Over the past decade, spatial audio awareness evolved into an in-demand feature in audio entertainment. The addition of sound source locations to, for instance, movies or music adds a level of auditory envelopment and spatial awareness to the audio experience. Expensive setups present in, for instance, cinema's, are able to create this envelopment by means of a large set of loudspeakers with which the desired sound fields are created. Creating this spatial envelopment in practical consumer living rooms or home cinema setups proves to be a more challenging task due to the impractical amount of loudspeakers required. To create the audio envelopment with a small amount of loudspeakers, crosstalk cancellation can be used. Crosstalk cancellation as posed in literature is, however, not robust enough to be used in practical appliances. The main cause of these bad characteristics is the objective cost function it optimizes which results in an ill-posed problem. In this thesis, the crosstalk cancellation problem is relaxed by aiming for perceptually sufficient results instead of aiming for objectively optimal results. The human auditory system has its limitations in both the perception of audio and localization of audio sources. Exploiting the limitations of the auditory system generates mathematical freedom that can be used to construct a more robust and stable crosstalk cancellation algorithm. This thesis provides the first steps towards the incorporation of audio perception in the domain of crosstalk cancellation and audio envelopment with a limited amount of loudspeakers.

This thesis report focuses on possible methods of digital implementation of motional feedback in a bass loudspeaker. In this thesis, the control system will be created for a monopole and a dipole speaker specifically. It does so by sketching the outlines of such a system and examining possible designs for the components required to suppress distortion which is mainly created by the speaker. This thesis shows that the digital implementation indeed allows filtering with very little latency but there are limitations in accuracy due to the conversion from the analogue to the digital domain. It is shown in this thesis that a partly analogue and partly digital system is desired for better error correction. A desired input-output gain of 30=29.54dB is achieved. The controller that is suggested is a controller based on the transfer function of the speaker. By transforming the input signal with the inverse of this open-loop transfer, the closed-loop transfer will be flattened. The instrumentation amplifier used to subtract the feedback signal from the input signal is designed such that the influence of the quantization noise is minimized. Loop-gain is added by the instrumentation amplifier, the controller and voltage-to-current amplifier. By creating loop-gain as much as possible using the digital implementation, noise is suppressed from 30dB up to 90dB within the range of frequencies of interest. The designed components in the motional feedback system allow a loop-gain up to 70dB and an input to output voltage gain of 30dB before instability occurs.