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X-over Question

Discussion in 'Amps and Cabs [BG]' started by Chris_AtariDoll, Sep 30, 2003.


  1. Chris_AtariDoll

    Chris_AtariDoll

    Dec 8, 2001
    UK
    I'm planning on fitting a simple passive HP x-over to my 2x10, to cut some of the lows from it.

    Just wondering if any one knows what value of capacitor is best, and what type to use.

    looking at a x-over point of about 100hz (im using a 1x15 for the lows)
    both cabs are 8ohm

    Thanks
     
  2. Do you have a built in x-over in your amp head? What are you using for power?

    ;) Treena
     
  3. Chris_AtariDoll

    Chris_AtariDoll

    Dec 8, 2001
    UK
    I use a Warwick Pro Fet IV thru a Warwick 2x10 and 1x15. I use a lot of synth type effects and i would like to reduce the amount of sub frequencies going to the 10s.

    The head does not include and x-over options.

    I am looking at changing my head in the future (to a Pro Tube IX, wich includes a x-over), but until then i just want a 'cheap' fix.
     
  4. alexclaber

    alexclaber Commercial User

    Jun 19, 2001
    Brighton, UK
    Director - Barefaced Ltd
    Check out this website:

    http://www.the12volt.com/caraudio/cross.asp

    And this page suggest you want a 200uF capacitor for -3dB @ 100Hz. If I were you I'd set it a bit lower, at about 80Hz which requires a 250uF capacitor.

    http://www.the12volt.com/caraudio/crosscalc.asp

    I think this capacitor from Maplin ( http://www.maplin.co.uk/ ) should do the job:

    JA71N NP 220uF 100V

    Thanks for bringing this topic up - I didn't know that much about crossover design but you got me curious so i've ended up investigating it quite thoroughly.

    There's a jam night I do in London where I'm the house bassist and I have to run through a 50W guitar amp, which sounds amazing considering (it's a 70s 2x12" all-valve Burman, like a heavier and much bassier Fender Twin). However I've been quite worried about blowing the speakers so I might wire a capacitor in to protect the speakers from extreme lows.

    Alex
     
  5. BruceWane

    BruceWane

    Oct 31, 2002
    Houston, TX
    That 100 volt rating means it's good up to about 200 watts.........you might want to get a higher capacity. It gets harder to find capacitors as you get into higher microfarads, so remember that you can combine them by wiring them up in parallel to get to the value you need, i.e. for a 220uF value you could use 2 100uF caps plus 1 20uF cap. Make sure they are intended for audio crossover use.