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Understanding amps?

Discussion in 'Audio & Video' started by Jpf8653, Aug 19, 2009.

  1. Aug 19, 2009 at 6:13 PM
    #1
    Jpf8653

    Jpf8653 [OP] Well-Known Member

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    I cant ever seem to figure amps and wiring out. I thought i understood but may have confussed myself.

    Ok If u have 2 dual 4ohm subs and your wiring up to a mono amp would wiring it to 1 ohm load be the most efficient or 4 ohms?
    \
    Next same subs. Rated for 400 watts RMS each. Would a 500 mono amp be enough? Or would u want to run an 800 or more?
     
  2. Aug 19, 2009 at 6:31 PM
    #2
    Jpf8653

    Jpf8653 [OP] Well-Known Member

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    Also what amps can be wired to .5 ohms?
     
  3. Aug 19, 2009 at 6:32 PM
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    stang88

    stang88 Well-Known Member

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    yes.. 1 ohm is the best load for a 1 ohm stable monoblock amp.

    i would choose the 800 watt amp.
     
  4. Aug 19, 2009 at 6:33 PM
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    stang88

    stang88 Well-Known Member

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    many old cheater amps can. you dont find too many nowadays that go to 1/2 ohm.
     
  5. Aug 19, 2009 at 6:38 PM
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    PSUnick

    PSUnick Lets Go State!

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    You have two subs that are 400W, 4 ohm each, each dual coils. To hook them up to a mono amp, you need to wire them in parallel. This will drop the effective impedance to 1 ohm.

    Look at the specifications for the output power of your amp at 1 ohm. If the amp is rated for 800W at 1ohm, then you will be providing 400W to each sub. If the amp is rated for 500W at 1 ohm, then you will be providing 250W to each sub.
     
  6. Aug 19, 2009 at 6:41 PM
    #6
    Jpf8653

    Jpf8653 [OP] Well-Known Member

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    I thought the 800 also, guy at the audio shop said 500.
    /
    I didnt realize not all monos could handle the 1 ohm. thanks all makes since
     
  7. Aug 19, 2009 at 6:42 PM
    #7
    Jpf8653

    Jpf8653 [OP] Well-Known Member

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    That i understood thanks for the reassurance!!
     
  8. Aug 19, 2009 at 6:57 PM
    #8
    Jpf8653

    Jpf8653 [OP] Well-Known Member

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    So pretty much i had my last setup all wrong?

    (1) Dual 2ohm wired to a mono block that didnt do 1 ohm. had one positive to the opposing negative and the other two run to the amp.
    thats a 4ohm load and gives less watts. had a 500 watt RMS sub on a 600 block and wasnt giving it enough watts with this setup Correct???
     
  9. Aug 19, 2009 at 7:22 PM
    #9
    KAPendley

    KAPendley Best Hack I Know

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    The question I have is what subs do you have? And if you already have an amp, what amp is it.

    A 1 ohm load WILL produce more power, but the efficiency of the amplifier falls off dramatically, and it will also require more current. Here is an example...with a twist.
    The Arc Audio 500.1. The reason is you can download the tech sheet on the amplifier and it gives you the efficiency rating at the ohm load it is receiving, but this amp does the same power at 1 AND 2 ohm, and does not lose much more power at 4 ohm, yet the efficiency of the amp, and the current draw is much, much better.

    Power output @ 4 ohms 450 watts RMS @ 44 Amps 75% eff.
    Power output @ 2 ohms 600 watts RMS @ 65 Amps 68% eff.
    Power output @ 1 ohm 600 watts RMS @ 78 Amps 53% eff.

    Now if you notice the current draw, on a stock charging system, at 1 ohm, the amp WILL NOT produce 600 watts. It would be more around 475-500 (VERY rough guess, could be more) because it is doubtful your car would be running more than 60 amps to power ALL your electronic systems. The amp is also rated to do this at 14.4 volts, so that, of course, is when the vehicle is running at optimum, not at idle, when the battery is only 12.3-12.6 volts (more or less, on a good battery)

    Arc amps are a bit underrated though. When tested the output is usually 30-50 watts more. So you get more for your money.

    Sorry I am so biased, but it is good to use them for a reference as I am very familiar with the product. lol.
     
  10. Aug 19, 2009 at 7:30 PM
    #10
    Jpf8653

    Jpf8653 [OP] Well-Known Member

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    ok lets forget what i had i already sold it.

    Im getting a rockford fosgate p3 shallow. It is one thats preloaded. comes in the rockford marked box. It has been prewired for 4ohms. The speaker is a dual 2 ohm. 400 watts rms. I was going to get it and get a Punch 500.1. Then rewire for 1 ohm since it only buts out like 200 watts at 4 ohms. and the sub cant be wired to 2 ohms.
     
  11. Aug 19, 2009 at 7:31 PM
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    KAPendley

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  12. Aug 19, 2009 at 7:35 PM
    #12
    KAPendley

    KAPendley Best Hack I Know

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    Try running the sub at both ohm loads. You may be surprised by the output. Amps get hot at 1 ohm.....so its worth the try at 4 ohm...IMO.:)
     
  13. Aug 19, 2009 at 7:36 PM
    #13
    Jpf8653

    Jpf8653 [OP] Well-Known Member

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    Were u going for let the professional do it? They are the ones that confused me. They want to run 2 P3s on only a 500.
     
  14. Aug 19, 2009 at 7:51 PM
    #14
    KAPendley

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    Not at all. If you get the sub, and it is a dual 2, you can wire it for a 4 or 1 ohm load. If it was dual 4, you can only get 8 or 2 ohms.

    You could run 2 of them at 2 ohms, because 4 and 4 parallel equals a 2 ohm load.:eek:
     
  15. Aug 19, 2009 at 7:55 PM
    #15
    Jpf8653

    Jpf8653 [OP] Well-Known Member

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    Right, but now im only putting 200 watts to each speaker with my 500 watt amp. cause at 2ohms it rated at 400 watts RMS

    Im sorry but the earlier response was the only thing i found on page 2 referring to what were talking. " let the professional do it"
     
  16. Aug 19, 2009 at 8:02 PM
    #16
    KAPendley

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    Oh yeah, forgot that part. Also forgot to go back and edit and say pages 2-4. LOL. Sorry. The Arc manual simplifies things, and thats is what I was hoping would help you out. :D I guess you know more about what you are doing than I had previously thought.
    Doing my best bro, bare with me.
     
  17. Aug 19, 2009 at 8:09 PM
    #17
    Jpf8653

    Jpf8653 [OP] Well-Known Member

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    Well i was fine with what i know until yesterday when the guy wanted to do what i said a min ago and put 500 on two 400 speakers. I saw u use to own a shop so i figured id try and get all the help i could before i go back and called the guy i talked to a stupid MTF.
    I do thank you though for the help. keep it coming though i like knowledge.
     
  18. Aug 19, 2009 at 8:26 PM
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    KAPendley

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    I wasnt a RF dealer, so I had to check their site for the specs. According to RF, the sub is 300 RMS, 600 Max. So I would NOT push 500 watts to ONE sub. You would really be pushing the limits of what it can handle. That guy was actually keeping you in a pretty safe zone, and it would not be a bad idea to slightly under power a shallow mount sub. You would not want to reach its excursion limits, and a shallow sub just does not have much throw to it.
     
  19. Aug 19, 2009 at 8:33 PM
    #19
    Jpf8653

    Jpf8653 [OP] Well-Known Member

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    Not sure we are looking at the same thing.


    http://www.rockfordfosgate.com/prod...ly_id=55&item_id=108284&locale=en_US&p_status=
     
  20. Aug 19, 2009 at 8:44 PM
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    KAPendley

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    You are correct sir. We never discussed what size, so I just assumed it was the 10.
    Yeah, I would want AT LEAST 600-700 watts rms. My apologies again. HAHA.
     
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