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Help!Impedance vs. frequency for CLSIIs

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raanan

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Does anyone know where I can find a graph of the abovementioned?
I am thinking of ordering a SE 6336A amp,and the builder needs to know the graph for the OPTs that he will wind.Thanks,Raanan
 
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dyazdani

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Does he need to know the curve, or simply the min/max impedance?
 

Spike

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Here's an outdated one for CLS II from the StereoPhile site. I did not have any luck finding one for the CLI IIz you mentioned. You should google for "stereophile martin logan cls" and see some updates to the CLS article but no recent impedance curve.

S'Phile measurement of CLS II

Spike
 

raanan

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dyazdani said:
Does he need to know the curve, or simply the min/max impedance?

Thanks for your response.He needs to know what the impedance is at various frequencies-which would mean-the curve.But if that is classified info-min. and max. would also be helpful.Raanan
 

raanan

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Spike said:
Here's an outdated one for CLS II from the StereoPhile site. I did not have any luck finding one for the CLI IIz you mentioned. You should google for "stereophile martin logan cls" and see some updates to the CLS article but no recent impedance curve.

S'Phile measurement of CLS II

Spike
Thanks for your help.That graph in S'phile is,unfortunately,for the original,and not for the CLS II.My searches have not turned up anything re the curve for the II,only that impedance dips down to 0.6 ohms at 20khz.
I need to know the max. impedance,at at which frequency this occurs.A graph would be even better.Thanks,Raanan
 

Peter Hogan

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raanan said:
Thanks for your help.That graph in S'phile is,unfortunately,for the original,and not for the CLS II.My searches have not turned up anything re the curve for the II,only that impedance dips down to 0.6 ohms at 20khz.
I need to know the max. impedance,at at which frequency this occurs.A graph would be even better.Thanks,Raanan
Hi,
If you have (or can get) a signal generator, a voltmeter, and a low value resistor, say around 5-10 ohms, you can do it yourself. Put the resistor in series with the speaker, then feed it a fixed level signal from the generator (through your power amp). Measure the total voltage applied, and the voltage across the resistor. Since you know the value of the resistor, you can calculate the value of the speakers impedance from the ratio of the voltages.

To use some simple numbers, lets say you are applying 2 volts of total signal and are using a 10 ohm resistor. If you measure 1 volt across the resistor, that means you have 1 volt across the speaker. Since the resistor is 10 ohms, the speaker is also 10 ohms impedance, at that frequency. Then step the frequency up and repeat. Once you have all the data points, plot them on a graph. If, at the new frequency, the voltage across the resistor was 1.5 volts, that means the speaker has .5 volts across it. The speaker now has 1/3 the impedance of the resistor, since it has 1/3 as much voltage dropped across it as the resistor does, or 3.3 ohms impedance.

HTH,
Peter
 
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dyazdani

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Yep. I would suggest measuring as well. Another option would be to call ML and see if they can send you something - they're usually quite helpful.
 

raanan

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Peter Hogan said:
Hi,
If you have (or can get) a signal generator, a voltmeter, and a low value resistor, say around 5-10 ohms, you can do it yourself. Put the resistor in series with the speaker, then feed it a fixed level signal from the generator (through your power amp). Measure the total voltage applied, and the voltage across the resistor. Since you know the value of the resistor, you can calculate the value of the speakers impedance from the ratio of the voltages.

To use some simple numbers, lets say you are applying 2 volts of total signal and are using a 10 ohm resistor. If you measure 1 volt across the resistor, that means you have 1 volt across the speaker. Since the resistor is 10 ohms, the speaker is also 10 ohms impedance, at that frequency. Then step the frequency up and repeat. Once you have all the data points, plot them on a graph. If, at the new frequency, the voltage across the resistor was 1.5 volts, that means the speaker has .5 volts across it. The speaker now has 1/3 the impedance of the resistor, since it has 1/3 as much voltage dropped across it as the resistor does, or 3.3 ohms impedance.

HTH,
Peter




Appreciated.Raanan
 
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georgehifi

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This should be very close to yours, it's for the MonolithIII from 150hz up it should be almost identical to the CLS. (Thanks go to Jim Power)
!9k limit is a pain but you should be able to nut it out

Cheers George
 

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raanan

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georgehifi said:
This should be very close to yours, it's for the MonolithIII from 150hz up it should be almost identical to the CLS. (Thanks go to Jim Power)
!9k limit is a pain but you should be able to nut it out

Cheers George
Many,many thanks.This is very helpful.Raanan
 
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