Speaker cabs and room simulations using computational models
If you place a speaker anywhere in a small room, is it possible to calculate how it will sound at a chosen listening position?
In an attempt to answer this question, an automated computational concept has been developed. Using two parametric acoustic models, the spectra of the cabinet and room responses can be calculated. The resulting transfer functions form the basis for computationally based loudspeaker cabinet and room plug-ins.
If the calculated responses are sonically good enough, we can bypass both the time-consuming process of recording loudspeaker responses and the inherent sequence of transfer functions.
So will the calculated response of the virtual speakers be different, good or bad, compared to the measured response used by most cabinet plugins? Below is a guitar and bass track using CabSolver. The settings emulate two cabinets at different locations in a small room (there is no post-processing here, just raw track data).
Some about the acoustic models
Due to the rather complicated physical nature of a loudspeaker and cabinet arrangement (we are dealing with a double transducer), a pragmatic modelling approach is used to account for these energy transitions (electrical -> kinetic -> acoustic ).
The loudspeaker and cabinet model is based on a few parameters (some are more useful than others). I use the model to solve the acoustic near field problem, i.e. to calculate the pressure response valid for an arbitrary location near the loudspeaker.
A similar modelling approach is used for the room model, a model based on a few room and loudspeaker related parameters. The focus here is on the corresponding far-field solution to the acoustic problem, i.e. I try to relate a chosen loudspeaker position to a stationary 'receiver' in a small room. The acoustic solution thus gives the transfer function for the room setup.
By a simple merging procedure, the extracted far-field and near-field results can be combined to get what I am looking for, a response that represents a kind of 'cab-in-a-booth' sound.
A short track based on the cab & booth plugin, CabOne.
An old PowerPoint presentation including some additional information about the cabinet and room modelling.