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2 - Channels, 2 - Cabs, 1 - Question....

Discussion in 'Amps and Cabs [BG]' started by Quadzilla, Mar 30, 2002.


  1. Quadzilla

    Quadzilla Supporting Member

    Hello everyone,

    I have a couple of questions. I will soon have a 2 channel head (Hartke HA 7000 350 x 2 @ 4 ohms). I currently own 2 - 8 ohm cabs. I wish somehow to get full power out of the amp with this config. If I just hook up each cab to each channel, I will only get 240 watts to each cab (cause each channel will be running at 8 ohms). Forgive my ignorance, but can't I bi-amp the channels as 1 and then daisy chain the cabs to get 4 ohms into the one bi-amped channel? I've never had a 2 channel amp with 2 cabs so I'm a little lacking of knowledge on this. Please let me know and thanks!

    Quad
     
  2. SRSiegel

    SRSiegel Guest

    Sep 17, 2001
    Ann Arbor, Michigan
    biamping is not what you want. biamping means using the two seperate channels.... as seperate channels. hence "bi" amp. i dont know if your head can do it, but what youre looking for is to bridge the two channels togther. then you could daisy chain your cabs to get a 4 ohm load (if the head can handle a 4 ohm load bridged) so there are those two BIG IFS. someone who is better experienced with the head you have would know more than i would. best of luck
     
  3. Quadzilla

    Quadzilla Supporting Member

    Both cabs have 2 speaker jacks (not for stereo, they are an in and an out OR two ins I suppose). I wonder if that matters....
     
  4. Quadzilla

    Quadzilla Supporting Member

    Yes according to the specs the head can be bridged and I also know that it can and will do 4 ohms, I just don't know what and how to physically do this (how to bridge the channels, do I daisy chaion the cabs, etc).

    Thanks,
    Quad
     
  5. On the back of your amp there is a bi-amp switch. When the bi-amp switch is set to “Mono” position, full range audio is output from both the low frequency speaker outputs as well as from the high frequency speaker outputs.
     
  6. Quadzilla

    Quadzilla Supporting Member

    My original question is still unanswered. Can I bi-amp it with 2 - 8 ohm cabs and make the total load 4 ohms?

    When you bi-amp how do you hook the speakers up, one from each channel or do you daisy chain em? Each channel will put out 350 watts @4 ohms, so when bi-amped are they working as one at 700 watts at 4 ohms? I soooo confused.... Again here is my rig

    1 - Hartke HA 7000 head (2-channels 350 watts each @ 4 ohms and says it can be bi-amped)
    1 - 8 ohm 4x10 cab
    1 - 8 ohm 1x15 cab

    Link to head -->Link

    Link to head manual-->Link

    How do I hook this up to get max wattage?

    Thanks again,
    Quad
     
  7. SRSiegel

    SRSiegel Guest

    Sep 17, 2001
    Ann Arbor, Michigan
    sorry man. heres how it works on my R600 (its probably the same for you) push the bridge switch in on the back of the head. then you have essentially two speaker outputs that behave as parallel outputs. so you can either plug one speaker into each output jack, or you can daisy chain em and plus them into one jack. it doesnt matter, as now the head has essentially power amp. and to answer your other question; yes, when you daisy chain two 8 ohm cabinets you get a 4 ohm load. theres a formula to calculate the resultant ohm load if youre wondering how it works:

    1/(resistance1) + 1/(resistance2) +....= 1/resistance(resultant)

    the dots mean that if you have more than two cabs, you can just keep adding 1/R terms. the end. (1/8 + 1/8 = 1/4) thas how it works.
     
  8. In a word...no.
     
  9. geshel

    geshel

    Oct 2, 2001
    Seattle
    I don't see anything in the HA7000 manual about bridging. It lists two modes of operation: bi-amp and mono. In each case, you have two output sections that are distinct, each providing 240w/8 ohms or 350w/4 ohms.

    Here's the manual:

    http://www.samsontech.com/products/relatedDocs/ACF1903.pdf

    If you run it in "mono", with one speaker per side, you get 240w x 2 for 480w. If you use only one half of the amp, but daisy-chain the speakers, you'll get 350w x 1, so why bother.

    If you run it in "biamp" mode, you're sending the low frequencies to one speaker and the high frequencies to the other. In this case you've still got 240w x 2, but depending on your speakers this might not make sense (if you've got two 2x10s then why bother to bi-amp).

    So, unless I'm mistaken, the best you can do is run in "mono" mode, with one speaker per side. 480w. Not the full 700w, but then again, the difference between 480w and 700w (especially considering it'd be the same power supply inside the amp backing it up) is trivial.
     
  10. Quadzilla

    Quadzilla Supporting Member

    Thanks Geshel and all who helped on this one!

    Quad