Psst... Ready to join TalkBass and start posting, make new friends, sell your gear, and more?  Register your free account in 30 seconds.

Tweeter Impedance and Resistors????

Discussion in 'Amps and Cabs [BG]' started by rawlsjk, Jan 7, 2004.


  1. Hey everyone. I have a few concerns. I've been doing some searching online for info. on piezo tweeters. I recently bought a few (for my SWR bass cabinet). I totally rewired the cabinet and I'm wondering do the piezo's have their own impedance? I see where it acts like a capacitor (in which the impedance changes with frequency), but other places I see that it says...Impedance: 4 ohms. I don't know if it means that directly or that it works with 4 ohm systems. Another quick question, I wired my 4 - 4 ohm speakers to get a load of 4 ohms, but I want get a slightly higher value. I was going to just add a resistor in series to get a higher ohm reading? Is this the most effecient thing to do? If anyone can help me out, I'd really appreciate it. God Bless!

    Jason
     
  2. The impedance of a piezo tweeter is somewhere around 1,000 Ohms. This is of no concern for the rest in the cab. Just connect it parallel to the woofers and you're fine. You could add a series capacitor to lower the level (info about this can be found on the www), but this is personal taste.

    Adding a resistor to increase the woofers' impedance is a very bad idea if you ask me. It would just be eating up your power. A 1 ohm resistor in series would:

    A. Take 20% of your amp's power
    B. Lower your amp's maximum power output, as it "sees" a higher impedance.
    C. reduce the "grip" your amp has on the speakers (damping factor) and work negative miracles on your bass response. It will sound boomy and muddy.

    And why would you want a higher impedance anyway? If your amp is rated for 4 ohms, connect a 4 ohms cab. Perhaps you're referring to a impedance value you measured yourself. Note that measuring a cab's impedance with an ohmmeter always reads a lower value, because you're measuring at DC, and nominal impedance is specified at AC (1 kHz).