Question about speaker impedance

[jhinkel]

Hello,
First, let me talk a little bit about my setup to give some background. I have a pair of Cerwin vega model 23 speakers from the 1970s, and I have them hooked up to my Pioneer Sa7100 integrated amplifier.

Now, my impedance question is this:

My Cerwin Vegas say "4 - 8 ohms" on the crossover, and my amplifier
says that in order to add a second pair of speakers to it, both pairs of
speakers have to have an impedance of 8 ohms or more. What does
the "4 - 8 ohms" designation mean in terms of this setup? Would my
Cerwin Vegas have the correct impedance to make this setup work
without any damage to my amp?

Any help would be greatly appreciated . Thank you very much!

 

[hifi_nut]

Would my
Cerwin Vegas have the correct impedance to make this setup work
without any damage to my amp?

Yes, just as long as you don´t connect another set of speakers in series with your CVs.

 

[Zilch]

My Cerwin Vegas say "4 - 8 ohms" on the crossover, and my amplifier says that in order to add a second pair of speakers to it, both pairs of speakers have to have an impedance of 8 ohms or more. What does the "4 - 8 ohms" designation mean in terms of this setup? Would my Cerwin Vegas have the correct impedance to make this setup work without any damage to my amp?

It means until you determine the actual impedance of your CVs, you can't connect two pairs in parallel without risking damage to your amp.

Yes, just as long as you don´t connect another set of speakers in series with your CVs.

Meaning parallel, not series, presumably....

 

[hifi_nut]

Meaning parallel, not series, presumably....

Doh, of course.:tongue: Thanks Zilch.

 

[Chazb11]

4-8 ohms tells you nothing.

If you measure DC resistance across the speaker terminals (disconnected from amp of course) a 4 ohm nominal speaker will usually measure between 3 and 4 ohms, an 8 ohm nominal speaker will measure between 7 and 8 ohms....generally speaking.

 

[greenboy]

If you measure DC resistance across the speaker terminals (disconnected from amp of course) a 4 ohm nominal speaker will usually measure between 3 and 4 ohms, an 8 ohm nominal speaker will measure between 7 and 8 ohms....generally speaking.

Quite a few pro sound woofers, maybe the majority, read between the low 5's and low 6's for drivers that are nominally 8 ohm loads; I'd assume this is sometimes the case with home-oriented woofers.

 

[Zilch]

Are we talkin' DCR of systems or individual drivers?

Depending on the crossover, DCR will read the woofer plus whatever inductor's in series with it, assuming there's a highpass on whatever midrange is in there.

None of this is reliable; you've got to do an impedance sweep, of have the factory spec in hand.... :yes:

 

[Face]

I agree with Zilch. There are speakers rated at "8 ohms", but can swing down to 3ohms at times. Measuring the resistance between the binding posts won't tell you that.

 

[jhinkel]

you've got to do an impedance sweep, of have the factory spec in hand.... :yes:

I am not a hard-core do-it-your-selfer, so would you be able to tell me how to do an impedance sweep, Zilch? Also, thanks to everyone for giving their input.

 

[Zilch]

I am not a hard-core do-it-your-selfer, so would you be able to tell me how to do an impedance sweep, Zilch? Also, thanks to everyone for giving their input.

Fig 1.1 here:

http://sound.westhost.com/lr-passive.htm

OR, purchase Woofer Tester and learn how to use it.... :yes: