Martin Logan Classic 9 vs. Impression 11A - sound impressions and burn in question


Hello! I have recently had the chance to compare the two models mentioned in the same room / system and my findings are a bit unexpected, hence my post here in order to share them with you and maybe get some help with an explanation of what I've heard. This could have a great importance in the light of a possible purchase decision so please chime in with everything you've got! These being said:

- the 9 were fully burned in, the 11A had maybe 10 hours or so on them

- the 11A were definitely more detailed throughout the frequency range, clearly more relaxed / effortless, amazingly with even sharper and better defined transients, better bass extension and perhaps slightly better highs extension too; they also sounded bigger and everything was better separated, whereas through the Classic 9 things were more... gathered together, let's say (I hesitate to call this "congestion" because this is true only by comparison to the better model in the series, by themselves the Classic 9 have great instrument separation and great soundstage); the bass was also more even and better controlled. The 11A I've heard is clearly the better model from a technical standpoint, no doubt about it, but it is also comparatively a bit drier and perhaps over-controlled or overdamped in the bass, thinner in the midrange, more cerebral and I daresay somewhat less involving

- surprisingly, the Classic 9 also had some advantages: the sound was more tactile both in the bass (a fatter, punchier and more cavernous low-to-midbass injecting better drive into the music, better PRAT) and the upper midrange (some small percussion instruments, I don't know their English name, were more, well, percussive), better emulating that pleasant tactility that is an advantage of the speakers with dynamic drivers; also, they were warmer, more colorful, bloomier (for better or worse), with a hotter (usually for the better, sometimes a bit overdone though) mid-midrange (around 1 kHz I guess) and fuller lower midrange, resulting in a better reproduction of the body of the stringed instruments, the chestiness of the vocalists etc.; probably this extra body combined with the slight "congestion" (see above) made for a more cohesive presentation with better musical flow; hard to describe, the bass, while rounder and more ambiguous, seemed also in a way a bit more natural

Interestingly, Noel Keywood has reviewed both models in  Hi-Fi-World  and in the 11A's review he states that these are brighter than the Classic 9. The measurement graphs at the end of the review shows a significant dip in the 11A's lower mids that is missing in the Classic 9's graph, which overall looks closer to the Harman curve.

So, my question is which of the drawbacks I've noticed in the 11A can be attributed to:
a) lack of burn in (a bit overdamped in the bass, clearly thinner in the lower midrange, less tactility...?)
b) the DSP and A-D / D-A conversion (less natural bass, less involving?)
c) sealed drivers vs the bass reflex design of the Classic 9 (less cavernous, fat, weighty bass?)
d) a different, intentional, voicing of the two models (I thought at least the panels should have a quasi-identical voicing?!)

What changes could I expect with the full burning in of the Impression 11A?

Thank you all!
donquichotte
When you go up the Martin Logan line a few things happen. One, the crossover point from panel to dynamic drivers is lowered. They increase panel size so now the electrostatic panel can produce more mid bass without substantial distortion. They also ditch a passive crossover network and go active. The congestion you hear in the lower models is the passive crossover network affecting the sound of the electrostatic panel. The larger ML's have more panel size so you get lower distortion and a bigger more detailed sound. Not a burn in issue with 11'a's. They will sound thinner and brighter because the electrostatic panel is now covering more of the audio spectrum.  Crossover point for ESL 9 is 380 hz to woofers. 11a is 300. 400 square inches of panel for ESL9 VS 500 for 11A. The Esl 9's will sound fuller because of higher crossover point and passive network coloring the panel.  Esl 9 still sounds fantastic.  11a's have more detail, less distortion but it's up to you which sound you prefer. 
Feel free to read something I posted earlier tonight regarding 'stats and PM me if you want.

https://forum.audiogon.com/posts/1876621
@jeffvegas: What you're saying makes perfect sense, although it's not what I wanted to hear. Have you heard these two models?
@emailists: PM sent.
Thank you both. I know there are other Impression 11A users around, I'd appreciate more feedback especially regarding that lack of punch / tactility in the bass and mids and the dryness of the bass.

I am in the same dilemma. I own a pair of electromotion esl with 2 REL 5i subs.. Like what I hear but now I want more of a good thing. Do I go to ESL 9 or 11a's. After hearing a broken in pair of 11a's and comparing to classic 9 this is my assessment.  The 11a's finally start to give me that big electrostatic sound but they sounded thin and I would need subwoofers with them as the bass is not powerful enough for me. If you ask anyone the 11inch panel from Martin Logan is bright.  Actually the outgoing MONTIS model sounded better than 11as. It uses a slightly larger panel. For the sound I am looking for I will either be going with ESL 9's and a pair of REL subwoofers or I will look for a new or used pair of MONTIS. The Montis bass is not as fast as the 11a's but it is more powerful. I love the sound of the MONTIS panel. The ESL 9 is not as detailed or does it give as BIG a sound as the MONTIS or 11a's but it is a welcome improvement from my electromotion esl and the classic 9 has a warmer sounding panel than both. Dont have the funds to go 13a's but they would solve all my problems. 
Oh one more thing. If there is one advantage to the less expensive Martin Logans is that the narrow panels image better than the wider ones. My little electromotion esl actually image BETTER than 11a's. The wider the panel the more diffuse imaging gets. The ESL 9 retains the pinpoint imaging. So now I am leaning ESL 9. BUT those big panels sure throw a BIG sound and they do have more detail and can play louder than the narrow ones. Tough call. It really comes down to money. How deep do you want to go into this thing. 11A's are too bright. Its Montis or ESL9 for me.  13A's even used are 7 or 8 grand so I cant do it. 13A's are so smooth and relaxed. Almost Sound Lab quality. 
This is extremely useful, thank you so much! Before this audition I would have never guessed the Classic 9's panel would be any different to it's larger siblings from a tonality point of view, but you are totally confirming what I was hearing. What about the punch / tactility, have you noticed any difference between the two? I'm not talking strictly about the lower mids / upper bass area. Also, have you done your comparison in the same system and room?
Yes the comparison was done with same electronics and same room. The ESL 9 with its slightly higher crossover point at 380hz compared to 300 for the 11a gives it a fatter mid bass and more power through the lower midrange because the dynamic woofer is coming into play more. Conversely the 11a will have more detail in that frequency range but I just dont like that panel on the 11a. To thin, to bright. Plus I like the idea of ONE amp powering the whole speaker. With the 11a you have two different loudspeaker technologies going on AND then they put an amplifier to power 300 hz on down. Now you have 2 different amps with their own characteristics and two different speakers ( electrostatic and cones). To much going on. Plus what if the amp section goes out in the 11a. The whole speaker is shot. I just convinced myself of getting ESL 9. Unless you have to money to go 13A or 15a stick to ESL 9 with some good subs. 
You're a very convincing person, I'll give you that :). Happy purchasing and thanks again!
imo, the 11a will reproduce the signal provided by your electronics. they are neither warm or bright. they simply mirror the electronic signal. so if you like warm or hyper detail then choose the electronics accordingly. the bottom woofer compartment of the logans are easily dismantled and any problem with the circuit board ,amp ,woofer,etc can simply be sent back to the company for service.