Need help understanding crossovers! (1 Viewer)

[BryanDO]

Hey guys, I noticed something today with my 3 way home speakers. All three of the drivers are 8 ohm, yet the final impedance is 8 ohm. How are they wired or crossed over to cause this? I thought three 8 ohm loads would yield a 2.66 ohm load? I'm going to be building my own speakers and I'm trying to understand how to wire and cross them over. I will be building 4 large bookshelfs for highs and mids, my subs can handle 80 and below. I want my speakers to handle everything else. thanks guys...

 

[BryanDO]

Can any DIY'ers give me a hand with this? I'm getting anxious to start my speakers, thanks...

 

[Dustin B]

http://www.speakerbuilder.net/web_fi.../phat/hpif.htm

My advice is unless you plan on making speaker building a serious hobby, stick with kits where the driver choice and crossover design have been done for you.

 

[Brian Fellmeth]

This would only be true if the 3 drivers were wired in parallel with no crossover components in series with the signal. Actually, it wouldn't even be true then. An "8 ohm" driver does not behave like an 8 ohm resister. Its resistance is variable depending on frequency. The "8 ohm" rating is kind of a summary- at some frequencies its higher and at some its lower. In addition, the caps and inductors in the crossover are present frequency dependent resistence to the signal. Caps are more resistive at low frequencies and act like shorting wires at high frequencies, and inductors are the reverse.

Dustin's advice is correct. Follow a recipe.