What is the largest size wire the BPD1203 and Brahma12 can accept?

Discussion in 'Archived Threads 2001-2004' started by Anthony_Gomez, Aug 11, 2002.

  1. I looked on both of the sites, and I could not find the info. Anyone know? 12awg should be no problem at all, but what about 8awg?

  2. Shawn Solar

    Shawn Solar Supporting Actor

    May 12, 2001
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    Ha I just had my 1503 apart. looks like it will accept 10-8awg.
  3. Mark gas

    Mark gas Second Unit

    Mar 23, 2002
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    Why would you use 8 awg isn't that a little over kill
  4. it isn't when you are running a lot of juice over a distance and do not want any voltage drop (or almost none) or increased QTC
  5. Clay Autery

    Clay Autery Stunt Coordinator

    Oct 23, 2000
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    Anthony is right...
    I have just been working on the specs for a Looooonnnngggg DC power supply harness for a custom app with restrictive standards for voltage drop....
    The Voltage Drop equation is VERY unforgiving.... You'd be surprised how quickly you can get above a 1% (or 5%) voltage drop when you start stringing out the distance. AND in low voltage applications, voltage drop becomes even more critical....
    For instance... In the "factory" power harness, they used 18GA wire for the 5, 12 VDC rails and the harness was 18" (approx) long... To maintain the power supply performance criteria on a 6 foot power harness, I had to increase the size of the wires to 12 GA.... That is essentially DOUBLE the diameter...
    In speaker wire, I can't advise you as I am NOT an expert, but DC electricity is DC electricity...
    Question: What exactly ARE speaker signals... electrically I mean? Constant voltage? Variable current? Constant Current, variable frequency?
    Here is what I'd do...
    Find out exactly what the parameters are for the driving signals to my sub to include the voltage and current ranges... Frankly, the voltage range is the most critical... You need to find out what the macimum acceptable voltage drop is in the circuit from the amp to the driver... Then use the Voltage drop formula to solve for the required circular mils needed in the wire... Then find the exact (or next largest) wire size in the charts, and use that...
    Circular Mils = [2(D)(I)(10.8)]/Vd
    D = one way distance (in feet) in the circuit. The 2 is added to double the distance value since the entire circuit is nominally this long usually, and in speaker wire hopefully EXACTLY 2D.
    I = Maximum current (in amps) that could conceivably be placed into the circuit... I use the "max conceivable" value as a "safety margin" (READ: engineering overkill [​IMG]).
    10.8 = constant value for copper (cannot remember exactly what it is... I think it is an impedance constant in Ohms per like 1000' or something)
    Vd = maximum acceptable voltage drop (in volts) allowable in the circuit. For instance, on a 12Vdc circuit, if you can have a 10% drop maximum allowable, then the max Vd for that circuit is 10% of 12 Vdc or 1.2 Vdc. 10% is huge BTW... [​IMG] A DECENT power supply has less than 1% Vd in the harness and 1% regulation on the critical rails. I would think that with the low current demands on speaker signal circuits, you could likely get MUCH smaller voltage drops using relatively acceptable wire sizes...
    I'd REALLY like to know the electrical descriptions for speaker signals.... [​IMG]
    When in doubt, (my opinion) use the largest gauge wire that the application will accept. Note... on internal speaker wiring.... especially crossovers, I would suspect that changing the wire gauge may/will cause changes in response/impedance curves, etc... But, on speaker wire it would be my opinion that the bigger the better essentially as a speaker wire can only damage the signal.... The IDEAL speaker wire length would be ZERO thus introducing no change to the signal... Thus, anyhting you do that can make the speaker wire less of an electrical factor, would seem to be what you are looking for.... of course there are other factors like capacitance, inductance, etc, etc...
    Anyway... hope this helps..

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