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Adding a tweeter!?

Discussion in 'Amps and Cabs [BG]' started by Groovin_Joe, Feb 8, 2004.


  1. Hello all.
    I don't know if this is the right category so if it needs to be moved, then please do so.

    I have an older Yorkville 400B combo. The one with the 400B head and a 15" speaker. I have been recently been finding my sound at gigs that I have been playing, that I just don't have enough top end. So I talked to my Sound teacher(in college for Recording Arts) and he said that I could install a piezo tweeter, I wouldn't necessarily need a crossover because it could have the capacitor on it. Now assuming I can find one here in the little town I am in, how would I wire that? Would I take out the speaker and wire the new tweeter in parallel with the main 15?

    Any information on this would be great.

    Thanks in advance.
     
  2. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    Chicago
    While piezo tweeters don't "technically" require a crossover, my ears tell me that you'll want one anyway. It's hard to describe but, to me, it cuts down on the harshness.

    If you can't find one locally...gosh, even Radio Shack carries them, you could certainly find one at http://www.partsexpress.com.
     
  3. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    Chicago
    I just reread your post. Piezo tweeters don't have a capacitor on them...the nature of the beast is that they behave like a capacitor; as frequency drops, their impedance increases accordingly.
     
  4. Thanks for all this information. would I want to put an 8 ohm tweeter in parrallel to make the whole cab a total of 4ohm. With a total of 4ohm load would increase the power going to the cab and I may blow my speaker and tweeter with 400 to a total of 725W going to it. or would i want to put a 4ohm tweeter?

    thanks.
    adam
     
  5. patrickj

    patrickj

    Aug 13, 2001
    Baltimore, MD

    You'll still have an 8ohm cabinet. The frequency at which the tweeter starts influencing is roughly the frequency at which the woofer starts falling off, so there's not a significant impedance change. Impedance is more like a 2D graph than a single value, but it's easiest to represent as a single value.

    Basically, you're existing 8ohm cabinet + a piezo tweeter will look nearly the same to your amp as it did before a tweeter, it can just 'play higher' now.
     
  6. patrickj

    patrickj

    Aug 13, 2001
    Baltimore, MD
    Oh, and no, don't get the 4ohm piezo, stay w/ the 8ohm.
     
  7. Thanks a bunch.

    Would an attenuator be a good idea? as to be able to turn it off or perhaps wire it through a switch.

    adam
     
  8. patrickj

    patrickj

    Aug 13, 2001
    Baltimore, MD
    I've never used a piezo so I don't know how well an lpad/on/off would work.. I don't see why they wouldn't work, but at the same time, they don't operate like traditional lpad/resistance + crossover'd tweeters.

    Anyone? :help:
     
  9. The piezo I bought at radio shack has a cap attached to it. I had previously done this to a 15" cab I had and played a few gigs with it, but by the time I sold it, it had quit working. That one did not have a capacitor - and even though I was told I didn't need it, the fact that it blew up makes me think that you should have one. AAMOF, Radio Schack recommends it.

    BT
     
  10. I have been looking for tweeters. and I have found this one:

    I don't know how to show a pic but... Will this work? Just wire in parallel with the main speaker. it is 6K-16KHz and 12 watts RMS and 30watts Max. Does anyone know what kind of capacator will have a crossover point that is lower than 6KHz? perhaps like 4KHz.

    Adam
     
  11. Looks like it has a cap onit already. IIRC the Rad shack piezo I have has a 10 uf on it. Seems kinda big for the 4khz xover they say it is. But the impedance of piezos is not constant I think.

    BT
     
  12. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    It's only 12 watts RMS. I'd bee looking for somehting with a better wattage rating. Low frequencies can blow treewers but so can excessive power.
     
  13. rok51

    rok51

    Sep 2, 2002
    Crawfordville, FL
    Having successfully added piezos to several cabs, I'd like to offer a few suggestions.

    Get a LeSon TLX-1 piezo. It's the same as used by SWR and others. It is a VAST improvement over the CTS/Motorola (and clones) piezos. Normally, I do not like piezos due to their harshness. The LeSon is unbelievably smooth for a piezo. They are also cheap-if you source them correctly. I suggest Martin Sound. They are about $5 a pop. I used a wirewound resistor and a high pass capacitor, per LeSon's recommendations (included in the box). With the protection of the resistor/cap, they are rated at 150 watts rms(I think) Bad day at work. Too much wine :D