Wiring with capacitors

Discussion in 'OT Technology' started by Pinan, Oct 4, 2003.

  1. Pinan

    Pinan pagan holidays > * other holidays

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    Here is the scenario.

    Rockford 4 channel amp (dunno what model, it belongs ot a friend) that I believe is in the neighborhood of 45 x 4 rms (rated). front 2 channels going to kappa 6.5 in the front, and the same in the rear. Car has locations for additional 4" speakers.

    He would like to utilize the 4's, but I need to verify what I am relaying to him. The front channels of the amp can handle 2 hom stereo, so run the 4 and the 6.5 off of it (parallel). Put a cap inline to the 4. 2 reasons. 1. passive crossover to riase the midbass crossover point on the 4 (gonne be running high pass off of the amp, so it will already by crossed over, just too low. 2. Passive crossovers absorb power, and the 4's have a lower power handling satbility. Im figuring if the amp does (rated) 45 x 4 at 4 ohms, it should do 80 - 90 rms at 2 ohm, so the 6.5 will get 40- 45 rms, while the 4 will get ~20 - 25.

    Been awhile since I messed with this end of the spectrum. Is this accurate? Or any other suggestions? The equip (except the 4's) has been purchased already, so a change in the hardware isnt an option. The sub will be a perfect 12 off of a 300w rms (roughly) fosgate as well.
     
  2. twistid

    twistid Banged By Super Models Moderator

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    why not just run the 4"s off the headunit, and use the amp for both sets of 6 1/2"s???
     
  3. boostin-gp

    boostin-gp Guest

    :werd: that is exactly what i was gonna say
     
  4. Pinan

    Pinan pagan holidays > * other holidays

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    Main reason is that he is insisting on running the whole thing off of the stock headunit. Yeah, I know, but he lives in a crappy area, and figures if there is anything visible, its gonne get lifted.

    Plus,

    The one time that I tried to run one set of speakers off of the head unit, and another off of the amp, the sound was strange.
    Meaning, that the headunit went from 0 - 40 on the volumne. At 30 or so down, the ones off of the factory unit outdrove the amped ones, but from 30 up, the amp WAY outdrove the head unit ones. The head unit was a MobileES, and it was in my personal car.
     
  5. 04

    04 Guest

    I wouldnt really reccomend using a first order passive filter like only a cap in series, as you get peaking below the filter's cutoff frequency, and it really doesnt do much good. The capacitor won't "absorb" much power above its target frequency, as it will appear as close to a dead short, so you can figure that the speakers will be getting full power at frequencies above that.

    I really reccomend you don't go with the 4" speakers, and just run the 6.5" with the active highpass crossover on the amplifier set somewhere around 100hz or so.
     

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