This paper deals with active noise control (ANC) on a broadband frequency range for a 3D-cylindrical cavity closed on two sides. A 1D acoustic model is first derived by averaging the pressure on surfaces that are perpendicular to the acoustic propagation direction. Based on the novel analytic model proposed, robust Multi-Objective Hinfty control (MOHinfty) is considered to explore the possibilities of noise attenuation not only at the error signal got from the microphone, but around. The SISO feedback control scheme considered (one microphone measuring the residual noise and one loudspeaker) has no direct information on the disturbance noise. Within this framework, the achievable attenuations both with regard to frequency and to space are discussed.