Body-Model Factoring

In commuted synthesis, it is often helpful to factor out the least-damped resonances in the body model for implementation in parametric form (e.g., as second-order filters, or ``biquads''). The advantages of this are manifold, including the following:

• The excitation table is shortened (now containing only the most damped modal components).
  
• The excitation table signal-to-quantization-noise ratio is improved.
  
• The most important resonances remain parametric, facilitating real-time control. In other words, the parametric resonances can be independently modulated to produce interesting effects.
  
• Multiple body outputs become available from the parametric filters.
  
• Resonators may be already available in a separate effects unit, making them ``free.''
  
• A memory vs. computation trade-off is available for cost optimization.

Techniques for carrying out this factorization in practice are discussed in §8.8 [230].