Impedence of Shiva in parallel(4ohms - Help)?

Discussion in 'Archived Threads 2001-2004' started by Scott M, Jun 6, 2001.

  1. Scott M

    Scott M Agent

    Joined:
    Jan 3, 2000
    Messages:
    27
    Likes Received:
    0
    Trophy Points:
    0
    I am currently running my new sonosub(shiva)with 2 monoblocks. Each VC is getting 125W each from 2 Soundstream THX cert monoblocks.
    When I try to run in parallel with just 1 block the first one seems to run fine but the other is going into standby. I'm assuming some type of short protection from low impedence because it jumps into standby in just a few seconds and isn't that hot. This thing is rated to run 4ohms so I'm confused.
    Does the Shiva drop well below 4ohms in parallel? Or is there something wrong with the amp? My LSPCAD model for the sub doesn't show anything below 4.4ohms in parallel until you get below 12hz or so but I'm not sure if this is reliable.
    As an after thought I'm probably going to look into a AVA250 but I'm wondering if I should get the blocks looked at because they are slated to run my new Studio 60s when I get them.
     
  2. Jack Gilvey

    Jack Gilvey Producer

    Joined:
    Mar 13, 1999
    Messages:
    4,948
    Likes Received:
    1
    Trophy Points:
    0
    According to the Shiva white paper, the Re with parallel VC's is 2.82 ohms. Might be a little low for the amp, though I can't say why only one of them would have a problem.
     
  3. Patrick Sun

    Patrick Sun Studio Mogul

    Joined:
    Jun 30, 1999
    Messages:
    38,777
    Likes Received:
    492
    Trophy Points:
    9,110
  4. Julian Data

    Julian Data Second Unit

    Joined:
    Oct 5, 1999
    Messages:
    408
    Likes Received:
    0
    Trophy Points:
    0
    I concur with Pat, something is amiss with that amp.
    ------------------
     
  5. DanWiggins

    DanWiggins Second Unit

    Joined:
    Aug 15, 1999
    Messages:
    324
    Likes Received:
    0
    Trophy Points:
    0
    Scott,
    The LspCAD impedance curve is correct (provided you've entered the design correct, but from the 4.4 ohm minimum you state it sounds right). A typical "4 ohm" driver will dip down to between 3.5 and 4.5 ohms at minimum, depending upon the box/tuning used.
    So I'd go along with the others here and say you need to have that amp checked out. There may be a problem with it.
    Dan Wiggins
    Adire Audio
    ------------------
     

Share This Page