"Weak subwoofers employ limiters (ie high-pass filters) to ensure that they don't self-destruct. This prevents bottoming out, longer life, etc. Some subwoofers don't necessarily need subsonic filters, like small sealed subwoofers, which act like pseudo high-pass filters."
Ok so I read-up on the subject and pretty sure my avr model can't help me. However finding and instaling the rite external hpf is of importance before sealing my SId4.
Where can I find a good filter where and how do I do the install? Anything else I should know? Martycube 17hz tune. thank you guys for your input : )