I own the 1.6 models and they have a larger sweetspot than the innersounds but both speakers are flat planar designs and therfore somewhat limited in their sweetspot in my opinion. You might want to listen to the Soundlab electrostats by Roger West as I believe they are made of multiple flat mylar drivers in a curved array vs the single curved mylar driver of the Martin Logan offerings. I always thought the soundlabs sounded great and had a larger sweet spot than the innersounds and threw a nice soundstage. The Maggie 3.6 speakers are also superb and cost a lot less than the Soundlabs but if budget isn't a priority you might want to listen to both. Your room setup will also effect the width and depth of your sweetspot and soundstage, so you might not hear at home what you heard at the store.
At 3 feet from the front wall you're not going to be hearing their full potential, but that doesn't mean they're not going to sound great.
You'll need to do some basic treatment to the wall behind the speakers, perhaps some diffuser panels to help give you some of the stage depth that you'll be compromising with the 3' setup.
The sweetspot is quite narrow with the 3.6's, but moving slightly out of the sweetspot doesn't compromise the sound too much. For critical listening you'll have an optimum spot that's perhaps less than a foot wide, but for more casual listening you'll have a lot of enjoyment even sitting off to the side of the speakers.
Remember that these speakers have fuses for the panels and the ribbon tweeter, so you'll need lots of good clean power to avoid clipping and fuse blowing. I know your Innersounds are pretty demanding, but I think the 3.6's are even more so. Don't even think about anything under 600 watts if you listen at fairly loud levels and your room is of average or greater proportions.
When you get all the pieces in place, the 3.6's can be a wonderful speaker.
I have my 3.6R a little over 3 feet out from the wall, about 8 feet apart and slightly toed in so that they cross just behind my head. They throw a huge soundstage, although the sweetspot is not as big as the larger Soundlabs, it is more than adequate in my 23 x 16 room. They are oriented along a long wall, with the surface behind them 10 feet high, made of textured brick. This has an added bonus of being a built in diffusor.
Innersounds have a VERY narrow sweetspot. Wide enough for one person is what my local dealer recommended. The Maggie 3.6R is somewhat better in that regard. I use the 3.6R in a hybrid 2 channel/5.1 home theater setup. With an active center channel, the 3.6R sweetspot is HUGE. Even way off axis, you can enjoy an enveloping soundfield. With only the two speakers in stereo, the prime listening area is much narrower, but 2 or 3 people can still enjoy them simultaneously.
I would like to add to Rooze's response re: power requirements. While it is true that Magnepans are at their best with high power, please keep in mind that it is current and quality as well. I have used Magnepan loudspeakers in various flavors for over 20 years from the SMG, MGIII, MGIIIA, 3.6R. I have never used an amp larger than 400 wpc to get more than adequate spl's in rooms of differing sizes, including the one I am in now (23 x 16.5 x 10). I have used the Sunfire Cinema Signature, Aragon Palladium 1K (still have those), and currently, the Wolcott P220 monos at 220 wpc. The high current of the Sunfire is wonderful, as is the high current output of the 400 wpc Aragon, but the organic rightness of tubes, coupled with the high current and wide band output transformers of the Wolcotts make the magic happen in my room. As long as the amp you are considering has high current output, stays stable at 4 ohms, remember that the sensitivity of the 3.6R is 85db (I don't know what it is for the Eros), there are a wide variety of amps that mate very well with the Magnepans. That being said, depending on the size of your room, I would look for as many wpc as your wallet can tolerate.
If you would like a larger soundstage and sweet-spot than the Maggies provide...Apogee Duetta Signatures may be of interest to you also.
Power requirements are along the lines of the Maggies...no toe-in is needed but should be at least 3ft. out from the wall and in med-large rooms only...bass response is truly full-range and will overload a small room.
Thanks for the replies.
Slipknot & Rooze -- I will using my Innersound ESL300 which from what I've read is a good amp for the 3.6s. While I'm sure there are better (Wolcotts for example) it will be a good start for me.
My room is 14x20 and the 3.6s would be on the short wall. They would be about 8ft apart. Perhaps I could leave them 3 ft out from the front wall (for aesthetics) and for critical listening, slide them out another foot or so. Are they easy to slide in and out? At least they don't appear to be very heavy.
At this point, I am leaning towards getting the 3.6s. But part of me wants to wait for the HiFi Show in NYC and check out what's new : ) VonSchweikert's VR4 Srs are supposed to be everything the Jrs are with more bass! Yeah Hah! Two months seems like an eternity now!
Thaks again for the replies!
Three feet is a great start. They slide pretty easy on bare floor so if you can move them out a tad, go for it.
As a matter of fact, you've got me rethinking bringing mine out another foot into the room. The current 3 ft 4 in. I have them out is based on the calculations Rives Audio came up with when they did my room design.
I would think that your Innersound amp will be a sweet match for the Magnepan 3.6R.
Best of luck, and keep us up to date.
I had my 3.6's at 68" for a while then was able to bring them out to around 90". It's a great improvement in stage depth and the bass has cleaned up a little too. If you can get away with it try it.
Also, if you have some foam around or something like a 2'x 2' acoustic foam panel, put it behind your speaker with one side on top of the XO box and touching the back of the speaker, and elevate the other side around 10"-12"
If you have the panels handy it'll take two minutes. You can also try it with a sheet of 2x2 cardboard if you don't have the foam.
Listen for better transparency, a wider/deeper soundstage and slightly better imaging. Adjusting the angle of the foam panel changes the tonal balance just a tad....the optimum angle depends on the height of your ceiling and the distance from the front wall, so you may need to mess with it a bit.
maggies present some interesting options for you. You can actually fine tune maggies sweetpot. Since the tweeter is a line source you can toe the speaker in or out. Or keep it paralell to the listening position. Quite different from the innersound.
I beleive putting the maggie three feet close to the wall is bad. However with any dipole you have the option of using room treatment to kill the backwave. Some even say this is mandatory.
I'm lazy so I did not do it for you. But maggies' spec sheet gives horizontal dispersion for it's tweeter. I beleive it was 30 degree arc. check thier website to be sure. They should also have some info in FAQ sheet regarding the back wave.
generally speaking the maggie should be placed 1/3 of the way in to the room about ten feet from the listening position.
divide the distance from the side walls by 4. Place each speaker on the 1/4 distance spot. fine tune from there.
I do not own these great speakers,but,would like to share an experience I had,with the hopes that you could get something out of it.
I had an old friend who was a very capable modifier who owned a pair in a room about the size of yours.He stabilized the base(easy to do),and modified the crossover(no idea here).Also,the speakers were about 4 feet from back wall,with standard treatments.I must admit that the sound was STUNNING!!!
The speakers were driven by Spectral amps,with tubes in line/phonostage.WOW!!Was this a killer set-up!My friend had a huge classical LP collection(all the great stuff we've read about).I hope,and know,you have the capability to get this level of performance.
Large,open stage with SUPERB harmonics.Deep and dynamic.I have heard a TON of stuff,and I'm not exagerating.Really convincing midbass.Deep bass was more than adequate.No weakness here,but,the overall sound was so CONVINCING that I didn't worry about how low they went."WHO CARED"!!I had no problem with any degree of narowness of sweetspot.Never ocurred to me,the sound was SO RIGHT!!
Unfortuneately,soon after that wonderful listening session,his sweet and darling wife passed on.He sold his stereo set-up and records and moved away.I'll never forget my old friend Ernie,and the wonderful sound he was able to get from these GREAT speakers!!The state of the art IMO has not moved appreciably far beyond that recollected sound!!
By the way,I have a current acquaintance, from that old group,who was given a loan of the 3.6 speakers.He owned the INNERSOUND Eros speakers you have.As of last summer he sold the EROS's and now owns the 3.6's.
Sounds a bit strange,but,I swear, every word is true!!
One suggestion if you get Maggies, keep your Innersound amps if you have them. They sound better with Maggies than anything else out there!!!
Except for the Sierra Denali's.