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Ohms And Bass Horns?

Discussion in 'Amps and Cabs [BG]' started by Dumfish, Jan 11, 2003.


  1. Dumfish

    Dumfish

    Oct 6, 2001
    Santa Rosa, Ca
    A couple days ago I was given 2 bass horns. The horns run at 8 or 16 ohms. The combo amp I have only runs at 4 ohms. Can I still use the horns with this amp without something blowing up, or shorting, or breaking, or something of the sort?

    Getting a new amp is not an option for me right now, so any other suggestions would be fine.
     
  2. Dumfish

    Dumfish

    Oct 6, 2001
    Santa Rosa, Ca
    It's a Dean Markley K-100B, 150 watts, 4 ohm speaker. It has two inputs, line in, and line out jacks. I really don't know a whole lot about amps so I'm sorry in advance if the information I'm providing isn't enough. If you need more just let me know and I'll try to find it.
     
  3. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    Sounds to me like your combo has a 4 ohm amp pushing a 4 ohm speaker. Most combos do. And the absense of a socket for "extra speaker" confirms it for me.

    You say these horns have and impedance of 8 or 16 ohms. If you ad a speaker or horn which has a nominal impedance, it will create too much resistance and damage your amp.

    You can get horns that do not alter the nominal impedance. And they're not expensive.
     
  4. Dumfish

    Dumfish

    Oct 6, 2001
    Santa Rosa, Ca
    I remember seeing somewhere that if they were wired parallel the impedance would be 4 or 8 ohms. And if they were wired in series that the impedance would be 16 or 32 ohms. Wouldn't I be able to wire the 2 horns parallel and be suitable for the amp, or am I missing something?

    Edit: Irrelevant
     
  5. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    yep that's right. If you use series wiring, simply add together the impedance of each speker and that's what your entire cab is now rated at. So if your existing speaker is 4 ohms, and the horns are say 8 each, the speaker will have a total impedance of 20 ohms (4+8+8=20). The result will be a loss of power from the amp.

    Ideally you want a total load of 4 ohms so tha amp can run at full power. 8 ohms may be ok as well, but I wouldn't wanna go any higher. Whatever you do don't go below 4.

    You may have to use a combination of series and paralell.

    If the horns are 8 ohms each, wire the horns in parallel to get them to 4 ohms, than add the speaker in series to make a total 8 ohm load.

    If the horns are 16 ohms each, it's harder. the above combination results in 12 ohms and that's no good.
     
  6. Dumfish

    Dumfish

    Oct 6, 2001
    Santa Rosa, Ca
    Thanks for the help. I got the horns hooked up and I tried them out. The sound I got was a very low volume and a little scratchy. Could this be a wiring error on my part or something else? Has anyone else ever dealt with this?