Adjusting speaker positioning. What, if anything, to expect?



I am going to adjust my Magico A3’s positioning a little bit to try to optimize their performance and the listening experience. Due to the logistics of the room they’re in, there’s only a limited amount I can move them. I’ll describe the room and what I can do within those limitations. I’m wondering what improvement I might be able to achieve with adjusting positioning.

The room is approximately 14’ x 22’. There is a high vaulted ceiling. about 15’ at it’s peak centered in the room on its horizontal axis. Picture how kindergarten child draws a house. That’s the shape of a cross section of the room and vaulted ceiling.. The speakers are located about 8’ apart centered on the long wall. The front of the A3’s are only out 22" from the wall, the rear of the speakers only 9" from the wall. That can’t be helped. The prime listening position is on a couch about 10’ out from and facing the same wall, also centered. The components are on shelves centered and built into the same long wall the speakers are on. There are some other furnishings, and books above built-in cabinets, line most of the other three walls.

I can move the speakers about a foot farther apart or closer together, and I can change their toe-in. What changes, if any, might I be expecting or hope to achieve moving the speakers within these limited parameters? Could the sound-stage be affected? I’m not sure what the sound-stage should be like anyway. Should it extend to the left or right outside the speakers, or be mainly between the speakers? Right now depending on the recording the vocals and instruments are usually between or no further apart than the actual speakers. Could the treble, midrange, or bass response be augmented or diminished depending on positioning? Are there any other factors that may be affected by positioning alone? Thank you for any guidance and please feel free to ask any questions. Thanks,

Mike
skyscraper
I can move the speakers about a foot farther apart or closer together, and I can change their toe-in. What changes, if any, might I be expecting or hope to achieve moving the speakers within these limited parameters? Could the sound-stage be affected? I’m not sure what the sound-stage should be like anyway. Should it extend to the left or right outside the speakers, or be mainly between the speakers?
Two things to keep in mind: speaker placement for imaging is almost entirely about absolute symmetry. You want to sit exactly the same distance from left and right, and with exactly the same amount of toe in. That’s one thing. The other one is tone. Big flat surfaces (walls, floors) tend to reinforce lower frequencies.

So what you do first is don’t worry about imaging but just listen for the bass and lower midrange balance. Try them closer, try them farther apart. You will probably notice a difference, even within the tiny range you have to work with. Leave them wherever you like the bass balance best.

Next take wherever they are and tweak and measure to get them symmetrical- equidistant, and also equally toed in. Listen for a solid center image, but also pay attention to the whole presentation, how deep and wide it is.

Now if you toe them in to where they are pointed straight at you the sound stage will be very solid, especially the center. Toed out and the stage will be more spacious, but probably not as solid. Make small adjustments in and out until you find the balance you like. There is no right or wrong. Its all about what you like.

The one thing you do want to be very careful about when doing this is perfect symmetry. Check carefully that they are toed in the same amount on each side. Even a small difference will result in a weaker image and if that is what you want then fine. But you do not want to be going for a holographic sound stage and then blow it with speakers all cock-eyed, and by cock-eyed I mean not inches but tiny fractions like 1/8". 

This is just the merest beginning, and focused on imaging because that’s what you asked about. But toe in also affects frequency balance, as most speakers sound a bit different off-axis than on. So you’re listening for that as well. But that’s why you go back and forth, take your time, play different music, tweak, listen, tweak, listen. 

Eventually you will find where you like them best. Then you can move on to putting them on cones, tweaking the room (if you’re able) or equipment (not only acoustic panels are acoustic, you know) and cables. Tweaking and fine tuning, there is no end. But this is the way to start.


Textbook Nearfield Listening Positions as described.
Try changing the distance between the Speakers.
The A3s are much larger than my stand-mounted mains.
Also the 15' vault should really help with A3s. 
My experience suggests closer would be right.
From 8' to 7' and leaving the listening position the same.
You should experience a sense of more power and greater depth.
As a goal anyway.
Before changing the spacing though do experiment with toe-in.
Go to zero toe-in (and any between) in the current position and listen for a bit.
Get an idea of what your sense of the sound is.
You may also experience some difference by moving the A3s toward the listening position.
Move the Sofa out of the way and Stand away from the back wall at an
equal distance to that of the Baffles from the front wall.
And listen for a bit.
The final positions could be inches in either direction (short axis/width).
But get a sense of what the sound does in the space.
Decouple the A3s if you have not done so and if the room is Lively / Bright (hard and harder surfaces) start thinking about treatment.
Once you have a good idea of how the Loudspeakers integrate then you can fine tune. 



Closer to the rear wall is going to reinforce bass response. You are pretty close, but mentioned that is your option. So be it. As mentioned, at the end of the day, it’s about personal preference. You mentioned you were not sure about sound stage and imaging. Sit in your selected position with your eyes closed, point to where you hear the main vocal track. A good vocal recording is helpful here. If you are pointing dead center and possibly slightly upward you are off to a good start. You speakers should be “invisible” to your ears. You should not be able to hear either speaker is a singular unit. Perhaps an instrument on one side or another, but not the speaker as a whole. To find your sweet spot, I suggest getting a chair on wheels and as MC said, put it equidistant to form a triangle. Then slowly move back and forth and see where your favorite position is. That way your head height remains consistent and relative to your final listening position. Mostly have fun with it. 
Thank you very much for the detailed explanation, Millercarbon. Would you mind clarifying some of the terminology you used so I can follow what you are saying carefully. What exactly do you mean by "imaging". I’ve heard the term used many times, but never had anything but a vague or loose understanding of what it means. Also when you refer to "bass and mid-range balance" what are you meaning? I’m only guessing, but Is it the amount of one in relation to the other, or something entirely different?

As you suggest, I will be careful to keep everything absolutely symmetrical to the 1/16" inch if need be. Thanks for pointing out the need to be that exact.The current set-up when you sit in the center of the couch is an equilateral triangle with the speakers 8’ apart on center and the listener eight feet from the front of either when seated. Does this sound like a reasonable arrangement? The speakers are toed out a bit from that, so I’ll toe them in as you mentioned so they are pointed directly at the listener’s head to have a solid center image to start with, and proceed from there.

There aren’t any big flat open surfaces to contend with, unless you count the vaulted ceiling, so that shouldn’t be an issue. The floors are oak, but the area in front of the couch and speakers is covered with a thick (Persian) rug the width of the couch.

One last question for you or anybody. How far should the sound stage extend beyond the speakers, if at all? I read somewhere on site the sound stage should not extend to the left or right of the left and right speakers unless they are wired out of phase. Is that so? The sound stage now often seems to emanate from inside the shelf area holding the components between and in back of the speakers.

Again, thank you,

Rego and geof, your posts came in while I was writing this response. I will get back to you in the morning as it is getting quite late and I have to call it quits for tonight.

Mike
Mike, Imaging is the ability of a system to recreate the location, size and depth of instruments and voices. It is what stereo is all about. Whether or not a system can do this well depends on the type of speaker and acoustical issues with the room including speaker placement. Dynamic speakers like yours radiate sound over a wide area creating rather loud early reflections off the side and front wall. Early reflected sound arrives at your ears just after the direct sound from the speaker blurring the image like an out of focus picture. This is the problem with the smaller rooms we tend to put our systems in. Late reflections like off the rear wall (other side of the room) are heard more as an echo. They are also much lower in volume. Late reflections do not blur the image and can make your room sound larger if the early reflections are controlled. Bass is another issue altogether. Anyway there are threads that discuss finding and controlling early reflections. Moving the speaker will change the location of these reflections. Moving  speakers like yours farther away from the walls diminishes early reflections and improves the image but decreases bass efficiency. This is a strong rational for using separate subwoofers and the reason many audiophiles keep their speakers so far out into the room. You can sort of have the best of both worlds if you keep the speakers right up against the wall and deaden the surrounding wall with acoustic tiles or panels. Millercarbon is an old school symmetrical guy and for speakers like yours I think he is correct although there are some like Roger Sanders that would argue with this. With speakers that are very directional like horns symmetry is not as important. My system set up is perfectly symmetrical because my brain won't tolerate it any other way. It also can't stand to see a crooked picture. My speakers are ESLs and they are also very directional. 
Anyway, when you move your speakers around pay close attention the image. Instruments and voices should be very distinct and float in space.
Close your eyes. It should sound like the band is right in front of you. 
As I oft counsel the method of moving speakers a little one way or the other and listening each time you move them is far from ideal and can only result in finding local maximum speaker positions, at best. You cannot find the absolute best positions for both speakers that way. The only way to find the absolute best positions for any speakers in any room, regardless of room treatments and regardless of the rest of the system, is to use the speaker set-up track on the XLO Test CD or similar test CD. It’s the out-of-phase track. When you get the most diffuse sound using the out-of-phase track you will get the most focused and correct sound when the system is in phase. Even as your system evolves the speaker set-up track can be used again to establish new best speaker positions. Trying to find the absolute best speaker positions by trial and error is like trying to solve x simultaneous equations in x + n unknowns.
Geoffkait, you automatically adjust phase when you listen for the image. Adjusting phase is only important when you have separate drivers such as subwoofers. Think about that. You can move your head side to side and find the exact spot where two speakers are in phase. It is where the image snaps into focus. This of course is the listening position. Phasing subwoofers is certainly more complicated and the best way to do this is by measuring arrival times which requires a microphone and a computer set up for impulse testing. 

Interesting idea to use an out of phase track, I've never done that but it's worth a try. But you don't need to buy a special cd, you just swap the wires over on one of the speakers to invert the phase. When the speakers are perfectly out of phase it sounds like there's a gaping hole in the middle of the sound stage.

When you're looking for a good spot for bass response then you can put the speaker in your listening position and use your ears to find a spot with the most natural response, then you put the speaker driver (along with the speaker obviously) in the position where your ear was. This is mostly used for subwoofer positioning but there's no reason why it wouldn't work with a conventional speaker.

For me, toe in is most noticeable in the highest frequencies as they drop off quite sharply off axis. Also avoid having the bass driver/s in a position where it is equidistant from two surfaces (floor & wall, side wall & back wall etc.)

Buy a laser measurement device. I think I paid $ 80.00 for mine and I use this for other projects as well.
I also think it easier to LISTEN for the best image rather than LISTEN for the most diffuse sound. Most of us adjust our systems by "educated" trial and error. If you are unhappy with that get a good room control system such as the Anthem or Trinnov units which you can operate via computer programs and you can see exactly what your system is doing. No trial and error.

mijostyn
Geoffkait, you automatically adjust phase when you listen for the image. Adjusting phase is only important when you have separate drivers such as subwoofers. Think about that. You can move your head side to side and find the exact spot where two speakers are in phase. It is where the image snaps into focus. This of course is the listening position. Phasing subwoofers is certainly more complicated and the best way to do this is by measuring arrival times which requires a microphone and a computer set up for impulse testing.

>>>>I’m pretty sure we’re not on the same page. I don’t think we’re even looking at the same book. 😬 Oh, it’s a long way to Tipperary. 🤗
Rather than asking for opinions before you take action, why not just move the loudspeakers around and see what you think is happening?  Try different locations, toe-in and tilt angles.  Take your time for this could take months of listening.  If it helps, take written notes.  Everybody has their opinions about what will happen, but only you are in your room with your loudspeakers listening with your ears.
onhwy, all that is true but there are many people who don't quite know what to listen for. None of us did when we started down this road. We learned over time. It never hurts to share this knowledge with people who are just getting started. 
Goeffkait, we are never on the same page. Pick your poison.
I looked up the recommended distance from the back of the speaker to the wall behind it and magico has it at 20 in. Yours are at nine inches this could cause bass issues and also affect your mid-range. I would also put a level to the top of your speakers to make sure that they are perfectly level. Also distance measured between speakers should be from the Center of the Tweeter to the Center of the other Tweeter. Make sure your measurements are exact. Once you've got the speakers to your liking I would call gik acoustics, and give them your measurement stats, and describe your sound issues, than ask for their recommendations 4 acoustical treatments. Best of luck
Great speakers in a compromised situation. Looks like nice speakers in a living space, like many?

Try everything suggested, trusting your ears. No one here, has the answer.
Read,and hear other systems.

Your speakers deserve a dedicated space with room to breath. 5-6 feet from the back wall, 3-4 off the sides, firing down the length of room, with room treatment.

Anything short of that, accept reality- those speakers won't perform as intended.
You will get to an acceptable level, but not without trial and error.

My speakers location is heavily constraint by my desk and the wall configuration... It takes me months of room treatment, and acoustical space controls , to compensate and gained a marvellous immersive imaging...

(Room treatment with absorbant or reflective materials and acoustical space modification with Schumann modified generators and controls with Helmholtz resonators or different resonators and reflectors are not the same thing)

Laws exists that explain why... But I cannot pay an acoustician, and at this times I did not own a room and speakers controls software...


The method I use was a step at a time, always increasing my positive impression using my ears... The results was more than just good at the end...
@needfreestuff,
as stated; "The front of the A3’s are only out 22" from the wall" indicates that the placement (current) is approximately at a ’recommended’ distance.
1"-5" in both directions (from 20") could make a difference.
Measurement is to the Baffle and on centerlines (OC).
Would you please share your reference for "recomended" ...
@onhwy61, I think that I have already suggested this much (with exception of tilt angle).
"Rather than asking for opinions before you take action, why not just move the loudspeakers around and see what you think is happening? Try different locations, toe-in and tilt angles."

Pragmas, it is quite true that a speaker's high frequency performance changes as you move off axis. This varies depending on the type of drivers used. Toe-in is important to stabilize the image as much as possible. Point your speakers straight ahead. Now as you move from one side to the other the speaker you move towards gets brighter and the one you move away from gets duller destabilizing the image. If the speakers are pointed directly at you as you move from one side to the other the frequency response of both speakers changes in the same manner resulting in a more stable image. Irregardless the best image is always going to be when you are in perfect phase between the speakers which is usually dead center between the two. 
I think this has been missing, so far, IF you are insisting on trusting your ears (alone):

Pick a piece of music that you are very familiar with,
and enjoy listening to.  Pay attention to parts (sections) of the piece
you like best.  Focus on the sound, and how the sound changes,
from a single voice or instrument, as the song is playing.

Take some breaks so fatigue is not a factor.  Keep your listening position the same (no cheating), as this is a whole other variable.

OK to take notes, recording starting point and your listening impressions.
Writing down the change in positioning, how did this impact the sound?

It's just like getting an eyeglass prescription, when the examiner is
flipping the lenses and asking for your responses, right?
There are no set rules on speaker placement. There are too many uncontrollable variables involved. The permutations are endless.
Most people just stick the speakers where they fit into the room aesthetically without regard to the sound quality.  While it is true that dynamic speakers usually image better away from the walls I have heard installations where the speakers were right up against the wall and with appropriate use of acoustic treatments sounded quite good. There are certain speakers that you certainly can not do this with such as dipoles and speakers with rear firing drivers. Subwoofers are always better off against a wall or in a corner. 
There are a lot of variables. You can say that again, Boo Boo! That’s why people need to use the out-of-phase track method. Because that method ELIMINATES most of the variables and is guaranteed to ALWAYS find the ABSOLUTE BEST speaker positions. Hel-loo! That means it IS a set rule, as you say. It’s all the other methods that are not set rules. I guess I must not have been clear the other fifty times I described this method. 😃 Thick as a brick. 🧱 Caveate: Most rooms are in such bad shape acoustically that many people will have difficulty hearing the “sound coming from all around you” with the system in reverse polarity. It takes a lot of effort before that happens. As Bob Dylan says at the end of his records, good luck to everyone. I never said it was going to be easy. That’s why they call it a hobby. 🤗 Yes, I know, your system sounds fabulous! 
I think Geoffkait is right about using a software for the speakers and for the room, in Foobar 2000 it is a component : Mathaudio room E.Q. 2.7.6. We need to buy a mic...

But I had not used it, I will test it this summer...

Anyway others are right that some results by trials and errors using ears can gives good result...The immersive imaging I had at my 2 listening positions is proof of that...But I think optimal results are impossible without advanced tools... Ears cannot  help much to compensate mechanically for example for the interferences between the resonant speakers and the resonant room...Some corrective device must play this role...
Rego I’ll try your suggestion of moving the couch out of the way and standing a bit from the wall. I can also try having no toe-in just to see what that sounds like. Interesting suggestions to start to get a feel for the sound. Moving the speakers closer together to seven feet apart would be great and an aesthetic gain as well for the room decor, especially as opposed to moving them out to nine feet apart which I was hoping not to have to do.

Could you clarify what the word "Baffles" means. Is this another word for speakers or some part of of them. And what do you mean by "decouple the speakers"? The room decor does take precedence and acoustic treatment will not be in play. I’m not thinking there will be any need for any anyway. Thank you for your suggestions.

In response to your second post, should I be measuring the distance from the wall from the front of the speaker, rather than the rear as assumed distance from the wall meant? That would be a much more favorable measurement to go by.

Geof, the vocals are usually dead center with occasional variation depending on the recordings. I’ll try the chair on wheel out when the couch is pushed out of the was as rego suggested with the desk chair im sitting on rirgt now as I type this reply to you.

Miijostyn, thanks for your explanation of imaging. Here’s something I don’t understand about it and why I’m inquiring if the sound stage should extend beyond the current eight feet between the speakers. If you were listening to a live band or orchestra there would be well more than eight feet between the musicians on either end of the stage. That would seem impossible to recreate except in miniature in you living room. Also most studio recordings are done with the musicians separated or partitioned from one other, or recorded completely separately. it would seem the imaging in that case is solely the construct of the producers or sound engineers.

Geoffkait, I’ll get hold of an XLO test CD as you suggest. Is it the Sheffield one you are referring to? That name came up when I googled XLO test CD just now. Thanks for the suggestion. That should be helpful.

Pragmasi, I could try the switching wires out of phase trick you mention for an experiment. There shouldn’t be any issues with the speakers having equidistant spacing as you mention but thanks for the heads up on that score

onhwy6, I will do some experimenting with the positioning. I’m trying to get a clue about what factors should be in play, what I should be looking to accomplish, and what might be going on. I usually am self taught, but there is so much knowledge and experience here on site it would be a shame to not take advantage of what you all know.

Needfreestuff, thanks for the tip on measuring between tweeters.I wasn’t sure where to measure from. Before I purchased the Magicos, knowing I couldn’t move them out any further from the wall, I contacted one of their VP’s to discuss this issue. Part of why I chose the A3’s was they are un-ported. The VP said they could go as close to the rear wall as 7" but were best placed 20" out as you point out. One day I hope to add a separate Music Room to the house were they can be better situated to avoid the bass and mid-range issues you cited. I could move them farther out now, but I’d have to vault over them to get to the rooms on the other side of the house.

Tablejockey, yes life is filled with compromises. Maybe one day I’ll get that music room built. I still have some old papers on room acoustics from Klipsch from their "Dope from Hope" series copied fifty years ago on dealing with how to design that music room. It’s on my bucket list, just like getting an expensive stereo system was. I’ve made that one come true, so who knows.

Mahgister, sounds like you should come over and set my system up. I’ve a big Federal style library table to deal with in the listening room, just like the desk you ’ve had to deal with. And with room treatments out of the question. for aesthetic reasons I’ve that to deal with also.

Sgordon. thanks for the practical advice and warning about no cheating. It makes sense to use familiar recordings too. I’ll do that.

Thank you all for so many well thought out and helpful responses. I’m looking forward to utilizing your ideas as best as possible.

Mike






This message is for Rego. The recommended distance for magico is from the back of the speaker. Not the front of the speaker. Warmest regards Joe
Thank you very much for the detailed explanation, Millercarbon. Would you mind clarifying some of the terminology you used so I can follow what you are saying carefully. What exactly do you mean by "imaging". I’ve heard the term used many times, but never had anything but a vague or loose understanding of what it means.
Imaging is one of many audio metaphors. One thing they all have in common, they have to cover a wide spectrum. Another is they’re often used by people with little experience. So no surprise if it seems vague.

At one end of the spectrum of imaging you have the sense of the singer being somewhere in between the speakers. This is one small step up from where it sounds like its coming from both speakers together and spread all around in between. This is not very good imaging and would be called diffuse, vague, or my personal favorite, crap.

Way on over at the other end of the spectrum you have the jaw-dropping sensation of a live human being actually being there, and it is as if the speakers no longer even exist. You stare in disbelief and wonder if they are even working. This imaging is called palpable presence. The image isn’t just a location, its lungs and chest and throat and mouth and lips, and yeah this is partly imagination but you can reach a level where imagination is hardly even a factor any more, you are gonna experience this whether you want to or not. Michael Fremer’s term for this is there’s more there there.

The whole range in which this imaging happens, left to right and front to rear, is the sound stage. At the low end different instruments are somewhere sort of to the left or right. Sometimes you might tell them apart but a lot of the time they’re all mixed together. We say the sound is congealed. At the high end each and every individual instrument is clear and distinct in every respect from its harmonic signature to its location and even the way the sound it makes echoes around the acoustic recording space. When every individual source is clear and separate and distinct this way we say the imaging is precise or there is air around the images. Air as in space. But you have to watch out, because a lot of these terms are thrown around by noobs who have different ideas and equate air with top end extension, which is a whole different thing. But hey, it happens. So watch out.
Also when you refer to "bass and mid-range balance" what are you meaning? I’m only guessing, but Is it the amount of one in relation to the other, or something entirely different?
Yes its relative. Since you don’t have a lot of room to maneuver and since speakers are a hassle you can experience this just fine with a laptop or even a cell phone. Play some music and hold it out at arms length. Then walk over by a wall, or place it on a desk, anything like that, you will hear the sound change immediately. Same thing happens with all speakers everywhere. Put em where you like em.
As you suggest, I will be careful to keep everything absolutely symmetrical to the 1/16" inch if need be. Thanks for pointing out the need to be that exact.The current set-up when you sit in the center of the couch is an equilateral triangle with the speakers 8’ apart on center and the listener eight feet from the front of either when seated. Does this sound like a reasonable arrangement? The speakers are toed out a bit from that, so I’ll toe them in as you mentioned so they are pointed directly at the listener’s
head to have a solid center image to start with, and proceed from there.

I get a lot of flak for saying this but precision symmetry is all. My fallback is the framing square and tape measure. One year at CES we struggled for hours until I used a tape measure and framing square. Boom. Done.
One last question for you or anybody. How far should the sound stage extend beyond the speakers, if at all? I read somewhere on site the sound stage should not extend to the left or right of the left and right speakers unless they are wired out of phase. Is that so? The sound stage now often seems to emanate from inside the shelf area holding the components between and in back of the speakers.

Yeah, you will read a lot of stuff somewhere on this site. The worst are the ones that get just enough right to hook you into thinking they are helping only later (if you’re lucky) realizing they led you far astray.

Don’t waste one second worrying about this kind of stuff. Ultimately your goal isn’t to be wide or deep or palpable or any of that. Your goal is to be the recording. Whatever that is. For good or for bad. Whatever moves you even a little bit away from feeling like you’re listening to a really good stereo and a little bit closer to feeling like you are there, that is what you want. And there’s a lot more to it but this is where it all starts.

Geoffkait, thanks for the clarification on the XLO versus the Sheffield test CD and the link you provided. Is yours literally made of gold like the one in the link says it is. What next?

Millercarbon, thank you again for your detailed answers to my questions . I’ve a better understanding now of what imaging is. And I’ll break out the framing square and tape measure to get those measurements correct. I’ve some machinist calipers that could easily get those measurement exact to the thousandth of an inch, so carpentry type measurement tolerances are easy pickings.

So, if ii read you right, you feel a sound stage where the instrumentalists and vocalists appear to be located outside of the speakers, but between then, would be an acceptable outcome, and not a thing to worry about? I thought something might be wrong if they did not appear to be spread out more across the front of the room as they would be in a live performance setting.

This is kind of new to me so I probably am focusing on something regarding sound stage that doesn’t really matter, like you said. I am trying by this thread to sort out what does matter and what I should be paying attention to and trying to achieve. Thanks for your help in that regard and taking the time to offer explanations.

Mike


Careful skyscraper, you have unwittingly stumbled into the geoffkait zone, a region of endless confusing possibilities masquerading as science.  

I have the XLO CD. Perfectly set up the out of phase will indeed seem to be coming from everywhere and nowhere. Even more amazing, there's another track where Doug Sax stands in an empty room talking and hitting a clavis. He walks around the room talking and hitting, and if you're set up right its just uncanny, especially when he goes behind you and damn if it doesn't sound like he's behind you! 

Getting this done the way they say on the CD, moving one speaker or the other a little at a time, that's what the CES guys tried, and I wish you good luck. That's the difference between trial and error and a more systematic approach:  You might get there, eventually, vs you will get there, and fast.  

This might be a good time to reflect on the wisdom of taking advice from a guy who refuses to post his system, famously brags has no speakers, and no wire, and claims if you pay him money he will make your system sound better while talking to you on the phone. Seriously. The Teleportation Tweak. I am not making this up. http://www.machinadynamica.com/ Read him at your own risk. 

Just do like I said. Get the speakers perfectly symmetrical. Point them straight ahead and listen. Point them straight at your head and listen. Few of us like them pointed straight at us. Most like them aimed at a point a foot or two further back. That is, toed out a little. That's me. Some like them toed out even more. Who knows, different room, different speakers, I might go for that too. Go and listen. You will see.






For what it's worth, I prefer a sound stage that extends beyond the speakers; ie, to the left of the left speaker and to the right of the right speaker.  I agree with the comments that say the singer should be anchored midway between the two speakers, as though they are standing in front of you.  In the end, there is no right or wrong here, it's just what gives you the most enjoyment from your music.  But don't have the soundstage coming from the ceiling; that would just be wack...
The Baffle is the entire front panel of a Loudspeaker (the surface that the drivers are attached).
The Baffle is also significant with regard to Radiation Pattern and how (in the case of) the A3 integrates in a room. Do not worry about this.
Your primary concern is to listen for the differences in positioning.
Exaggerate the spacing a bit to experience the difference.
Six feet is close to a limit for spacing.
Seven feet (7’) is only a reference for illustration.
"How to Isolate Speakers" https://www.youtube.com/watch?v=dW9-r83IvhI Illustrates physical decoupling. Thanks Townshend!
A direct Physical contact to a wooden sub-floor will transmit vibration in both directions! Isolating all Audio Components can help make improvements.
Decoupling is something to be aware of while you are focusing on improvements.
Using low friction pads under the spikes to slide the Loudspeaker on a carpet (for example) would decouple the A3.

A reference point for measurement is a common question and not often specified.
The centerline on the edge of the Baffle in the vertical axis is the reference line.
Measure to / from any common point to the wall as it suits you though.
Use string and a marker if you so choose.
A throw rug on a tile floor could make a substantial difference in a
’Bright Listening Space’.


Why not put the speakers on the 14’ wall and use the 1/3 speaker position which is placing the front of the speaker 7’ from the back wall and put your chair 7’ from the walk behind the chair.
i actually have the same room length as you but a couple feet wider and I have my ushers 7’ from the back wall but I have my chair 4’ from the back wall. Give your speakers room to breathe. I also have room treatments for all corners and 1st reflection points
Ncdogdoc, thanks for the link, that’s about $30 less for the XLO test disc.

Cheeg, how due you get the sound stage to extend outwards without being out of phase?

Rego, thanks for your clarifications and the link to the Townsend video on decoupling. That was interesting. For a second beforehand I thought you were referring to a Pete Townsend video and wanting me to smash my speakers with a guitar to decouple them.

Rbstehno, the position of the doorways and the built-in cabinets below the bookshelves on the short walls precludes putting the speakers on the short wall. Also the flat screen TV is located above the stereo component shelves between the speakers on the long wall, and the couch needs to face that direction. On the short walls the TV would cover the built in book shelves if placed there. Other than that no problem. Your arrangement that way probably sounds quite good I'd imagine in a similar sized room. It's unfortunately just not possible here without some drastic remodeling.

Mike
@skyscraper, that would require a Guitar also ...
Note to myself ... Listen to more Pete Townshend!
The best deal on XLO Test CD is actually on Amazon, $19.99 + free shipping. 
If you really wanna have fun. buy some actually accurate speakers from Magnepan that only reproduce what you send them and set those up in a given room.

Cheers,

Richard
I prefer not to buy anything from Amazon.  I ordered the XLO Test CD from Elusive Disc for $23.79 (including shipping).  They were in stock for a minute, looks like they're out again.  
I agree with richopp, but recognize that placement is probably more important to Maggies than most other speakers because of the fantastic imaging and sound stage they produce. When you get Maggies set up properly, you'll have an "so that's what I've been missing" kind of moment.
Note too that moving some speakers closer together can improve the imaging and soundstage which can seem counter-intuitive.
Geoffkait, $19.99 for the XLO Test CD is even better yet. Thanks.

Richopp and winnardt, your implication there are better and more accurate speakers than my Magico A3's is dastardly indeed.

Big_greg, since it was reported yesterday Amazon's Jeff Bezos just bought the most expensive home in all of California, he surely requires our full support. 

Mike




I received at Christmas a laser tape measure that measures to within a sixteenth of an inch. My speakers are now so locked in place with accuracy that it was a epiphany .
The laser method is not nearly as good as the XLO Test CD method. How do I know? Because the XLO Test CD will find the NEW absolute best speaker locations after adding room acoustics devices or other tweaks to the room. Whereas the laser method cannot account for new additions to the system or system tweaks. In fact the laser method doesn’t ever account for room treatment or tweaks. Hel-ooo! It’s not (rpt not) a static situation with the speaker locations. You do NOT want your speakers locked in place.
geoffkait

Thanks for the XLO test cd...I already look for it one year ago and forgot it....I try it seriously today...

Very interesting test....The 4 phase sections are very useful....


It seems my speakers are quite good and rightly located....


Before this test I guessed my system parts were in phase but it was only my impressions...Now at least I know that they are by testing.... Thanks with a smile from the past... :)
I went to Soundings in Denver and they demoed master setting speakers.  The sound is very noticeable.  What's nice is you don't have to sit in the sweet spot, which is nice when you have guests over to listen to music and cocktails.  I moved my speakers away from the wall and toed then in perfectly and that made a huge difference.  Adding a pair of REL S3 SHO subwoofers also improved the bass extension.  
I measured the distance from the back wall and side walls to measure exactly the same and then pointed the toe in to reach my listening position.  This instantly changed things.  I noticed my mid range and tweeters really settled down.
Yes skyscraper you are correct. With most modern studio recordings the image is based on what the mastering engineer thinks everyone wants to hear by virtue of his own ability to mix correctly and the quality of the system he is using to do this, all of which is questionable. Live recordings can be much more useful in evaluating a system. We all have our favorite records when it comes to imaging. We also know how favorite studio recordings image and know what to expect if a system is set up correctly.
As far as image size is concerned it depends on the type of speaker. Dynamic speakers create a small sound stage as if you are sitting in the back. Linear Arrays or Line source speaker throw a larger stage as if you are sitting up front. There are advocates of both types. A good system is capable of imaging beyond the speakers with the right recording. 
Using an out of phase signal to set up speakers seems a bit odd to me but hey, what do I know. I use a computer, a microphone and an impulse testing program to adjust the speakers in time, phase and frequency response. This does not negate the use of appropriate acoustic treatments and intelligent speaker location. I adhere to the symmetry concept and designed my media room accordingly. But, having measured quite a few speakers this does not guarantee the best imaging or symmetrical performance. Even the best manufacturers are not capable of making two speakers perform exactly the same. There are always some differences in frequency response. This is were a room control system comes into play. It can make both channels virtually identical which results in the best imaging.  
Even the best manufacturers are not capable of making two speakers perform exactly the same. There are always some differences in frequency response. This is were a room control system comes into play. It can make both channels virtually identical which results in the best imaging.  
Thanks very astute observation.... My best mijostyn