Review: Martin Logan CLS IIZ Speaker

Category: Speakers

The Martin Logan CLS 2Z is a niche speaker. It is capable of startling depth, clarity and amazing speed. It is not just a glimpse of audio truth it is standing right on top of it. The speaker reveals every change of component, wire and even cleanliness in power. I personally value imaging and clarity; the speakers have those in spades. If the phase is incorrect, if the recording has no ambience, if there is excessive processing it is revealed.

However, the speaker also has issues. If you are a Who fan that likes concert levels look elsewhere. It will play no louder than about 93db. The speaker has no deep bass. Subsequent iterations have more of the low end but only the latest will make you think you can live without a sub. And if one runs the speaker full range it is very difficult to drive. Only amps rated into low impedance loads with more than 150 watts per channel need apply.

Did I mention subs. Only very fast subs will sound integrated with these speakers. Setting up the sub may take some time. This speakers' transient response and speed are to die for.

I have heard from some that tubes sound best with them. My experience has been that only amps without veiling sound good with these speakers. and only amps with high current ability will be able to survie their combination of capacitance and low impedance.

The reward is worth the time spent. I have heard this speaker against some highly touted designs and some very expensive designs. I have heard very few equal or surpass it in sound quality. Ithink many will play louder and without as much fidgeting to get the best sound.

To sound their best they need at least three feet from any wall and one needs to be at least ten feet away. This is not a many monitor. It does image like a many monitor but with a real image size.

Associated gear
Marantz 700's
Odyssey Stratos Mono Blocks
Adcom 555 Series I Power
Adcom 565 Pre
Electrocompaniet 4R
Genesis Metal Cone 12 Sub
Audio Pro A50 sub
Marchand xm9 electronic sub
Linn Valhalla with ittok and Sumiko Blue Point Special/ Shure V15 Series 5
NEC 830/ Audio alchemy XDP and DTI
Revox A77
Teac TN400/Stax ua7/ Shure V15/Supex 900
Tandberg 3031
Denon MR3
Musical Fidelity xlp2

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You definately need good amplification with the CLSIIz, as with any good, reveiling speaker. However, the fact that the impedance tends to range from 4 down to 1 ohm (!) makes this all the more important. I have used 2 Gryphon amps (the S100 and the new Antileon Signature) with spectacular results. For tube amps, use one that is designed to perform optimally at low impedance levels, such as the CAT JL series amps. I would recommend an amp that can deliver at least 100 watts into virtually any load - high current!

For bass, you need a very fast, fully enclosed sub or pair of subs. The best results seem to come from the REL Strata III model - not the most expensive or deepest of the RELs, but definately the quickest. I run my CLSs full range (keep the xovers from distorting the sound) and run the subs in parallel via a REC OUT or off of the amplifier taps (unique to REL).

I agree that this is not for "head-banger" music, but is also one of the most technically and musically accurate speakers you will ever hear. It's also pretty neat to look at; especially with mini flood lights mounted behind them (and pointed skyward) to highlight the see-through membrane; real cool!
A few points of clarification. the original poster mentions "later iterations". The CLS IIz is the last iteration, there is no later one.

They have plenty of low bass, its' just not overemphasized like a lot of box speakers. They go below 40hz in a good room, albeit not with the "slam" of a box speaker. I supplement mine with subs I made myself, mainly as I have a taste for bass, but they are fine full range too.

I have found they dont' need 150 or even 75 watts to sound good. I have the earliest version (CLS I) and have no trouble driving them from 22wpc SET 845 monoblocks, or the 25wpc 47 Lab Gaincard. They also work great with my Classe CA200 or CJ Prem. 5 monoblocks. more power than 20-30w is not really needed, esp. if being used with subs, at least IME.

so-called "fast bass" is a misnomer of the worst sort. There is no such thing. Bass has the same speed regardless...the speed of sound is a constant at any given elevation above sea level. What makes people think one sub sounds faster than another is things like overemphasized mid-bass response (sounds punchy and quick to the uneducated). Loose woofer control esp. in a ported design can contribute to the thought that the bass is "slow". What the real problem is is spurious port and box noise, not something coming from the front of the woofer. Inadequate amps can also contribute. But lose the whole term "fast bass", it simply sounds stupid and is incorrect. Those wanting more info should join the BASS/DIY speaker list...where it has been discussed to death.

Also a good crossover (I use a Bryston 10B sub balanced) doesn't take away anything from the quality of the CLS sound. I have run w and w/o and cannot tell a difference.

Bottom line: to me these are the best Martin Logans (save maybe the statements), and pretty much the best speakers I have heard, ever. I've owned many pairs but none equal what the CLS are capable of.

-Ed Sawyer
I like the original CLS's the best. They had the most magic IMHO, but they were also not as capable as the later versions. By "capable" I mean the later versions extended further in frequency response on both ends, were less picky about amplifiers, and had little bigger sweet spot. (well, even a couple of inches is a little bigger than the original version I had).

The pristine clarity and spooky realism of the original CLS's midrange lost something with the latter versions, IMO. One note of caution about the original CLS's though - their panels probably need replacement by now, or should have been replaced already. From what I know (don't quote me on this), the earliest versions essentially wore out after a few years. But by then, ML had gotten the problem solved, so the replacements should be set for a very long time. This part I know from first hand experience.
Dannylw, your note about subs is exactly my opinion as well. I found it virtually impossible to mate a sub. They all sounded hopelessly slow, like they shouldn't even be in the same race compared to the CLS's. Never heard the Audiopro sub matched with CLS's like you have, though I did have good luck with a Muse 18.