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Running 2 Speaker cabs ?????

Discussion in 'Amps and Cabs [BG]' started by MrShawn2U, May 10, 2006.


  1. MrShawn2U

    MrShawn2U

    Mar 20, 2006
    NH
    I have a question since I am new to running head and cab set ups. Is it ok to run a 8ohm 2x10 with a 4ohm 1x15 off of a GK 1001RB-II?? I would think logically that that would equate to somewhere around 6 ohms? Using the logic that running 2 8ohm cabs would equate to 4ohms. I just want to make sure I wont cause any damage to the speakers or the head. Thanks.
     
  2. jpark

    jpark

    Feb 2, 2006
    WV
    With an 8ohm and 4ohm that would run a little over 2 ohms. I'm pretty sure your amp isn't capable of running at 2 ohms. And you're correct, two 8 ohm cabs run at 4 ohms.
     
  3. I think if you ran them in series they should be @ 12 ohms. In parallel they should be @ 3 ohms. It will not damage anything if your head is stable to the ohm load it is driving. I am not sure how stable the 1001RB-II would be @ 3 ohms.
     
  4. jpark

    jpark

    Feb 2, 2006
    WV
  5. MrShawn2U

    MrShawn2U

    Mar 20, 2006
    NH
    Yes, the 1001RB II is rated for a minimum of 4 ohms, so I guess I can't run them normally. So basically if I want to run them in series I would go out of the amp to the 4ohm cab, and out of the 4ohm cab to the 8ohm cab correct? That would equate to 12 ohms?
     
  6. No. The way the cabinet inputs/outputs are wired is such that doing what you described still connects them in parallel, with the resulting impedance of 2.67 ohms as before.

    You would need a modified cable to connect the cabinets in series. However, this is not an ideal solution to the problem.
     
  7. MrShawn2U

    MrShawn2U

    Mar 20, 2006
    NH
    So I guess the solution is to get an 8ohm cab for my 1x15??? The one I have now is a loaner since mine is being serviced. The one being serviced is an 8ohm cab. Ok so next question, I did run the configuration last night, if my amp was running ok at the end of the night do you think I lucked out and avoided damage???
     
  8. Is it still working ok? then its fine

    And your looking for an 8ohm 1x15, there are surely a few of them around, i know peavey make one
     
  9. MrShawn2U

    MrShawn2U

    Mar 20, 2006
    NH
    It was working ok at the end of the night, but at one point in the night I thought I smelled something cooking, now I am worried I may have damaged the head, not good. If I smelled something burning would it quit completely if it fried or could something have fried and it still works?
     
  10. Thunder Lizard

    Thunder Lizard

    Dec 7, 2005
    Lethbridge, AB
    Canadian Distributor, Basson Sound Equipment
    UM, probably not, because the jacks themselves would be wired in parallel, unless it says otherwise somewhere on them. you would need to do one of a few different things.....
    A- have a knowledgeable tech person rewire the first cab so it the jack is a series connection... you might want to make it a different jack, otherwise the cabinet would be useless on it's own....
    B- Create a possibly messy "series cable" ...... in series, the signal would go from the + output of the amp to the + terminal on the first cab...then from the - terminal of the first cab to the +terminal of the second cab, and from the - terminal of the second cab to the - output of the amp.... good part is that it can happen anywhere, it doesn't have to be right at the cabs...
    I've made a horridly messy quick diagram, it might be the best way, because you don't mod anything other than a couple of jacks..... Just wire from the output of the amp to the first jack, the second jack, and plug in cabinets! SERIES.GIF
    It will only work with both cabs plugged in, and then it basically treats them as one large circuit. Series might be safer than what you DID try, but you will likely notice a reduction of volume, because the amp is pushing against more resistance. Watch carefully! Most amps are OK above 8 ohms up to possibly 16....with an 8 and a 4, you should end up around 12, and that's not horrible... it's a cheap experiment! Just don't run the living heck outta it, it's pushing a heavy load there.
    If it smelled hot, it was likely hot. There might be damage, but if it's working the way it used to, it's probably alright. I'd recommend not trying it THAT way again! lol.
    Best of luck!
     
  11. MrShawn2U

    MrShawn2U

    Mar 20, 2006
    NH
    Thanks Thunder, I hope there is no major damage and it just heated up. When I first smelled it I shut it down for a while, then only played for another 20 minutes after. I definintely will not try it that way again, I will return the loaner/rental cab and get an 8ohm cab instead. Thanks, I really hope I didn't do damage to my new amp!
     
  12. 4Mal

    4Mal Supporting Member

    Jun 2, 2002
    Columbia River Gorge
    Good thinking ... It's a 4 ohm amp. Do not go below that or you will damage the amp. You certainly didn't do it any good as it is.

    I run 2 4 ohm cab's in series with my GK. You need a plastic box and three jacks (a, b & c) and wire them as

    a. sleeve (-) to b. tip (+)
    b. sleeve (-) to c. tip (+)
    c. sleeve (-) to a. tip (+)

    Run a cable from your amp to the box and then from the box to each cabinet. Now you're safely running about 450 watts at 8 ohms.
     
  13. MrShawn2U

    MrShawn2U

    Mar 20, 2006
    NH
    I am sure i didnt do it any good, just hoping it will be ok. Believe me if I had realized it I would have never run it that way, but like I said I am new to head/cab setup, I have always run combo's. I know in the future I will be alot more careful.
     
  14. MrShawn2U

    MrShawn2U

    Mar 20, 2006
    NH
    ok, so another question. I returned the 4 ohm 1x15 and got an 8ohm 4x10 rated at 600W. Now would I be better off running just the 4x10 at 8ohms where my amp will push 460W@8ohms, or running my 2x10 8ohm 150W + the 4x10 8ohm 600W where my amp will push 700W@4 ohms? Will it overpower the 2x10 in this case? Also I tested out the amp on just the 1x15 before I returned it and it sounded good, so I think the amp is ok, phew. I am learning, just dont wanna learn the hard way!
     
  15. tysonlb

    tysonlb

    Mar 9, 2006
    Long Beach, CA
    If you do that, then each cab will get 350W. Be careful if you go that route. Just don't crank it and it should be okay.
     
  16. MrShawn2U

    MrShawn2U

    Mar 20, 2006
    NH
    Yeah thats what I figured, but I am wondering am I better off just putting 460W to the 4x10 and not using the 2x10?
     
  17. permagrin

    permagrin

    May 1, 2003
    San Pedro, CA
    Yes, if this meets your volume need. 350W into a cab rated at 150W is a little much if you push it for volume.
     
  18. MrShawn2U

    MrShawn2U

    Mar 20, 2006
    NH
    Well I will try it both ways, and be very leary of turning up too much with the 2x10 hooked up. I think the 4x10 alone will probably be the way I go, I mean could the 2x10 really make it that much louder anyway, especially considering you would have to be careful how loud you turned it up. I generally like a larger drive to give it that bottom end, but we will see if I am happy with a 4x10.
     

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