MIMO swept sine excitation is nowadays largely used in environmental and modal testing of aerospace structures, being recognized as an optimal compromise between high quality FRFs and testing time. Due to the test levels that can be reached, monitoring the recordings of multiple transducers translates in the need of on-line controlling the signals, in order to keep them at a (safe) reference level. At the same time, FRFs obtained from MIMO sine tests can also be affected by the processing technique used to combine multiple sweeps. In this paper, a feed-forward control strategy for MIMO sine testing aiming to reduce the error between the responses and the references is presented. This approach moves towards a MIMO swept sine feedback control, with the capability of on-line modifying the model of the system obtained in a pre-test phase. Subsequently, with focus on Ground Vibration Testing, an advanced data processing technique is used to obtain an optimal modal model from the multiple sweeps.