How is power "shared " between cabinets

Discussion in 'Amps and Cabs [BG]' started by Speedbird, Aug 9, 2000.

  1. Speedbird

    Speedbird Supporting Member

    Jul 10, 2000
    Northern Virginia
    Simple problem, I want it all. Using a medium sized power amp (Crest CA-6) and 2 cabinets like a 1x10" and a 2x12" (Epiphani). I want to use only the small cab at home, or slpit the cabs for practice (bass through one side, drum machine through the other) then bridge the amp for max power at full volume jams and gigs. I under stand the ohm thing but not how the power "consumed", so here are the questions: (lets assume all power levels are peak, the power amp (like most) can handle 2ohms/channel and 4ohms bridged, and the cabinets can be ordered in 4 or 8ohm)

    -Can two 600 watt cabs in parallel handle 1200 watts?
    (I think so but am not sure.)

    -Can two 600 watt cabs in series handle 1200 watts?
    (I don't think so since the whole signal must pass through the first cab to reach the second)

    -Is it possible to drive both a 300 watt 1x10" and a 600 watt 2x12" to their max from a single channel?

  2. Scok


    Apr 20, 2000
    Either way you hook up your amps, they are wired in parallel. You can only wire them in series by opening up the cabs and chaining all the speakers toegther (not recommended. :)

    If your running both cabs off a single channel, your 10 will distort and possibly fry before your 12's do.
  3. Both parallel and series connections do allow (2) 600 Watt cabs of equal impedance to equally share 1200 Watts. You are correct. And you would have to make a special cable setup to series them. And the amp would have to deliver 1200 Watts into 2 different impedances, like 4 and 16 if the two cabs are both 8 ohms.

  4. JimM


    Jan 13, 2000
    Northern California
    I think you need to take into account each cab's sensitivity.If they are very different,and I bet they are,You may not gain anything by adding a 10 to 2 least it may not be audible.Adding a cab may reduce the impedence and thus increase the output wattage,but the cab that moves the most air,the 2x12,may have less wattage applied to it.Hope I didn't misunderstand the question.
    Try before you buy.If possible,take your bass and amp to somewhere that has the set-up you want and A/B them to see.
  5. rcrimm

    rcrimm Commercial User

    Jun 20, 2000
    Meridian, MS USA
    Customer Service, Peavey Electronics
  6. Matthias


    May 30, 2000
    Vienna, Austria
    To summarize this and the comment of JimM:

    If the 1x10 is rated at 8Ohms and the 2x12 at 4 Ohms, the output power of the amp will be distributed according to their rated wattage and you will theortically get the most out of each cab.
    BUT: the 1x10" gets less power AND has less speaker area, this means it's output will be much lower than the 2x12's, wich means you won't hear the 1x10.

    Conclusion: It will hardly make a difference if you add the 1x10 or not.

    So far so good, here comes MY question:

    If you look at the system from another point of view, you can say that adding the 1x10 means increasing speaker area by 35% and increasing the power output due to the lower impedance.
    This should make a clearly audible difference in volume!

    What's right???????
  7. rcrimm

    rcrimm Commercial User

    Jun 20, 2000
    Meridian, MS USA
    Customer Service, Peavey Electronics

    Ok, lets say that each of the drivers in the system (the 10" and the two 12's) are the same impedance. I assume the same impedance since in the example the 10" is 8 ohms and the impedance total of the 2x12 is 4 ohms.

    In this case all drivers get the SAME amount of power regardless of size.

    Of course the 12's (efficiency being more or less the same) will be louder than the ten since they have a larger radiating surface (moves more air). There probably wouldn't be a huge difference, and the 10" should be plenty audible.

    That would certainly add to the overall volume of the system due to the factors you mentioned (power increase, larger radiating area).