I have heard both back to back at a dealer demo. The 3.6 was on a Mcintosh 252 and the 20.1 was on Mcintosh 1000 watt mono blocks.
The 20.1 have a LOT more bass. They dig deep and have good output. The midrange is not as forward on the 20.1 and a little more laid back. The highs sounded the same to me. I actually really like the forwardness of the 3.6 midrange, it makes vocals standout.
The 20.1 are a big up grade in sound quality. But $13,000 is a lot to spend on Magnepans with their sub-pare build quality...
I moved "up" from the 3.6s to the 20.1s and like James63, I noticed way better bass and an overall fuller sound. They were purchased used for about $8,000 and I have never regretted the move. Your room should be plenty big enough to let them perform the way they should. Mine are driven by a pair of Krell fpb 350's and even with that, I think they could stand twice the power. Mye stands are, IMO, a requirement for getting the most out of Maggies.
Go for it - you won't be disappointed.
You might be using a different amp now but if you are still using the VTL MB-125, you can forget about the 20.1. They need a lot more current.
I would most likely buy a used pair. I'm with you on the power requirements; I only use my VTL 125 MB's for my Khorns (which I keep in the same room as the Magnepans. One nice thing about the Khorns is that they sit right in the corners, out of the way)...
For the 3.6's I picked-up a used NAD C 275BEE stereo amp; it is really very good, especially for the money! It puts out 150W continuous and has plenty of head-room for brief peaks up to 450W into 4ohms...probably not as good as a big Pass Labs, but it costs a lot less! Eventually I would like to get a big Pass, maybe a X250.5 or a X350.5 or maybe even a XA60.5... I have also heard that the Cary 500MB (1000 watts into 4 ohms) sound great with the Magnepans...
The NAD won't be enough. You need more. The best I have heard driving 3.6 is Classe CAM 350 monoblock. It has been discontinued. They sold for around $7,000 new so you should be able to find them used for less than half.
Now I think about it. You might be better off keeping the 3.6 and getting a new amp than moving to 20.1. Your 3.6 has been under-driven. You have not had a chance to hear what it can do yet.
Well, that is one option I have been debating... not sure which I will do first, a better amp or a pair of 20.1's.... probably a better amp though, so that I can see what the 3.6's can really do...
The 3.6 midrange driver is larger than the 20.1, and IMO they have superior sound, discounting the lower bass response!
I do not care for having magnets on both sides, in the push-pull configuration.
I would pick up a new amp first, before you buy the 20.1's, you will need it to dry the 20.1's anyway.
Many amps would be upgrades: the Cary's you mention which I have and love, Parasound Halo JC-1's (great), varios Sanders Sound (or older Innersound ESL amps), the Wyred4Sounds, Spectron (not my fav, but lots of folks love), the Bel Canto Ref1000's, big Pass or Classe are always great, well, they are just great period.
I don't like the McIntosh amp sound with Maggies, just my taste.
That all said, and I also own the 3.6R's, I think the 20.1's not only have more bass, but are top to bottom more coherent, have great seperation of instruments, and a bigger soundstage.
In my opinion, and it's worth what's being paid for it, I think the 20.1 is the best speaker I have ever heard, period.
Get the amp first, that may improve the sound enough for you to wait, but by all means, move up if you wish. I think I may do the same thing next year.
Another option is adding a subwoofer. I know that some here will not be receptive to this idea, but I've had more than a little success with my Maggie+subwoofer set-up (at least for my taste).
I used to own 3.5s and currently own the little MMG, which I sometimes use with 2 Rythmik subs and a Velodyne SMS-1 controller (which optimizes sub/main integration and room corrects the bass response from the subs). I also use an NHT active x-over to roll off the bass on the MMGs (the SMS is NOT in the main signal path). Overall I prefer the current SMG + subs to my old 3.5s and suspect that 3.6s with DRC subs might make a formidable combo.
Just one more option to consider.
do the Cary 500 MB's ever seem to run out of steam driving your 3.6's? What do you like the most about them? Did you compare them against other high-power amps before you purchased them?
You have an interesting point about the midrange on the 3.6 vs 20.1s. I honestly like the mids better on the 3.6 for lack of a technical reason. I just keep my comments to myself though because I have only heard each of these speakers for a few hours.
Can you give us anymore details on why you feel the 3.6s midrange is better in sonic terms? I felt the 3.6s had more midrange energy and life but I could not put my finger on it. I needed a longer demo I guess.
May I know where I can read more on the DRC subs? In particular why would the synergy with 3.6.
Zoltm, (sorry if wandering OT here)
Velodyne web site for the DD series subs or SMS-1 sub controller
SVS web site for their DRC sub controller
JL web site for the (more limited) DRC feature in their subs
I'm sure that there are more - but you can start there. Also search these threads for "DRC subwoofer" - I've participated in more than a few discussions of this subject.
I have no experience with 3.6R's, but I have used Cary 500MB's with my 1.6QR's for about 1.5 yrs. I bought the amps anticipating a move up to 3.6R's, but they have been such a wonderful upgrade that I decided to put my purchase of 3.6's on hold for a while. I think the advice you are getting on upgrading the amp first is good advice. On the Cary's, these amps are just so smooth and sweet you can't help but love them. And at 1000 W into 4 Ohms they drive the 1.6's with ease. I can't see myself ever letting go of mine.
They never run out of power. 1000 w into 4ohms, that's big.
Amps, not all but a list that I have tried with my Maggies, and owned most of them, in order of how I liked them.
Cary MB 500
Bryston 7b sst
Parasound Halo JC-1
Bel Canto Ref1000
Spectron Musician III
there were a few more, but those are the usually suspects.
The bigger Pass Labs the 350.5 and above sound great, as you would expect.
Good info on the Cary 500 MB; I would probably have to buy them without a personal audition in my rig and that makes it a little more difficult to make the leap... I do keep an eye out for a good used pair but they only become available infrequently used...
you know, the thing about the Cary's is that they don't come for sale very often. So if you buy them, then don't like them, the market is very good for them, and I doubt you will even be out the shipping. I know I could sell mine for more than I paid originally, but I don't really want to.
Give the 20.1 a lot of listening before hand , setup is critical and time consuming , x-over updates are a must , you could be going backwards over a 3.6 ... if you are not willing to put in the time...