addition of capacitor for ice power supply.::O yes we face the issue of head lamps dimming ,distorted sound at heavy bass thumps. the solution is power supply conditioning. enquired about a 1 farad reservoir capacitor , it was expensive and rarely available . so i thought of DIY it. the pic is 20x4700 micro farad 25volt keltron capacitors in parallel.( 10000micro farad was prefered but again unavailable) that is 94000 micro farad total, almost near 1 farad that should be enough to notice some change.. now it need a suitable cover.i wrapped it in a vinyl sheet and taped. diy capacitor have been installed ,connected parallel to subwoofer amp. (sadly that made only 0.94 farads. not enough upto my expectations.) light dimming has been reduced considerably. earlier at volume level of 16 head lamps would be dimming along with bass thumps. now i can go as high as 24th level. sounds cleans without distortion. beyond 24 it does distort . but with that much sound my eardrums are already about to blow up so no worries for time being. the oem HU have volume level upto 40 . pic , the capacitor must be connected closest to amp with minimum length of cables. please note the capacitors does not improve power of your batteries or alternator so do not expect higer power. what capacitor does is it compensate for voltage drop across the cables and instant surge requirement for bass thumps so more farads the better to an extend. sometimes later i would be upgrading to 3 farads or 5 farads. total cost 20 capacitors=18x20=rs.360 common pcb=rs.20 wiring =rs.10 my labourcharge =priceless satisfaction!!!