Line source's lean design is that energy in the low and low-mid ranges is almost equally strong both in front of and behind the speakers. On the one hand, this dipole effect increases the risk of feedback during live performances on stage. On the other hand, the diffuse rear sound parts worsen speech intelligibility. To counteract this, the sound engineer needs to considerably equalise the feedback-prone frequencies with conventional line sources. The result is a pressure-free, thin sound. This is exactly where the VIDA C module comes into play: Using the cardioid module is the ideal solution. It counteracts the dipole effect of the line array with up to 20dB rearward attenuation in the range of 60Hz to 400Hz.