[trefork]

Warning: Ignoramus question:


My Mordaunt-Short speakers are rated as 4-8 ohms. What does that mean? I thinking of buying the Onkyo SR606 receiver, which can only handle 8 ohm speakers. Should I?

 

[Chu Gai]

That's hard to say without a lot more information. As to what the 4-8 ohms means, I frankly don't know what MS interprets that to be. For example, the impedance plot of their Performance 6 looks like this.

The speaker's impedance (the resistance as a function of frequency) varies from a low of about 3.5 to a high of about 10 ohms. Now, if you're going to use a sub, set the speaker's to small with a crossover of about 80 hz, sit maybe no more than 3 meters away, and not routinely listen above reference levels, a receiver that's only spec'd to 8 ohms just might cut it. The thing is, your listening preferences are unknown as is your room and for that matter the receiver you plan to use. Power ratings on receivers tend to be a bit optimistic and I don't know what the SR606 is capable of doing especially at 4 ohms. What are you using at the present time for a receiver?

 

[trefork]

I'm currently using a circa 2001 Denon (model number escapes me).

 

[Chu Gai]

When the police retrieve it or it winds up on America's Most Wanted, write it down.

 

[trefork]

Is my current receiver really relevant? If so, I'll post it when I get home.

Regardless, the graph you posted is helpful. So resistance of "4-8 ohms" really means just that; variable resistance depending on frequency of signal. Interesting.

 

[Chu Gai]

Yes, it's relevant because it might allow for any measurements that were performed on the receiver to be compared to the one you're considering. I take 'variable resistance' to mean nothing more than impedance, which always varies with frequency.

 

[trefork]

But judging from the graph, doesn't that mean that my speakers are really just 4 ohm speakers? Or that they should be classified as such?

 

[vinipux77]

I would agree, that looks like "4-ohm" graph to me.

 

[Chu Gai]

I don't know if your model of MS is the one I mentioned or some other which may have an entirely different impedance curve.

 

[trefork]

I use the MS304 and MS302.