the high level input is usually a harness that plugs into your amp.. your supposed to directly wire from the head unit to the amp.. and then to the speakers.. but yes its ok to use the RCA's for speakers.. usually depending on the amp
http://akamaipix.crutchfield.com/pro...236t282-i.jpeg
i think he means like that.. on the right there are the speaker level inputs or high level inputs.. they can only be used forspeakers reguardless of a lpf or anything.. trust me.. i messed up my jbl subwoofers that way hah.. and the "low level" are the rcas.. but it should be ok.. you can either turn it to high pass or all pass and it'll play normally.. you shouldn turn it to low pass if ur using rca's... and your powering speakers