen

Helsinki University of Technology, Laboratory of Acoustics and Audio Signal Processing


A warped guitar body filter can be modulated and controlled through one parameter, the warping cofficient . These soud examples examplify the modulation of the warping coefficient . The filter that is being modulated is a warped IIR (WIIR) filter with the order of 100.


Listen to these sound examples through good loudspeakers or headphones:

In the examples below the sound sources are an acoustic guitar with a bridge pickup OR an electric guitar used in the final samples .



Examples 1 to 4 are ACOUSTIC GUITAR EXAMPLES.

BASIC FILTERING Example 1: BASIC GUITAR BODY simulation filtering (*.wav files):

    1. A DRY signal from a bridge pickup on an acoustic guitar with NO filtering.
    2. STATIONARY body simulation filtering when = 0.756

STEPWISE MODULATION Example 2: STEPWISE modulation of the guitar body simulation filter (*.wav files):
                    In these samples is altered once: 1) Original value (0.73) to a smaller value (0.68).
                                                                            2) Original value (0.73) to a larger value (0.77).

                    When the value of  decreases the peceived size is reduced. When the value of  increases the peceived size is enlarged.

    1. STEPWISE   ORIG > SMALLER = [0.73   0.68].
    2. STEPWISE   ORIG > LARGER = [0.73   0.77].

CONTINUOUS MODULATION Example 3: CONTINUOUS modulation of the guitar body simulation filter (*.wav files):

    NOTATIONS:  I) = x     Indicates the value of the used warping coefficient.
                             II) = y    Expresses the peak to peak amplitude of the modified lambda.

    1. Sine-wave(1 Hz)= 0.756 = 0.1.
    2. LINEAR SWEEP (0.13Hz) (large triangle) with  values from 0.8 to 0.1 and back to 0.8.
    3. LINEAR SWEEP (0.13Hz) (larger triangle) with  values from 0.7 to -0.7 and back to 0.7.

Example 4: Highly flexible continious modulation of the guitar body filter (*.wav file):

    1. Sine-wave(4 Hz)= 0.5 = 0.1.



Example 5 to 6 are ELECTRIC GUITAR EXAMPLES.

STEPWISE & CONTINUOUS MODULATION

Example 5: STEPWISE & CONTINOUS modulation of the guitar body simulation filter (*.wav files):

    1.  ELECTRIC GUITAR
            At the very beginning of the sample a unfiltered a riff  played on an electric guitar can be heard. The second time the same riff is played basic guitar body simulation filtering is applied. After this the value of the warping coefficient is modulated stepwise. At the end of the sample the modulation is sinusoidal and at the very end a linear sweep can be heard.

    2.  ELECTRIC GUITAR: HIGHLY FLEXIBLE MODULATION
            In this sample the excitaton signal is the same as for the previous sample, but here the modulation is more dramatic.

Example 6: STEREO, STEPWISE & CONTINOUS modulation of the guitar body simulation filter (*.wav files):

    These samples are the same as exmaples 5, BUT are in stereo. The value of is sligthly different in the other channel. The difference in the value producess a stereo effect, but also affects the perceived location of the sound source.

    1.  STEREO ELECTRIC GUITAR

    2.  STEREO ELECTRIC GUITAR: HIGHLY FLEXIBLE MODULATION


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