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.

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I would like to mention how perfect they are with intimate music and how articulate they are at low volume levels.

I use spm reference cable and the granite 555 into a PS audio ultimate outlet high current into its own 20amp circuit. For some reason I get a lot more air with the granite 555 than any of the eight other type power cords I have. I put the speakers on some aurios 1.2 for isolation and have them mounted 18" off the floor. If I want more midbass, I use the Shunyata python.

I use them with the Descent subwoofer.

Tell us about yours....
I agree with most of what your saying. I disagree that you need 150 watts to drive them, I'm using BC 2.1 amps with 75 watts to great effect. CLS panels will only take 60V (from manual), so be carefull 'overamping'. They sound so clean with a good system that its easy to just keep turning them up. Like you said, they don't do bass, and they don't do loud, so be carefull with the volume knob. Before the CLS2's I owned maggi MGIII's, and before that the MGI's, and I found that panel speakers always sound better along the long wall in a rectangular room. Because of this it will be difficult for most of us to be 10 ft. away. I'm (my head actually) about 8 ft. from the panels, and they're 3.5 ft, from the back wall. My equipment is tube and tube hybrid, so I don't know how they would be with solid state alone. In my room I'm getting the best sound I've heard from any of my systems, with the exception of the low bass.
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
Any thoughts on the CLS vs. CLS II vs. CLSIIz?
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.
Some other thoughts re: CLS vs. CLSII vs CLSIIz... the originals are considered better, though nicely enough they are usually cheaper. I found my pair for well under $2000, and that's with 3-yr-old panels, a recent checkup by ML and the rather rare Walnut frames.

The reasons some of the earlier models (across the ML line, not just CLS) wore out panels quickly is they had the panels charged at all times, not just when playing. Later iterations had a current sensing part to the circuit that shut the panels down after 5 min. of no music. I have mine on a switched outlet so they are not charged when the system is off. Most of hte changes from generation to generation are in the electronics box on the back of the speaker.. the panels themselves I think are pretty much identical between the various versions of CLS.

For subs - try crossing it as low as possible. I think mine is crossed at 18db/octave @ 40 hz or lower.

Anyone know which finishes these speakers came in? Black and light oak seem to be the most common. I've never seen another pair in Walnut. Have seen some in I think one other wood, but i forget which it was... I asked ML if they would make frames in maple but they said no. (Too bad, as a pair of these in a figured or birds-eye maple would be a sight to behold...) Custom frames would always be an option but probably a bit pricey.

I was wondering if anyone is using the ML etc spikes on their speakers and opinion about them.

Does anyone raise the speakers off the floor.

Do they respond favorably to a dedicated circuit?
Ed - I have seen a pair of CLSs (not sure what model) in painted white (seemed to be factory, but maybe done by owner), with black grills - ugly to me, but to each his own. Most factories won't use maple because it's pretty soft and damages easily. I've seen a picture of a pair of Scintillas in birdseye maple - gorgeous!

Yada - always spike your speakers. There are exceptions, but they're rare. Spike 'em, you'll be happy you did.
hi Nalu -

in my experience, Maple is one of the harder woods available... at least as hard as walnut/oak,etc... and with denser grain... It tends to be expensive vs. oak etc., however.

ML does do aniline dye finishes - I find them ugly too, but who knows? They do several colors... (check their site).

I have to disagree re: spiking too - I find Vibrapods to be a good thing under my CLS. (suspended wood floor in 2nd floor room.)