CLX ART Impedance Curve

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BigGuy

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Interested in obtaining an impedance curve for the CLX ART speakers.

Anyone have one to share or know of an online source where one can be had?

Thanks in advance.
 
martin-logan-clxz.jpg

http://www.hi-fiworld.co.uk/loudspeakers/65-reviews/252-martin-logan-clx.html

I don't think there's any measured difference between various CLX models.
 
Thanks, MPS.

I just found that link as well. Would be nice if the scales had been a bit more expanded.
 
Yes, the scale is not very accurate. What would you like to see exactly?
I think nominal impedance is 5 ohms and goes down to 1,5 @20kHz but you can questimate between 4-8 ohms in midrange. Experiment with 4-8 ohms taps on tube amplifier and on SS typically doesn't really matter as long minimum value is still within accepted loading range (not necessary for all D-class amps.)
 
Something a bit more resolved would be nice to have. Something like this one for the Montis...
Montis Impedance Curve.jpg

Heard that putting a Zobel Network across the speaker terminals would "sweeten the highs" with my Pass Labs XA-160 monoblocks. From what I read, an electrical resonance created by amp/speaker interaction might be eliminated or, at least, mitigated. Values of 10 Ohms and 0.22 uF were suggested.

Not trained in electronics theory or design but trying to understand a bit.
 
Something a bit more resolved would be nice to have. Something like this one for the Montis...

Heard that putting a Zobel Network across the speaker terminals would "sweeten the highs" with my Pass Labs XA-160 monoblocks. From what I read, an electrical resonance created by amp/speaker interaction might be eliminated or, at least, mitigated. Values of 10 Ohms and 0.22 uF were suggested.

Not trained in electronics theory or design but trying to understand a bit.

I thought Zopel would be more beneficial for inductive loading like typical voice coil of dynamic element. ML has no doubt exact measurements of speaker impedance, why not ask them :cool:
 
Heard that putting a Zobel Network across the speaker terminals would "sweeten the highs" with my Pass Labs XA-160 monoblocks. From what I read, an electrical resonance created by amp/speaker interaction might be eliminated or, at least, mitigated. Values of 10 Ohms and 0.22 uF were suggested.

Not trained in electronics theory or design but trying to understand a bit.


My thoughts are that if there were a way to level out the impedance without having unwanted side effects Martin Logan would have done so already.
 
I thought Zobel would be more beneficial for inductive loading like typical voice coil of dynamic element. ML has no doubt exact measurements of speaker impedance, why not ask them :cool:

Tip on using the Zobel Network was provided to me during an inquiry regarding compatibility of the newer generation *.8 series PASS amp with the CLX. It was provided to my source by a reviewer of (unspecified) Martin Logan speaker with this brand of amp. Have not been able to find any references but, apparently, some sort of electrical (not mechanical) resonance distortion can be developed by interaction of amplifiers and the (very) low impedance (in the case of CLX, 0.7 Ohm @ 20kHz) of the electrostatic at frequencies beyond human hearing capability. The distortions were reported to affect the sound quality of the (hearable) higher octaves of the electrostatic.

My request to Martin Logan for an Impedance Curve resulted in the response that the measurements were proprietary and could not be provided. When I suggested that Impedance Curves for other M-L speakers were available online, I was met with silence.

John Atkinson at Stereophile, the source of other M-L curves, indicated that they had never measured the CLX.

Calculations for the R & C values of the Zobel is predicated on knowing the impedance of the speaker at the frequency of interest. Given the 10 Ohm R and 0.22 uF C that I was provided, it might be possible to back calculate the Impedance that was plugged in initially?!
 
Tip on using the Zobel Network was provided to me during an inquiry regarding compatibility of the newer generation *.8 series PASS amp with the CLX. It was provided to my source by a reviewer of (unspecified) Martin Logan speaker with this brand of amp.
I wonder if this isn't a little bit of inapt history circling back to us. The earliest versions of the Pass XA and X amps (pre- .5) reputedly did exhibit problems with ML reactive loads. Pass claimed that this had been corrected in the .5 versions and this has been discussed here more than a couple of times.

I guess I'd be surprised if Pass had regressed in the new .8 product, but anything's possible.
 
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I wonder if this isn't a little bit of inapt history circling back to us. The earliest versions of the Pass XA and X amps (pre- .5) reputedly did exhibit problems with ML reactive loads. Pass claimed that this had been corrected in the .5 versions and this has been discussed here more than a couple of times.

I guess I'd be surprised if Pass had regressed in the new .8 product, but anything's possible.

Interesting background, RUR...sorry I missed the earlier discussions.

I AM using the pre-0.5 series XA-160s to drive the CLXs. However, my inquiry to Pass was regarding XA-*.8 series with the CLX and he indicated that it was a recent review which I assume would make the amp a *.8 but still unspecified M-L speaker.

Maybe I will follow-up with Pass for clarification.
 
One could always measure speaker impedance by himself, it's not really rocket science ;)
 
I wonder if this isn't a little bit of inapt history circling back to us. The earliest versions of the Pass XA and X amps (pre- .5) reputedly did exhibit problems with ML reactive loads. Pass claimed that this had been corrected in the .5 versions and this has been discussed here more than a couple of times.

I guess I'd be surprised if Pass had regressed in the new .8 product, but anything's possible.

RUR, can you or someone else point me to the thread(s) which discuss the Pass Labs XA and/or X having problems with the ML reactive loads? Would like to read the back story since it would be relevant to my current condition.

As luck would have it, MPS, I do know a "rocket scientist" with the necessary testing apparatus who has offered to generate for me the CLX Impedance Curve.
 
RUR, can you or someone else point me to the thread(s) which discuss the Pass Labs XA and/or X having problems with the ML reactive loads?
Will be very time consuming to find, since any search involving the term "Pass", hits every page with someone's Pass amp/preamp in their sig.

In ten minutes of searching, I found this post, which at least contains a link to tacit admission by Pass of pre .5 load issues, now fixed by .5 models.

More importantly, the XA.5 amplifiers have tremendously larger output current capacity over their corresponding XA models – more than five times the current – which is more than 25 times the power into very low impedance loads. Very difficult loudspeakers are now very appropriate loads for XA.5’s.
I know there are more, older discussions to be found.
 
Thanks for the Impedance test procedure, MPS, but will leave that to the rocketeers.

Had a fellow audiophile with a test rig run Impedance curves on the CLX, with and without the recommended (to reviewer and myself) Zobel network of 10 Ohm resistor in series with 0.22 uF capacitor. Frequency range tested was 10 Ohms - 20 kOhms. Resulting plots do not show any significant difference between the two cases.

Given that Zobel was suggested to mitigate reported effects of interaction between amplifier and M-L speakers at high frequencies, perhaps the effects are only evident with amp in play. Need to do some critical listening to assess impact. As with all tweeks, YMMV.

Have it on good authority that Pass Labs X/XA amps, either pre- or post- *.5, were ever modified to address any compatibility issue with M-L speakers.
 
Hi....It is my experience that Martin Logan chooses an amp for it's ability to handle it's wicked impedance curve rather than how it sounds. No offense intended but I never thought Krell was a good match.
I have never heard the combo but they also think Mcintosh is a good match. I would prefer a deuce of moscode 401hr running in mono.
I'll say it one more. The speaker is what it is. Subs have always been in order for the CLS. xover at 360hz means not only is the CLX not a full range design it is probably a three way design.

order pcb with components
 
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