I have a set of infiity kappa perfect set to HP and the amplifier for my sub is set to lp ... I need to know what are the best settings which include the bass frequency and LP frequency. an anybody help ? I have my bass boxset to 40hz.
That is the bass freq, the subs won't pick up anything above 80hz.
If you mean that your box is ported to 40hz, which is a really high freq for everyday driving, then you will need to get a subsonic filter that blocks all frequencies under 40hz, otherwise you could damage your sub. You can buy them on ebay for around $20-30 I believe.