Electrical Impedance and Choosing Amplifier

[simonsig]

Dear diyaudio forum,

I have a hornresp design showing the following curve for Electrical Impedance (see attachement).

What ohm value should I choose for the amplifier?

What kind of issues could emerge with those two peaks (going over 150 ohms)?


Kind regards,
Simon

 

[MarcelvdG]

If the horn loudspeaker is designed to be driven with voltage, like almost all modern loudspeakers are, then any amplifier with near zero output impedance designed for nominally 8 ohm loads (*) should work well and the impedance peaks will cause no problems unless you use excessively long and thin loudspeaker cables.

(*): That is, just about any amplifier except valve amplifiers without feedback and some exotic types.

 

[simonsig]

Thank you for your response!

So should the amplifier be over or under 8 ohms? Hopefully that question makes sense.


Kind regards,
Simon

 

[Galu]

Although there are high impedance peaks, the amplifier only needs to be rated into 8 ohms as per the previous post - it doesn't have to be rated above 8 ohm.

For most of the frequency range the impedance is in the order of 8 ohm and that's all you need to worry about.

 

[JMFahey]

Don´t want to guess looking at your graphs, what is the actual MINIMUM impedance they show?
Because there is where the actual problem lies.

If never below, say, 6 ohm; reaching 5 ohm tops, an 8 ohm rated amp is fine.

High impedance areas, no big deal.