Newbie Question: 8 ohm load with two 4 ohm drivers?

Discussion in 'Archived Threads 2001-2004' started by GaryLP, Feb 27, 2003.

  1. GaryLP

    GaryLP Agent

    Joined:
    Feb 19, 2003
    Messages:
    29
    Likes Received:
    0
    Hi guys...I am a total newbie when it comes to home audio...and I'm even worse when it comes to DIY stuff.

    If I wanted to make a very simple 3-way set of loudspeakers, how to I achieve an 8 ohm load if most drivers are 8 ohms?

    I assume that if I use a 8 ohm bass driver and a 8 ohm mid driver and I get a custom x-over built by Madisound, I'll get a 4 ohm load right?

    What if I use 4 ohm drivers? Is it possible to get a 8 ohm load?

    Thanks guys.


    Gary
     
  2. Rick Evans

    Rick Evans Auditioning

    Joined:
    May 20, 2002
    Messages:
    14
    Likes Received:
    0
  3. Jeff Meininger

    Jeff Meininger Second Unit

    Joined:
    Jun 5, 2002
    Messages:
    481
    Likes Received:
    0
    Gary: no, you'll get an 8 ohm load.

    With two 8-ohm drivers playing the SAME FREQUENCY RANGE, you would have a 4-ohm load wiring in parallel, and a 16-ohm load wiring in series.

    However, with an 8 ohm bass driver and an 8 ohm midrange, you still have an 8 ohm load. This is because the crossover attenuates the output by raising the impedance.

    [​IMG]
     
  4. GaryLP

    GaryLP Agent

    Joined:
    Feb 19, 2003
    Messages:
    29
    Likes Received:
    0
    Jeff,

    Thanks...that's exactly what I wanted to hear.

    Where's a good place to get a custom passive x-over built? Have you ever used Madisound or Solen? Do you have any idea how much a 12dB 3-way would cost?
     
  5. Jeff Meininger

    Jeff Meininger Second Unit

    Joined:
    Jun 5, 2002
    Messages:
    481
    Likes Received:
    0
    I don't really know anything about "3rd party" crossover design services. I just bit the bullet and paid for LspCAD and built an inexpensive microphone to do my own testing and crossover. I guess it takes a certain commitment to climing the learning curve, too.

    Do these crossover design services test the response of your drivers in the same box on the same baffle that you will use? If not, I'd be skeptical. I'm just a newbie working on his first project, but the overwhelming amount of advice from the folks who know what they're talking about is that a custom crossover built on measured data is key.
     
  6. GaryLP

    GaryLP Agent

    Joined:
    Feb 19, 2003
    Messages:
    29
    Likes Received:
    0
    Yikes...i didn't know it was so complicated. I think I might be in over my head. I just want to build a simple 3-way for my garage.

    Looks like I'm going to have to do a lot of learning.
     
  7. what type of budget are you looking at?

    is this for music to be played loudly?...for thumping bass or for when you are doodling aroundin the garage, or what?

    There may already be a DIY design for your needs. ...would just need to solder up the XO and build the enclosure.
     
  8. GaryLP

    GaryLP Agent

    Joined:
    Feb 19, 2003
    Messages:
    29
    Likes Received:
    0
    Anthony,

    I was thinking about using the JM LABS TMCTIBJM tweeters,
    [​IMG]

    the JM LABS 7C114 S7 midbasses,
    [​IMG]

    and FOCAL 10KN617 10" bass units.
    [​IMG]

    I was thinking about using these because they're pretty cheap.
     

Share This Page