PSI Audio AVAA C20 - Active Bass Trap System (Black)Unique: easy to set up and move, no calibration required, as efficient as passive absorbers 25 times its size, the AVAA C20 typically reduces the resonance time of all room modes between 15 Hz and 150 Hz by up to 50%. Features: High efficiency As effective as a perfect passive absorber up to 25 times its size 100% analogue No DSP is used. Its 100% analogue technology allows a zero latency processing. Works in any type of room The AVAA C20 can be used