@MASTERSTHESIS\{IMM2005-03871,
    author       = "M. R. Andersen",
    title        = "Compensation on Nonlinearities in Transducers",
    year         = "2005",
    school       = "Informatics and Mathematical Modelling, Technical University of Denmark, {DTU}",
    address      = "Richard Petersens Plads, Building 321, {DK-}2800 Kgs. Lyngby",
    type         = "",
    note         = "Supervised by assoc. prof. Ole Winther and assoc. prof. Jan Larsen. In corporation with {\O}rsted.{DTU} and Oticon a/s",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/3871-full.html",
    abstract     = "This thesis is concerned with the topic of compensation algorithms for the nonlinearities in transducers for use in hifi-loudspeaker. The thesis contains a examination of the general ideal loudspeaker model. Furthermore, nonlinearities that influences the performance of the loudspeaker are described, and measurement are done on what they does to the loudspeaker.

The loudspeaker model is from here transformed into the digital domain, in preparation for constructing a control system later. In order to make this model complete, appropriate functions are fitted to the nonlinearities and added to the model. 

Furthermore, a text based toolbox for Matlab is made for simulations and evaluations of di erent properties in both the loudspeaker and in the upcoming compensation algorithm. 

Finally, two interesting feedforward controller systems are presented. The first is the  {''}state space{''}  compensator and the second is the {''}Mirror filter{''} derived by Wolfgang Klippel. Later research has shown that they are of same controller type. 

In Danish:

Denne rapport omhandler emnet kompenserings algoritmer for ikke-lineariteter i transducere til brug i hi-fi h{\o}jttalere. Rapporten indeholder en gennemgang af den generelle ideelle h{\o}jttaler model. Yderligere er ikke-lineariteterne der forringer ydelsen af h{\o}jttaleren beskrevet og m{\aa}linger, omkring hvad det g{\o}r ved denne, er foretaget. 

Herfra overf{\o}res h{\o}jttaler modellen til det digitale dom{\ae}ne med henblik p{\aa} senere at konstruere et regulering system til denne. Og for at g{\o}re modellen komplet i forhold til h{\o}jttaleren, tilpasses en passende funktion til ikke-lineariteterne s{\aa} disse kan inkluderes. 

Desuden pr{\ae}senteres en Matlab toolbox til hj{\ae}lp med at simulere og evaluere de forskellige egenskaber i b{\aa}de h{\o}jttalere og ogs{\aa} i de senere kompenseringsalgoritmer. 

Til sidst gennemg{\aa}s to interessante prekompensering algoritmer. Den ene er  {''}state-space{''}  kompensatoren og den anden er Wolfgang Klippels {''}Mirror filter''. Ved senere tids forskning har det dog vist sig, at disse to er af samme type reguleringssystem."
}