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GK 800RB cab/ohms

Discussion in 'Amps and Cabs [BG]' started by woof*, Feb 12, 2006.


  1. woof*

    woof*

    Feb 3, 2006
    hi all
    ive been searching all over trying to get some answers and opinions on this. i cant seem to find a definative- for sure no question about it- answer. i have a GK 800RB on the way and will purchase some cabs. i know most people run this amp full range.
    i also know the top amp is 100w and only 8ohm,while the bottom has two inputs and can use 4ohm. i found this question but no definate answer i could see....some say yes and some say maybe. can i for sure use a 2x10 8ohm on top and a 4x10 4ohm on bottom running full range? i plan to get avatar cabs.(based on price for my budget) thanks in advance for your help!
     
  2. Lowtonejoe

    Lowtonejoe Supporting Member

    Jul 3, 2004
    Richland, WA
    Well,

    I think typically, when someone runs a GK amp 'full range' that means that they are NOT biamping and would only be using the 300w amp. Since the 300w amp has a 4 ohm minimum you would NOT be able to run both cabs safely with the 300w amp.

    You CAN use both cabs if you are biamping, of course. The 8 ohm 2x10 would plug into the highs and the 4 ohm 4x10 would plug into the lows. But from what I remember about the amp for the highs is that it has very little bass response.

    I would definitely get two 8 ohm cabs. I am sure that you will end up running what I previously defined as 'full range'. This would actually give you 3 usable rigs. A 210 for small gigs, 410 for medium gigs and both cabs together for bigger gigs.

    (You may want to consider getting a 210 and a 115 or a 410 and a 115 instead of a 210 and a 410.)

    Two 8 ohm cabs ran together, in parallel, would make a 4 ohm load.

    An 8 ohm cab + 4ohm cab would make a 2.6 ohm load.

    Hopefully I answered your question.

    :D

    Joe.
     
  3. Herman

    Herman

    Dec 25, 2005
    Lynchburg, VA
    Yes, you could. In full range mode, the same signal (bypassing the internal crossover) is sent to both the high and low outputs after going through separate 100W and 300W amplifiers. You could also run 2 8 ohm cabs in parallel on the low output and 1 8 ohm cab on the high (in full range mode) to get all the available power from your amp.

    You could also do this in bi-amp mode but you'd be sending just the higher fequencies (as determined by the internal crossover) to your single 8 ohm cab on the high output.
     
  4. Lowtonejoe

    Lowtonejoe Supporting Member

    Jul 3, 2004
    Richland, WA
    After looking at the block diagram from the manual, you are right.

    [​IMG]

    But adding a 100w 210's volume to a 300w 410's wont do a whole lot for your total volume.

    :D

    Joe.
     
  5. Herman

    Herman

    Dec 25, 2005
    Lynchburg, VA
    I think that depends on at least a couple of things - i.e. placement of the cabs and their relative sensitivity ratings.
     
  6. woof*

    woof*

    Feb 3, 2006
    hey thanks for the help!
     
  7. Lowtonejoe

    Lowtonejoe Supporting Member

    Jul 3, 2004
    Richland, WA
    I suppose that is true.

    But generally it doesn't seem to be very practical to do. If one cab is just stacked on the other, and have the same sensitivity rating (individual speakers) the four 4 ohm cab speakers will drown out the two 8 ohm cab speakers since the 4 ohm cab will have twice as many speakers and will be getting three times the power.

    But hey, different strokes.

    :D

    Joe.
     
  8. Herman

    Herman

    Dec 25, 2005
    Lynchburg, VA
    I was thinking more like having the cabs on opposite sides of a stage and the 8 ohm being about 4-5dB more sensitive than the 4 ohm - then you might hear a difference. Just hate the idea of leaving 100W unused.:D
     
  9. Lowtonejoe

    Lowtonejoe Supporting Member

    Jul 3, 2004
    Richland, WA
    Heh heh.

    I see what you mean.

    I know what you mean.

    :D

    Joe.
     
  10. birminghambass

    birminghambass Supporting Member

    Sep 18, 2002
    Birmingham, AL
    Yes, you definitely can. I run it this way and it sounds great. I tried biamping but I prefer the sound of both amps running full range.