Question about wiring MM840DVC to the amp.

Milenko2121
Milenko2121 Posts: 6
edited March 2012 in Car Audio & Electronics
Never had a dual voice coil before and my Polk PA400.1 amp has two pos/neg outputs.

I was wondering do I hook up (Pos+ 1 on the Subwoofer) to (Pos+ 1 on the Amp) And (Pos+2 on the sub) to (Pos+2 on the amp)?

or Is is (Pos+1) to (Pos+2) connected together on the Subwoofer and then connected to (Pos+1 on the amp)?

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My other question is, is this PA400.1 amp good enough to power two MM840DVC's in a sealed box?
What would be the best way to connect them, Series or Parallel?

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Last question is this
What box size would be best, 0.35 cubic feet or 0.50 cubic feet for the sealed box? it says it's good for those sizes, just never really knew the difference of using either.
Post edited by Milenko2121 on

Comments

  • arun1963
    arun1963 Posts: 1,797
    edited March 2012
    A mono amp is one channel only. The two sets of +/- are only for the convenience of hooking up two subs individually. Internally, its wired for one channel. So you can use any +/- while hooking up the sub.

    The PA amp will put out more watts on a lower impedance. So wire your two subs in parallel to show a 2 ohm load and each sub will get 150 watts.

    How loud your sub plays, is determined by the distance the cone can move. You want the sub to be able to move to its max linear excursion, not it's physical limit (Xmax). That distance is determined first by the box size. Too small and you will limit excursion, too large and you run the risk of letting the sub go beyond its linear limit. With a small box you can use more power to get the excursion higher, same as making the box slightly larger with lower power. On 150 watts I would go slightly larger than recommended specs. Probably around 0.6cuft.

    Hope I haven't confused you. This is a link to a great site for a lot of basic technical questions that you may have.

    http://www.bcae1.com/
  • ipartywhenuhurt
    ipartywhenuhurt Posts: 130
    edited March 2012
    you need a bigger amp for i dont think the 400.1 is stable at 1 ohm for u have two dvc which are dual 4 ohm which makes them either 2 or 8 ohm depending on how u wire the sub

    if u parallel the 8 ohm u get 4 ohm which is not enough power and if u parallel 2 ohm u get 1 ohm which your amp wont work at, it will over heat to fast

    and if u series the 2 ohm u get 1 ohm which again is not enough

    that amp will only work for one of ur subs at 2 ohm giving the sub 300 rms witch is good for the sub rated at 250 rms and a little leway
  • ipartywhenuhurt
    ipartywhenuhurt Posts: 130
    edited March 2012
    u need at least a 500 rms amp stable at 4 ohms or 2 ohms depending on how u want to wire the subs
  • Milenko2121
    Milenko2121 Posts: 6
    edited March 2012
    My manual states its 1ohm stable at 400rms which would give me 200rms each. The subwoofers say they're rated at 180rms.

    How do you wire them down to one ohm using a dual sealed box? Can I hook up both in parallel the same way I'd hookup a single one? Just mirror the connection using Pos+1 for sub1 and then Pos+2 for sub2 or do I need to wire Sub1 and sub2 together?

    Pos1 and 2 refer to my amp connections.

    I was thinking that 0.4cu per chamber would be enough with 200rms each or should I go bigger?
  • ipartywhenuhurt
    ipartywhenuhurt Posts: 130
    edited March 2012
    1.) wire ur sub's each to 2ohms since there dual 4 ohms ur manual should tell you how
    2.) after that ur amp should have 2 positives and 2 negative speaker connections.
    hook each sub to one positive and negative like this - -+ + the S are sub one and T is sub Two
    ^^^^
    s tS T
    - -+ +

    or hook the subs inside the box, connecting the + with + and - with - so you have only one wire coming from out of the box to the amp. then you can pick a positive and a negative u like at the amp with the single wire from the box
  • ipartywhenuhurt
    ipartywhenuhurt Posts: 130
    edited March 2012
    and if thous are the specs then you should be completely fine and happy
  • Milenko2121
    Milenko2121 Posts: 6
    edited March 2012
    thanks for the help :D

    last question for now, i'll be building the box tomorrow.

    In my manual, it states the recommended box size is 0.35cu ft. Is that including the driver displacement because it does not give me the displacement of the subwoofer in my manual.
  • Milenko2121
    Milenko2121 Posts: 6
    edited March 2012
    ok, i guess i have anther question that's getting highly confusing.

    my book says reccomened size is 0.35cu ft, but online it's saying 0.68cu ft: source (http://www.polkaudio.com/caraudio/subbox/subbox_plan.php?id=115&mesurements=standard)

    however those specs are different than my manual...

    I just wish I could know the exact volume to make my box for the best possible sound.