4ohm woofer and 8ohm tweeter.

I'm making two pairs of nice little speakers, one for my rear speakers and one for the main speakers for the parents of a friend of mine. I've decided on the parts to use, but the woofer is 4ohm and the tweeter is 8ohm (2-way system), now I've always stuck with using the same impedence drivers so I know not what to do. Is it alright to leave them as they are (I doubt it)? Or should I connect some sort of impedence correction circuit? If so could anyone point me towards documentation regarding such things? Thanks again...
 
I think it may be a bit more complicated than matching the nominal impedences. You must also take into consideration their relative efficiencies.

Zobel networks are usually used to flatten speaker impedences across the useful frequency spectrum so that passive crossovers can do their job better, at the cost of an overall lower impedence.

Perhaps you should consider bi-amping. :)

-Won
 
There's no law that says that your drivers must be of the same impedance, however, bear in mind that the impedance curve for the finished speaker will reflect the fact. You'll have something approximating 4 ohms up to the crossover point, then 8 from there on up. Whether that suits you (and the amplifier) is another question.

Grey
 
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GRollins said:
...You'll have something approximating 4 ohms up to the crossover point, then 8 from there on up. Whether that suits you (and the amplifier) is another question.

agreed, the question is will your (and your friend's parents) amps be happy with a 4 ohm load?

If yours is in a home theater setup... just check the manual. If you plan on running A + B sets of speakers... many receivers require the four speakers to be 8 ohm min. (across the board)
 
Oh, my amp is perfectly happy with a 4ohm load, and eventually I'll add a center channel for dolby surround and all. As for my friends amp, if the speaker is 4ohm, they'll buy an amp that'll run it. Kinda introducing my friend into speaker building by him using his parents funds... Thanks for the info though...