like to understand more, as still not digesting the need of capacitors. Can i ask followings : 1. How much RMS power 12" Subwoofers can Handle ? 2. For this power, what capacitors ratings are required to add ? 3. How much current exactly the amplifier drawing on this power ? We need to change the alternator in any case when we drive 1000Watts RMS, specially incase of Class A/B. Class A/B will draw 2500Watts of power, which comes to a 13.8Volts battery : 2500/13.8Volts = 181Amperes of current. More than a Welding machine outs. & This rating definitely exceeds the current drawn per second from battaery. So a capacitor would be required. Now it comes to a Woofer cone motion mechanics, the contineous power requirement at this moment lets say 75%, still 136Amps. Whta a alternator can produce is 136X14.5 = almost 2KWatts, driving a 1000watts practically requires an alternator change in any case. We are talking here about people having Grande or Linea, which comes an old technology, & these are looking for an upgrade of their ICE. These people are happy with output of the Stock ICE, but not with the stock speakers, & instead of changing the speakers they are guessing the stock HUs amp is also poor. becasue it can drive maximum a CD containing MP3s. These fellows also interested that MID shows the same kind of display too, with same centeral console looks. They are very narrow while upgrading the stock ICE, & we are talking here to change the alternator ? Like all 1DIN units out there in market, enough power is produced to match the hunger of a Punto. Amp is hardly advised here as no one wants to compromise on boot space. What Oval Speakers on Parcel Tray can handle is easily available in 1 DIN as well as in Stock HU. So I suggested to use these Bluetooth devices first which are cheap enough to give a try, I bet most of the people here get satisfied with stock HU with adding any of these bluetooth sets, SBH52 - Best One SBH 50 - MW 600 - SBH20 - Cheapest One Harman Kardon, iSub, Infinity Systems, JBL - are the same brands head by Mr. Paliwal - an Indian Bose - headed by another Indian Indians understand the sound engineering more than rest of the world. Dont you agree ? Writing these name here shows that not necessarily the Class D amps are very expensive. A BJT say 2N2055 is more expensive than an IRFZ44. Most of the BJT from Sanken for an AMP costs more than Rs300 whereas MOSFETS of 5 times rating costs only Rs.52. The power circuitry of Class A/B is also expensive to boost driving voltage to a certain level. Not getting understand where I am making a mistake ???