Wondering about Panel Comparisons

DonH50

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Jun 22, 2010
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Hi all,

I am considering replacing my decades-old Magnepan MG-IIIa's. While the new 3.7 or 20.7 are obvious choices, I have always loved electrostats, having rotated a few through my system (not as owner) and listened to a variety of them over the years at friend's houses (and a few dealers). A possible upgrade to 20.7's puts me considering 'stats again...

Please bear in mind that (a) I am quite familiar with the pros and cons of planer dipoles, have a well-treated room etc. so lets focus on the speakers; (b) despite your (and my, truth be told) possible inclination to add conventional dynamics to the list, please don't; and, finally (c) price range is no more than $15k (which sadly leaves out the upper end MLs and Sound Labs designs).

Here is my short list:

Magnepan 20.7 (~$13k - $14k)
Martin Logan Summit X (~$15k)
Sanders Model 10c ($13k)
Sound Labs Millennium-3PX ($13,270)

While I love my Maggies, to my ears and instruments big 'stats have always sounded a little cleaner, but in the primordial past I found their frequency response lacking a bit (and more artifacts around the low-end crossovers to their subs than Maggie in some cases), dynamics a bit more compressed, and a number of models had reliability problems. A number of them also presented rather nasty loads, especially up high. Magnepan has always seemed a tad more colored and some models in some positions exhibited discontinuities going from high to low as the drivers were changed (not as much as most reviews would lead one to believe, at least IME), but the combination of fairly easy drive, clean sound, and good dynamics has kept me with them since the mid-70's.

I have not heard the newer 'stats. In the past I have heard Magnepan 3.x and 20, Sound Labs A-1's, ML Summit and CLX (I think; model names/numbers have likely changed), seems like an older pair of Sanders but I don't really remember, and a variety of now-defunct designs (Beveridge, Apogee, Carver Amazing, Acoustat, etc.)

Now, given the list above, what say you? Any others I should consider?

At the moment, I am leaning toward a shoot-out between the Magnepan 20.7 and Sanders 10c; I'd like an excuse to go visit Roger anyway.

A somewhat different topic for me, non-technical (well, sort-of; I am interested in the technology behind the speakers), but I have not seen (or have forgotten) a similar thread here so what the heck! - Don
 

DonH50

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Jun 22, 2010
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Have you heard the 20.7? I have a note in to see when my dealer might have a pair, but suspect it will be months.

I think the amp is only for the bass driver (?), but yeah they are something I would really like to try out. He does sell amps for the panels, a $4k adder I could not afford just now, but something I will look into. I have not heard a lot about his amps, but the little I have read has been very positive.

One frustrating thing (other than the breathtaking -- to me -- price of things these days) is not having a way to easily and locally listen to compare. In the past I had the luck of working in the biz and was able to bring them home to audition.
 

Steve Williams

Site Founder, Site Owner, Administrator
You are correct that the amp is for the bass driver and IIRC you can adjust the crossovers

I have not heard the 20.7 but have heard the 3.7 and was very impressed. I have always admired the 20.1 as a speaker so I am betting the 20.7 will be killer
 

DonH50

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Jun 22, 2010
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Yeah, I really want to hear it... I am thinking the new full-QR design should help reduce any lingering driver matching issues (which were never a big deal for me anyway) and perhaps solve the dreaded delamination issue the earlier panels exhibited, though I am not sure the QR design actually helps with the latter (a true ribbon should not delaminate, but has other issues).
 

ack

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I am considering replacing my decades-old Magnepan MG-IIIa's...

Here is my short list:

Magnepan 20.7 (~$13k - $14k)
Martin Logan Summit X (~$15k)
Sanders Model 10c ($13k)
Sound Labs Millennium-3PX ($13,270)

A couple of thoughts... I sold my MG-IIIa's used in a second system about 3 years ago - fairly colored compared to my unoptimized MLs; they showed their age, despite new ribbons every 10 years or so. But I kept them exactly because I wanted to get the same treble out of the MLs as the Maggies, which were and probably still are superior.

I've also heard the 3.6's some years ago - now that was stunning; driven by Goldmund... With respect to MLs, there are a couple of on-going mods by ML owners that I know of (mine included), and from what I have seen the execution of the crossovers is average at best, using Solen and one horrible Bennic for caps, even electrolytics parallel to the woofers instead of the more common MKP types, and not so good coils. This was the impetus for my upgrade, and take a look at these results:

Frequency response before the crossover upgrade at the listening position (subwoofer on):
Old-Crossover..jpg

After crossover upgrade:
New-Crossover..jpg

I don't think the CLX's crossover has these issues, and I don't know about the Summit X - but with respect to the latter, I wasn't getting the same ease of reproduction during at-dealer tests as I am now at home with the same electronics, my Spectral amps would shut down with the X's, and overall I wasn't liking what I was hearing compared to what I have now... If I owned the X myself, I would certainly be taking a look at its crossover as well. So careful about ML w/ original crossovers. On the other hand, the crossover upgrade has resulted in some spectacular improvements, in speed, articulation, truth of timbre, dynamics, and has offered me for the first time you-are-there rendition.

Finally, I don't know much about Sanders or the 20.7, but I think they both deserve a very serious audition. In fact, I am going to audition the 20.7 myself soon.
 

DonH50

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Jun 22, 2010
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Amazingly enough, despite modding much of my equipment and making mods to that of many others, including electronics and Maggies (mine and others'), my IIIa's are still stock. I bi-amped them most of the time so the crossover (except to the ribbon) was a non-issue.

Most of the difference in crossover upgrades I have seen I attributed to the change in crossover frequency and slope. One of the biggest changes was in the earlier units with those electrolytics, and the problem was not that they really sounded all that bad in a speaker-level application, but that they signifcantly changed value over their life (by 50% or more), shifting the crossover point. Your graphs are interesting; do you have unsmoothed versions? Reducing the 4 kHz hump could make them less harsh-sounding, and bringing up that 120 Hz'ish dip would make the bass sound better.

When I got my current Maggies (after a few others, starting with MG-I's, heavily modified), the main contenders were the 20's and B&W 801's. I really liked some of the top 'stats of the day (80's), and felt they had cleaner sound, but I already had a good tube amp (ARC D-79) that would not like the 'stat load (yes, I tried), and the 'stats of the time had other drawbacks (including integration with the woofer and limited dynamic range). By nature electrostats are hard to drive as their impedance drops at HF where most amplifiers start losing control (loop gain drops). In my room, at that time, the 20's just didn't offer that much more over the 3's, for more than 2x the price. However, the enhanced drive system and panels of the 20.1 do sound better to me, albeit at now nearly 3x the price of a 3-series panel.

Perhaps the biggest advantage of the bigger electrostats is their single panel (no crossovers except the woofer. much simpler than Magnepan) and better transient response. Of course, "better" is relative, and they are not (IMO) a huge step up from Magnepan. side by side, I prefer a 'stat; put an hour or a day between sessions, and it's hard for me to tel, especially after magnepan went to the ribbon tweeter. That was the main change that got me IIIa's instead of II's, Quads, ML, or something else.

Interestingly, I heard back from my local'ish Maggie dealer, and they suggest getting the 3.7's and spending the extra $$$ to upgrade my electronics. Annoyingly, they do not have a shipping date for the 20.7's, and at this time do not plan to stock them (even a demo) as they feel demand will be too low and the 3.7's are all most would need.

Need, yeah, maybe, but want? :)

I dropped a note to Sanders since they are also not too far; maybe I can audition a pair. I have always had a love/hate feeling with ML and have not checked to see if they have a local dealer. Pretty sure Sound Labs I would have to buy unheard, but they have crept out of my price range (the model in my range is the lowest of their Millennium series). Value-wise, Magnepan and Sanders appear to be performance leaders. I have admired Roger's work through the years, starting way back with his early designs and AA articles, and his ad copy is intriguing to say the least.
 

Steve Williams

Site Founder, Site Owner, Administrator
as I said I met Roger at RMAF and heard his speaker and was amazed when he told me the price. When he saw I was amazed, he felt that was because he was charging too much as he hastily interjected "but the bass driver amplifier is supplied with it." :)
 

MylesBAstor

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Apr 20, 2010
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I might be slightly prejudiced but it would be between the ML Summit and 20.7 (now haven't heard the new model, but had lot's of time with the 20.1s). There are lot's of tradeoffs here not the least of which is space and amplifier considerations. Both need big amps, esp the Maggie to open up. Then there's the issue of the impedance dip in the MLs at high frequencies.

Here goes in a nutshell would be my expectations: Bass is a tradeoff with Maggie probably a little faster and detailed, Martin Logan moves a little more air and has more dynamics; midrange: electrostatic still reigns supreme here over every speaker I've heard; top end, there's no transducer that I've heard that comes close to the Magnepan ribbon. (of course haven't heard the Ionovac :) )
 

garylkoh

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Even though they are a competitor, I am a big fan of Maggies and have never hidden that fact. Before I had Genesis, I had a pair of 3.5's and then a pair of 3.6's. My dealer then made the same recommendation. I compared a pair of 3.6's with a larger amp (the Classe CA-401) against a 20.1 and a smaller amp (the Classe CA-201) and much preferred the 3.6's. I eventually bought another CA-401 and bridged them to drive the 3.5's and upgraded the crossover components.
 

ack

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The dip at 125Hz is really my room; I need treatments that will also hopefully reduce the 40-50Hz hump even further. The small 4kHz rise is the speaker, adds presence and isn't harsh. Overall, excepting the 125Hz drop, I get +- 4dB variation which isn't bad. I went through this exercise to learn... and I did; I now know what to look for when I decide to replace the MLs, both in terms of frequency response but more importantly looking under the hood to analyze the crossover. They ain't selling me anything that doesn't have Mundorf or similar written all over it again... there is no high end speaker with Solens, Bennics or electrolytics, but I am sure we all knew this... Even the stock coils measured 1.5ohms resistance, while the new Mundorf CFC-14s barely measure 0.1... My next speaker has got to have an expensive crossover implementation.
 

rbbert

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Actually the Sanders amp can run the speaker full-range, he just "recommends" biamping, and throwing in the one amp as part of the package is his way of encouraging that.

I haven't heard the Sound Labs, and only the Maggie 20.1 several years ago (not the 20.7). I don't see how you can really go wrong with any of the top three, and the Sound Labs have an excellent reputation.

The King Sound speakers also deserve consideration (I'm not sure which models are in your price range).
 

DonH50

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ack, I have long suspected the biggest benefit of a crossover mod is the reduced coil resistance, since that directly impacts damping factor (amplifier control). Of course, now you have me thinking about getting my IIIa's updated by Magnepan, then upgrading their crossover... My IIIa's are pushing 24 years old and starting to show their age. They were stored for a long, long time but have been played hard the past couple of years. Magnepan will refurbish them for around $1k - $2k, which will bring them close to the 3.6 (they do not, or at least were not a year or two ago when I last called them, putting the QR panels in them, though they might be now). Given the state of our retirement fund and rising college costs (one boy over half through but another coming up) I may have to take the most cost-effective route.

Gary, your experience sounds similar to mine. The 20.1's should have deeper bass and a smoother midrange/tweeter blend with better transient response, but I did not really hear that. When I first jheard the 20's they sounded much better/bigger than the IIA's, but in a larger room with better treatment. The dealer moved the 3's into the same room and the differences were virtually gone. A dramatic example of the influence of the room. I don't think I was ever able to measure a pair of 20's. I have a pretty small room now and am unlikely to have larger in my lifetime, so perhaps I should be thinking of the 3.7's instead. That would put any 'stat I have on my list at around 3x the price of the 3.7's, probably saving me a lot of traveling and heartache about what to do. :) My main reason to consider 'stats is their crystal-clear midrange and seamless transition into the highs, but frankly I have never had the issues reported by a number of reviewers (and some owners) with transition among bass/mid panels and the ribbon. I do know the ribbon tweeter made a large difference from the II-series line when I auditioned them. Of course, I could hear over 20 kHz then; now, my limit is somewhere between 10 and 12 kHz.

rbbert, as you say Sanders bi-amps, and strongly believes in that system (as do I). The amp is used after his active crossover (provided) so buyers do not have to buy another amp. I am not sure they are set up to run full-range from a single amp. The Magtech amp is used for the (dynamic) woofer; he suggests the ESL amp for the panels. I loved the Sound Labs, probably the best 'stat I have heard, but pricey then and much more so now. I have never heard of King Sound so will have to do a bit of leg work.

Thanks guys, lots to ponder! FYI, this is because I am getting nervous about my old IIIa's; at times I fear I hear the death rattle of delamination, but it is not constant so there may be something else going on and I have not had time to troubleshoot. My wife has said to go for 20's if that's what I want (bless her!), but I really do not want to spend the money just now.
 

garylkoh

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Sep 6, 2010
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My main reason to consider 'stats is their crystal-clear midrange and seamless transition into the highs, but frankly I have never had the issues reported by a number of reviewers (and some owners) with transition among bass/mid panels and the ribbon. I do know the ribbon tweeter made a large difference from the II-series line when I auditioned them. Of course, I could hear over 20 kHz then; now, my limit is somewhere between 10 and 12 kHz.

I've never had any issues with transition among the bass/mid/ribbon in the Maggies - although it takes a LOT of power before the bass/mid catches up with the superlative response of the ribbon in the 3.6. The other advantage you have is that with the state of the economy and cost of education and healthcare, your next pair of Maggies may last you the next 20 years or more.
 

ack

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@Don... If you can, do make an effort to audition the Analysis Audio line; the construction is far superior to any Magnepan I have ever seen, and I haven't seen the 3.7 or 20.7; with sound to match
 

mep

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I love those new Maggies Don but having heard Roger's speakers at RMAF they are not only spectacular but IIRC you also get the amplifier for that abovementioned sales price

I strongly recommend this combo as well. Steve and I heard it together and I told Roger I didn't want to leave his room and I didn't say that to anyone else at RMAF.
 

DonH50

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@ack: I forgot about those (Analysis Audio) -- another full-range ribbon, and I assume the strong Apogee resemblance is not accidental. Reasonable impedance unless it drops at HF (probably still much higher than the ML's 0.8 ohms!) All but the smallest models are out of my price range, alas. Only one US dealer, on the East coast, drat! Maybe they'll be at RMAF this year...

@mep (and Steve): Got a nice email from Roger today. They are open 7 days/week, 10 hours/day to fill orders -- business must be good! I want to ask about the woofer design -- TL is a great approach, but I decided years ago servo was a much better design. I am curious to get Roger's thoughts. Their 94 dB sensitivity is impressive for any speaker, and outstanding for a planer design. I really want to give them a listen!
 

ack

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@ack: I forgot about those (Analysis Audio) -- another full-range ribbon, and I assume the strong Apogee resemblance is not accidental. Reasonable impedance unless it drops at HF (probably still much higher than the ML's 0.8 ohms!) All but the smallest models are out of my price range, alas. Only one US dealer, on the East coast, drat! Maybe they'll be at RMAF this year...

No, not all-ribbon, but like magnepans, Mylar and ribbon tweet. If you want apogees they can be had for $13k or so for a pair of divas from thalmann (the price In 2010), plus another xxx for whatever quality crossover you want. They are rebuilt with Graz ribbons and I would imagine they'd still at the top of their game. I just checked my email, and Mundorf silver/gold caps would add $3k to the price, not bad at ALL.

Between the apogees and the Analysis I would have a tough time selecting... The Analysis Omega was Jacob Heilbrunn's best of show at RMAF. Basically, you can buy top panels these days for $20k, and you can squeeze the CLX in there with discounts but you'd need subs. I wish I had the space for any of these.
 

ack

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ack, I have long suspected the biggest benefit of a crossover mod is the reduced coil resistance, since that directly impacts damping factor (amplifier control).

I don't know, but the caps had a profound effect in terms of speed of charge/discharge, thus benefiting timbres, clarity, imaging and everything else you can imagine. Since I first replaced the caps and weeks later the coils, I can say that in this case the caps offered the biggest improvement. In the end, though, it doesn't matter since I would have replaced them all anyway...
 

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