Body Factoring Example

Figure: Impulse response of a classical guitar body before and after removing the first peak (main air resonance) via the inverse filter defined by Eq.(S.1), with and .

Figure S.3: First eighth of Figure S.2.

Figure S.2a shows the impulse response of a classical guitar body sampled at kHz. It was determined empirically that at least the first msec of this impulse response needs to be stored in the excitation table to produce a high quality synthetic guitar. Figure S.2b shows the same impulse response after factoring out a single resonating mode near Hz (the main Helmholtz air mode). A close-up of the initial response is shown in Fig. S.3. As can be seen, the residual response is considerably shorter than the original.

Figure: Normalized amplitude response of a classical guitar body before and after inverse filtering via Eq.(S.1), with and .

Figure S.5: First eighth of Figure S.4.

Figure S.4a shows the guitar-body amplitude response, and Fig. S.4b shows the response after the main Helmholtz air mode is removed by inverse filtering with a two-pole, two-zero filter. Figure S.6 shows the same thing but with only a two-zero inverse filter; in this case the overall spectral shape is more affected.