Dismiss Notice

Psst... Ready to join TalkBass and start posting, make new friends, sell your gear, and more?  Register your free account in 30 seconds.

Hookin Up Cabs...

Discussion in 'Amps and Cabs [BG]' started by B.Hendrix, Aug 16, 2003.


  1. B.Hendrix

    B.Hendrix

    Mar 24, 2000
    Atlanta, GA
    Been playing through combos for several years and recently picked up a used Hartke 4000 and an Eden 2X10 XLT cab(8 ohm). Gonna add an 8 ohm 1X15 to the mix as well. Whats best way to hookem up? The amp has two regular outputs (Eden cant accept speakon - the ONLY flaw). So should I connect each cab to the amp or go from amp to 2X10 to 1X15? BTW, looking at a Mesa 1X15 to round out the rig!

    Responses appreciated!:cool:
     
  2. If all the cabs are 8 Ohms and the Hartke has 2 outputs on the back each labelled 8 Ohm output, you will probably get the best overall sound hooking each cab separately.

    If you connect the cabs off one of the outputs from the head and subsequently the other cab from the first, you will lower the overall impedence if the panel jacks on the cab are parellel in/out. If your cab jacks are wired in series, then stringing them together will add to the overall impedence.

    My experience with Hartke is that they lose control of the sound when you deviate from teh overall 8 Ohm impedence. They tend to have very high output. At less then 8 Ohms you will bring a lot of power to the cabinet and may not give you the clean sound you want. At more than 8 Ohms overall, you will feel you are not getting the power you want.

    Best bet is wire them from the head directly.

    -Pete
     
  3. B.Hendrix

    B.Hendrix

    Mar 24, 2000
    Atlanta, GA
    Thanks!
    The amp puts out 400 watts at 4 ohms, so by hooking both 8 ohm cabs to the amp - am I now running at 4 ohms? Or does it have to be a parallel hookup? :confused:
     
  4. I would have to look exactly how the Hartke head handles its output to answer that. Generally if each output is labelled 8 Ohms, you are most likely running two 8 Ohms parallel that will lower your overall impedence, but not to 4 Ohms. THe formula is not quite that simple. Your output will then be close to the 400 Watts. Just be aware of the minimum impedence the am can handle (usually 2 Ohms, but sometimes 4). Don't go below that or your amp will run too much power to the speakers.

    With what you described, you should be fine running each cab separately from the head.
     
  5. B.Hendrix

    B.Hendrix

    Mar 24, 2000
    Atlanta, GA
    Cool :cool: Thanks!

    The back of the amp just has the two outputs and over both of them, it says "Speaker Outputs - 4 ohm = 400 watts". So sounds like I'm safe just hookin up two 8 ohm cabs directly to the head.

    So - for curiousity sake - what would happen if I ran the amp to just one cab, then daisy-chained that cab to another? (both 8 ohm cabs)
     
  6. Here is a quote from FAQ's in TalkBass.com. You should check that out because many of your questions will be answered there:

    "Ohms are units used when measuring impedance. Basically, the higher the ohm rating of your cab, the less power you will get from your head. So, you might ask, why would I want a cab with a higher ohm rating? Don't I want 300 watts from my 300 watt amplifier? Yes, you do. But if you want to use more than one speaker, you have to learn about the wonders of ohms. When hooking up more than one cabinet in series (Amp->Cab->Cab), as opposed to parallel (Cab<-Amp->Cab), the impedance of the cabinets is changed. The formula to find the resulting impedance is: 1 / (1 / R1 + 1 / R2 + 1 / R3) This would be the formula used when hooking up three cabs in parallel, with R1 being the impedance of the first cab, R2 being that of the second, etc. Add as many 1/RX as needed. So, let's say, for example, you have a head that is rated 400 watts at 4 ohms. (We'll use nice, round numbers.) If you were to hook up two 8 ohm cabinets, the resulting impedance would be at 4 ohms. 1 / (1/ 8 + 1 / 8)= 4 Be sure to check what your head's minimum ohm rating is. If you run a head that has a minimum of 4 ohms at 2 ohms, for example, you risk seriously damaging your equipment."

    What you need to watch out for is that sometimes daisy-chaining WILL be the same as a parallel connection. If depends how the cabinet is wired. They may have parallel in/out jacks in which case daisy chaining the cabinets is the same as parallel outputs from the cabinet.

    I checked back and saw that you said you are using two 8 Ohm cabs. In parallel that will give you 4 Ohms. In series 16.

    -Pete