Why would a manufacturer use a 4-ohm driver in a speaker rated 8-ohm nominal? (1 Viewer)

[John Pine]

This question came up during a discussion about upgrading my speaker wire from 16 to 12 gauge. Here's the link if you are interested.
http://www.hometheaterforum.com/htfo...threadid=72076

 

[Walt N]

Two 4-ohm drivers wired in series = an 8-ohm load.

 

[John Pine]

Walt: OK, so if they used two 8 ohm drivers the nominal impedance would be 16?

 

[Fong]

in series, yes

 

[Dustin B]

And two 8 ohm drivers in parallel would be 4ohm nominal.

 

[John Pine]

Got it, thanks!

 

[Mark Fitzsimmons]

Isn't it also possible to use two 4-ohm drivers and still have the final impedance 4 ohms?

 

[John Garcia]

Isn't it also possible to use two 4-ohm drivers and still have the final impedance 4 ohms?

Yes, the design of the crossover can be used to determine the nominal value of a speaker.

 

[Mark Fitzsimmons]

Thats what I thought, thinking back upon component sets for car audio, two four ohm drivers and crossover equates a four ohm final impedence.

 

[John Pine]

That's what I thought, thinking back upon component sets for car audio, two four ohm drivers and crossover equates a four ohm final impedance.

OK.....so I come back to my original question, any acoustical advantage in using 4-ohm drivers instead of 8?

 

[Patrick Sun]

It has more to do with making speakers that are friendly to the amp, as most receivers are designed to provide a certain amount of current, and when a speaker present a low impedance load, the amps in receivers have a harder time providing the necessary current to the speaker, and you run the risk of clipping the amp, which will damage the speakers over the long run. So that's why commercial speaker designers shoot for a nominal 8 ohm impedance rating, but impedance is a function of frequency and there may be some part of the frequency spectrum that dip in the danger zone for low impedance. It all depends on the final circuit that the driver and crossover components create for the amp.

 

[John Pine]

Thanks for the insight Patrick!