Kc i just installed an amplified subs on an altis with a pioneer HU... i installed it myself and everything is fine pero nung tinetseting ko na napansin ko na after mga super lalim na bass may motor boating po ung subs... (ang sabi nung sub - bog - bog - bog -bog - bog) tpos kapag ung volume binaba ko sa zero and increase it again nawawala ung motorboating... it always just hapen pag sobrang low ng bass kc pag mga normal and rock music wala pero pag ka mga rnb and bass music lumalabas talaga... d ko alam kung ano po ang culprit eh... baka meron pong naka encounter na ng ganitong problem and pwede makatulong... maraming salamat po...

And by the way... a little more info para mas malinaw... ung power cable nug subs pinadaan ko sa driver side and ung signal from HU and remote dumaan sa passenger side.