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

If you’re gonna read a book then Robert Harley’s Complete Guide to High End Audio is a far better place to start. Its not that the other one is bad, its just I find understanding concepts works a whole lot better in the long run than memorizing platitudes. The difference is my way you can actually build a music system and not just type word salad.

Like fibbo. Yeah Fibonacci, you looked it up. Did you find anything useful? Did the word salad typer have anything useful to say? No. Word salad. 

Let me explain why it matters, so you will understand, and be better able to position speakers and do all the other stuff that matters.

Sound travels in waves of different wavelengths. Which in a room is a problem, because sound keeps hitting the walls and bouncing back. Which if this happens with short frequencies like treble no problem we can disperse it or absorb it pretty easy. Because the wavelengths are short the stuff that will diffuse or absorb can be small. No problem.

Lower down though, the wavelength can be longer than the room. The wave hits the wall, bounces back, reinforces itself. You get what is called a room mode. Where this happens the bass will be really loud. But it can also cancel. Where this happens the bass can be almost totally cancelled to nothing.

Got it? So far we’re just talking like its one way. But its three ways- length, width, and height. So what’s the worst room? A cube. 12x12x12 or whatever. Doesn’t matter. 20x20x20. Whatever. All those duplicate dimensions result in the same mode and the same null and the only thing different is the frequency.

Knowing the physics you can sit down with a piece of paper and map or graph out the various length, width, and height room modes for any given room. Then plot them out and see. And oh, guess what? There’s actually a chapter in Harley’s book on this.

So anyway, you do this enough times for enough rooms and eventually some smart alek says hey the room with the smoothest most spread out modes follows this fibonacci sequence where the dimensions are fibonacci ratios of each other. Only nobody ever gonna build a room like that, because its like fractions of an inch difference, you just want to avoid stuff like 8x16x24 which you would know because I just explained and now you know all those are multiples of each other.

You see, I hope, the difference between information and word salad?

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.

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.

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.