cap questions

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Comments

  • deepinya
    deepinya Posts: 199
    edited April 2006
    so you are telling us to trust sale people?!?!
  • PoweredByDodge
    PoweredByDodge Posts: 4,185
    edited April 2006
    FYI...

    1- you're going to draw about 130 amps... depending on how long of a wire run you have, you'll need 2 gauge power and ground lines... or (for a longer run) 0 gauge.

    2- my reccomendation... 1 to 2 farads... i used to be happy with the "1 farad per 750 watts" rule of thumb.

    3- good quality, low electro static resistance caps will discharge faster than lead acid or gel cell batteries (that includes yellow tops). This means that they will in fact supply "juice" to the amplifiers faster than batteries could. That is all a moot point however, since it's not why competitors in SPL are swaying away from capacitor use. It's skewing the topic... so lets get back on topic.

    4- caps are being discarded from SPL high power use because the "3 second burp" is way too long to be sustained by a few caps. Hundreds and hundreds of farads would be necessary to sustain a 10 or 20 thousand watt audio system for 3 seconds (on batteries and alternator and caps). The problem is... and we'll put this simply for the sake of keeping me from slitting my wrists here... during that 1st second, the capacitors are stiffening half a volt or so to the amplifiers (if the electrical system is built properly)... well they discharge down to 12.5 or 13 volts due to that insane draw during that 1st second... well now during the 2nd and 3rd seconds the caps are trying to recharge themselves... so they're actually taking power AWAY from the amplifiers so that they can recharge to 14.4 or whatever the alt is putting out. And this is why caps are "bad" for SPL competition... given ENOUGH capacitance, they would be GREAT! But who's got room for 500 farads of legitimate capacitance... and i'm not talking those piece of **** Pyle "500 farad" caps that look like a shoe box.
    The Artist formerly known as PoweredByDodge
  • MacLeod
    MacLeod Posts: 14,358
    edited April 2006
    3 second burps?!? How about 1/2 second! SPL burps are extremely short.

    MECA's SPL classes are rated by fuse rating rather than amp rating so you have guys with a million watts trying to force it thru a 30 amp fuse. And it works too, for about a half a second and then poof!
    polkaudio sound quality competitor since 2005
    MECA SQ Rookie of the Year 06 ~ MECA State Champ 06,07,08,11 ~ MECA World Finals 2nd place 06,07,08,09
    08 Car Audio Nationals 1st ~ 07 N Georgia Nationals 1st ~ 06 Carl Casper Nationals 1st ~ USACi 05 Southeast AutumnFest 1st

    polkaudio SR6500 --- polkaudio MM1040 x2 -- Pioneer P99 -- Rockford Fosgate P1000X5D
  • PoweredByDodge
    PoweredByDodge Posts: 4,185
    edited April 2006
    regardless of time length, you get my point -- the caps do their job, discharge, and then suck amperage away from the amplifiers trying to recharge themselves.
    The Artist formerly known as PoweredByDodge