Digital active bass trap The AVAA C214 eliminates excess bass resonances from 15 Hz to 160 Hz with unmatched efficiency.Its compact design hides a huge absorption power – 45 times its actual size. No calibration, no measurements – just plug it in and enjoy perfectly controlled bass. The effective solution against room modes Based on the same absorption principles as the AVAA C20, the AVAA C214 is fully digital and allows control via an app.Please note that it is NOT A PHASE CANCELLATION device. Working from 15 Hz to 160 Hz The AVAA is pressure based absorber.Whether you have 1 or multiple disturbing room modes, the AVAA C214 will absorb all of these that are present in its location. No calibration required Simply place it where your room modes are and it will absorb them. No calibration required.