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bi-amp/crossover

Discussion in 'Effects [BG]' started by MarkMcCombs, Sep 24, 2001.


  1. Does anyone know if there's any sort of stomp box that divides the signal into hi and lo frequencies? Or another cheap way of doing it before amping?

    Thanks,

    Mark
     
  2. JMX

    JMX Vorsprung durch Technik

    Sep 4, 2000
    Cologne, Germany
    One way to do it:

    Get a line spitter and two EQ pedals

    Put on EQ in each of the two outputs and roll off the highs on one and roll off the treble on the other.
    That way one signal path has the lower frequencies and the other the higher ones.

    But this is obviously not the optimal way to do it.

    There are crossover units available for P.A. use, you could try one of those.
     
  3. There are tons of schematics on the web, but a crossover is really just a capacitor and resistor. Much easier and cheaper to make/buy than using two EQs.

    For not too much you can swing over to Radio Shack and get one already made. You'll have to solder it into a speaker cable or whatever you plan to use to hook it up. They'll have wiring diagrams and are usually helpful. Might even want to pick up the cables and plugs you need while you're there.

    OK, I looked this up on the net: looks like you're gonna be out $13 plus cables and plugs, depending on your setup and what you've got lying around the garage.

    RadioShack Two-way Crossover Network

    *edit: Link seems not to work for me: Go to Radioshack.com and type in part number 40-1296. That's your jammy!

    Good luck. Shouldn't be too hard.
     
  4. Thanks, Surfslave. But I think that's a passive crossover, that is used after the amplified signal and before the driver(s). What I want to do is an active crossover, and then bi-amp the 2 signals themselves. I know there are rack system active crossovers, but I don't want to have to do that, cause I don't have a rack system.

    From what I read, putting in a passive crossover will work, though there is the potential of phase problems and a loss of signal because it's going through resistors and capacitors and such. This may be the route I take, however.

    Basically, I want to extend the high frequencies of my B100-R combo amp. I don't know if there's even room to install even the smallest tweeter, or if I want to do that. So I was thinking with an active crossover, I could send lows and mids to the B100-R, and the highs to another smaller combo in which there's a tweeter, maybe only a tweeter.

    Maybe I'm crazy with this. But I love the sound and look of my Ampeg, I just want some highs to go along with it....

    Mark
     
  5. brianrost

    brianrost Gold Supporting Member

    Apr 26, 2000
    Boston, Taxachusetts
    You can buy active crossovers for dirt cheap. I had a used Ashly 3-way crossover that I paid $49 for.

    Put it in the effects loop of your amp. Effect send to crossover in, one output back to your effects return, the other to a second amp.

    There is ONE pedal I know of with a crossover built in. It's no longer made, but at one time Peavey sold a bass chorus pedal with a crossover built in.
     
  6. I think I found an answer in Rolls...the SX21

    http://www.rolls.com/new/frame2.html

    I think I'll set the crossover to about 3K, and run lows to the B100-R, and the highs to something else, maybe the hatchet job I plan to do to my 10-watt combo, replace the speaker w/a Piezo tweeter. We'll see what happens, but I think I'm onto something here.

    Mark
     
  7. Mark,

    Re: Passive crossover. Sorry about that. You're right that the lows/highs will be out of phase. OTOH, soooo many speaker designs use these crossovers...

    I'm a little interested in doing the same, b/c I have a combo with only a 12" speaker. It would be fun to run the high frequencies out into a smaller unit. Though I might do it with a passive crossover. I'll tell you how it goes.

    Now just for fun, I've included a link for a cool crossover design that I think meets all your requirements.
    Linkwitz-Reily Crossover For mono, you'll only need one of the circuits, of course. There are other good crossover designs on his page too, as well as general bi-amping advice. Don't know if this is helpful or if you want to do it entirely yourself...

    Your active crossover plans sound fun. Keep us updated when you get it working.
     
  8. Slave:

    Yes, this is fun to think about. Never considered myself an electronics techie, however. My grand plan is to buy some used crappy 20-watt (will this be enough power?) guitar amp or something, take the speaker out and replace it with a tweeter. I think I'll also cut it down so it's not so tall, maybe to about 8 inches tall or so. In it I'll place the Rolls crossover, and have jacks for input and two for output (hi and lo). I want to cover it in blue check Tolex if I can get some from Ampeg, and use the same grill cloth as my amp, corner pieces, etc. Basically, I want it to look like it's a matched set, vintage, but giving me the option of modern, somewhat hi-fi sound.

    So the chain will be... bass-SansampDI-Rolls Crossover SX21-hi's (above 3Khz) to homemade thingy, lows to Ampeg B100R. I must be nuts.

    I think this plan will be in planning for a while and in production a long time....
     
  9. or, I think I could just use the line-out of the Ampeg, and into a modified guitar amp with the speaker replaced with a piezo tweeter. I understand that a piezo does not require a crossover. Course, then I would still be amplifying the lows in the homemade tweeter amp thing, which would probably screw up the sound of the tweeter amp.