immortal1 (linn)
+1y
^Not really... Part of the problem with an under powered system is the gain level on the amp gets adjusted to high in an attempt to get more sound. Part of the job of the amplifier is to CONTROL the motion of the speaker. If the amp asks for mote power than is available, you get what is called "clipping" or in other words, the amp loses control of the speaker at its outer or inner most points of motion (distotion of sound). A setup that includes a 200 watt sub and a 400 watt amp typically will perform better that a 400 watt sub connected to a 200 watt amp.
In your situation, if you build a bandpass box, you will not be able to clearly hear the sub distorting and will probably end of with a damaged sub (not a burned out voice coil).
Keep your current box, use the KAC-748 to run front & rear mids/highs and get a separate amp for the sub.