Impedance curver graph

[Bruce Weiland]

Hi Guys and Gals,

I know our stats' impedance drops quite low in the upper frequencies. I believe my Prodigy are spec'd at 2 ohms at 20kHz.

I have been unable to find any graph of the impedance curve of my or any ML speakers.

I don't suppose anyone has that information, do they?

Next, the Prodigy are "nominal" 4 ohms. I assume that it running them full range.

I don't suppose anyone knows what the nominal impedance is for each sections, woofers, panels, when bi-amped, do they?

Thanks for any input.:bowdown:

Bruce

 

[rhd1953]

ML CLS IIa Plots

I got these from Jim Powers (at ML) a long time ago.
These are for the CLS IIa's only!

 

[nsgarch]

It just blows my mind how phase-coherent the panels are!!

 

[Bruce Weiland]

Thank you for the graph.

I don't suppose you have any idea, how close a Prodigy panel would mirror these curves over the bandwidth that the panel covers, do you?

Again, thanks for you time.

Anyone else have any graphs?

Bruce

 

[JonFo]

Hi Bruce,

I happen to have the impedance graphs of the Monolith III's from an Audio article from Sept. 1991. It showed both the passive crossover impedance and the direct drive impedance.

Here are the ones using the passive crossovers, which will be most like what your Prodigies have. But I do note that it's only in the ballpark, they have changed their crossover designs often over the years.

The interesting one to note is the complex impedance curve, where it clearly shows that ESL's are largely capacitive from the mid-range on up.

Not all amps are designed to cope with the large back-EMF of a capacitive load, which is why amp selection is critical for ESL's.

 

[crusty]

Hi Bruce,

You might want to try this link:

http://stereophile.com/floorloudspeakers/390/index5.html

They also have measurements for other Martin Logan speakers.

crusty

 

[Bruce Weiland]

Thanks to all. This is very helpful.

I find it interesting the CLS's which are supposed to be difficult to drive and the graph looks so "smooth" compared to the Monoliths.

Additionally, the graphs at Stereophile were wonderful for two reason, 1) it was the information I was looking for 2) and was specific to my speakers.

The only thing I don't know, and I doubt anyone other than ML ever did the work, is what the woofer section and the stats look like driven individualy. However, I believe I can interpolatively guess from the graphs.

Thanks again to all. JUST WHAT I WAS LOOKING FOR.

Bruce

 

[rhd1953]

Just ask ML

Just ask ML. That's how I got those plots of the CLS II's. They might email them to you, on the spot.

 

[Bruce Weiland]

I did not try that because of my previous experience of trying to get information on my Depth's.

While they were pleasant, and I was contacted by more than one individual they were less than forthcoming on any of the information I asked about.

I expected a similar experience if I asked for graphs of the Prodigy.

However, I will ask.