Cab: 4ohm or 8ohm?

Discussion in 'Amps and Cabs [BG]' started by BloodTypeBlue, Mar 5, 2006.

  1. BloodTypeBlue


    Feb 15, 2006
    I've recently begun to put together a new bass rig. Just today I won a Trace Elliot AH300 on eBay (300W @ 4ohms), and now I'm looking for a cab to go with it. I'm almost certainly going to order an Avatar B410NEO, but I don't know what impedance to get it in.

    I am a college student with very limited resources for storing or transporting such bulky pieces of equipment, so this will probably be my only cab in the foreseeable future. However, I'm still wondering whether to get the cab in 8ohms, so that maybe one day I can decide to add another cab.

    The Avatar website says that using an 8ohm cabinet instead of a 4ohm cabinet will cost me only 3db in volume. However, this doesn't make sense to me from a basic P=V^2/R perspective; wouldn't twice the impedance, at the same voltage, lead to half the power? :confused:

    The band I play in is very loud; I'm currently borrowing a friend's Ashdown MAG300 (300W) into 4ohms, and both input and output levels are always about halfway up. I'm afraid that if I use an 8ohm cab with the Trace Elliot, I will have to keep it cranked at all times, which I'm not too comfortable with.

    Can anyone help me out? :help:
  2. BloodTypeBlue


    Feb 15, 2006
    Ack, never mind. Just read the FAQ and learned that a 3db volume drop and a 50% wattage drop are indeed one and the same...

    So, new question: suppose I am going from a 4ohm, 8x10 setup to an 8ohm, 4x10 setup. Will this drop my volume enough to cause me to get drowned out?
  3. Lowtonejoe

    Lowtonejoe Supporting Member

    Jul 3, 2004
    Richland, WA
    If you are on the edgs now this might indeed send you sailing over.

    If I'm reading you right you will lose 6db.

    Not good.


  4. Mystic Michael

    Mystic Michael Hip No Ties

    Apr 1, 2004
    New York, NY

    A Trace Elliot is a nice make, but 300 watts just ain't a whole lot of headroom - especially for a band that's "very loud". Normally, there are more, better reasons to invest in an 8-ohm cab than in a 4-ohm cab, mostly for the flexibility to add an additional 8-ohm cab later and still stay within your amp's range of safe operating loads.

    But this assumes that you'll have enough power to adequately power both cabs. In your case, you won't - unless you also invest in a second amp to drive the additional cab, or trade in the Trace for a much more powerful amp to drive everything.

    For the present time, the 4-ohm cab is the only way to go. Avatars are reputed to be very efficient, so you might be just fine with the Neo 410...