Anotherspeaker placement question (distance measurements)

immathewj

I just added speaker placement measurements to my Virtual system photos 

which also has the room measurements .  The manufacturer of my speakers came

with basic recommendations but then one has to deal with the room

measurement .  Start with an equilateral triangle and let your ears do the walking.  

As far as stuff between the speakers. In general, yes it usually screws up the imaging. It is unfortunately, like everything in audio, somewhat dependent. I had apogee ribbon speakers for many years… for some reason the equipment rack did not make much of a difference if any. But all the other speakers I have had, definitely matters. Not subtle at all.

First of all, typically, to develop the capabilities of speakers soundstaging you first have to get the toe-in, rear wall distance, and rear dampening correct… then hopefully your soundstage will go beyond your speakers, left and right. Then you work on depth.
 

Typically, an undampened rear wall, will either cause confusion in the imaging or present the rear limit the of the sound stage. If you add dampening… I have always liked thick wool oriental carpets. The dampening changes from almost none (a sheet), a bit (blanket), to good… a thick, heavy, tightly woven wool rug… like mine (hold your breath… these things are expensive… hence people use other stuff).

Anyway, so in my current room, the sound stage extended from my speakers (front) to the wall without the carpet (wall is plasterboard, 2x4s, with concrete and solid earth behind that ((yes… I am really lucky)) ), about 4.5’. Adding the carpet.. the soundstage goes into the wall two or more feet. Somewhat recording dependent of course. Put my audio rack there… and there is a gaping hole where the equipment rack is. Not a subtle thing. A hole… no sound in there. I am sure I could bring in a neophyte and point out all the characteristics of my system, and point out the hole and they would be able to “not hear it”, easily during the first session.

All of this is contingent on doing the work to get your system set up correctly. It is also dependent on your speakers and associated equipment, but probably less so than many think. I am pretty sure you could put a system together for $2K speakers and $1K components and craft outstanding imaging… probably less. Most “decent” equipment is capable of great things in the right hands. One must be patient and listen. 

@bigtwin  , I cannot and will not try to speak for gdhprentice, and I hope he does offer his explanation so I can learn if what I think is correct  Anyway,  I remember back in the 90's when I had a prescription to Stereophile, I had read in one of their articles that keeping the area between & behind the speakers clean made for better  imaging (I assume center imaging) & I thought I remember reading that it could have an effect on the soundstage.

But with all that typed, a lot of what I thought I remembered learning from Stereophile gets routinely debunked on the forums.  Meaning maybe I misinterpreted what I was reading or maybe there is more than one way to skin a cat & the way they wrote about it in Stereophile was the wrong method.

Anyway, hopefully @ghdprentice  will weigh in on that.   

@ghdprentice  Now sure I understand your insistance for no gear between speakers.  Explain please?

😊

@ghdprentice , oh, don’t get me wrong, it wouldn’t be jealousy (well, maybe a little bit of envy, if I was totally honest), but I think it would be hard to listen to mine after hearing a system on that level.

I remember back in ’94 or so when I started down this destructive path, my wife & I went to a brick & mortar "hi-fi" store because at the time I was wanting to move up to a Carver CDP that featured a 6DJ8 in the DAC. (I certainly "progressed" since those innocent days.) Anyway, after I listened to some stuff in one of their listening rooms & had met a couple of salesmen, one young guy (& I was young back then also, but he was younger) was telling me about his Silver 9s (or Silver 7s, I cannot remember which) and also about Winston, another salesman I had met, who had to get rid of all his stuff and wouldn’t replace it with "affordable" because his previous gear had ruined for something less. I can maybe see that.

Anyway, there is a lot wrong in my room, but one thing I’ve got right is no gear between the speakers or on the back wall.

However, as far as my dogs go, I give them run of most of the house, but I don’t trust them (one in particular) a whole lot, & therefore, they don’t go in The Room.

OP,

Thank you for your kind words.

I can’t tell you how much better my system sounds with the careful tweaking I have done (something a system at any level can benefit from). The room tweaks… getting the equipment racks from in between the speakers. Deadening the wall behind, speaker placement… etc. have improved the sound quality.

You noticed the room… well that was luck. The best room I have ever heard. My audio guy as well… and he has been installing $100K+ systems for over 20 years… many in dedicated, purpose built rooms. As I said luck there.

BTW, in a previous house, with ribbon speakers using a 1’ wide by 4’ strip of thick wool carpeting made a huge difference in imaging. While a much more modest system, I would have put it up against much more expensive systems. It is not all about cost… tremendous advantage can be gained by effort. 

But, your system can be every bit as rewarding to you. I have had many systems, and listened to dozens “better than mine”. They helped me shape the direction I took in constructing mine. Listening to great systems is a great way to learn. Surprisingly, often jealousy does not ensue.

My dogs enjoy music and are why my audio seat is a love seat… one place for me, and one for the dogs. I also love it when they take up an attractive pose in front of the system.

@ghdprentice  , I went to your page & looked---awesome room and system!  Way, way, way out of my league.   I hope you still have the dog?  I did a quick search on your speakers and I may be being materialistic, but I believe that to a large extent you get what you pay for.  I believe you when you say that they are wonderful speakers.

It would probably be a bad idea for me to hear a system like that.  Most nights I am not hearing my room or my speakers--I am hearing the music & I think things sound fantastic, but fantastic is a relative term and hearing gear of that caliber would probably be the ruination of my own experience.

In the mean time I'll keep working with what I have and after looking at yours I think I am going to experiment with throw rugs and blankets and if I get some sort of positive results I'll look into room treatments on a higher level.

Rock on!

Let’s address the elephant in the room — what are your room dimensions and on what wall are your speakers situated?  Not sure why this critical info has to be a national secret.  Sheesh. 

@soix 

Probably because everyone will tell me to give up & quit bother trying?

Okay, from the bare wall I am using to place the speakers along to the integrated book cases(s) that cover the back wall is 8'4.  To the left of that is a even boundary, that I have been referring to as a wall for the purposes of measuring, is a gun safe and a file cabinet, they are about 5' high, and they double as an equipment stand for my amp & CDP; above them & attached to the real wall are two shelves which hold my preamp and the power supply for the preamp and several pieces of gear that are being unused at the present--therefore there is no gear behind or between my speakers.  From that boundary to the righthand boundary is about 8'.  This boundary is a file cabinet and book cases filled with books and CDs which extend up to a shelf near the ceiling also filled with books.

Using the formula @bigtwin  provided I started with slightly less than 27" from 'front baffle' to wall and 22.25" from center of tweeter to side boundary.  These are B&W 805s.  I tweaked them to 27" & 22".  Without getting up & measuring, I believe center of tweeter to center of tweeter is 47" and to achieve a ear equilateral triangle, I have about 21" behind my ears to the book case laden rear wall.

As I have previously typed, in the past I had height and a lateral sound stage that extended beyond it's boundaries.  There was/is a less clearly defined sound stage from front plane to rear wall, but none the less, a sound stage.  I lived with what I had before, trying occasional placement tweaks, but it was a couple of recent threads here & in amps/preamps that got me going on this recent endeavor to see if I could achieve more in this small flawed space.  However, with the lights off & my eyes closed, my speakers to disappear. 

So, it is really true. Formula are simply a starting point. For me, I did my movements over a year. I plunked them in the prescribed place. And listened for a couple months (they are really awesome speakers). I realized they were capable of disappearing, but were not and the soundstage was restricted. So, I toed them out some. Listened for a couple weeks. No question… better. Moved again. Better. Some folks move, listen, move, listen… in a day. I find that confusing. I prefer listening to the music and wholisticly appraising the change.

Thank you, @ghdprentice  , I am keeping this in mind as I work on this.  You are more patient than I am.  I am often lazy, but less often patient.  I am using the formula that bigtwin provided as a place to start from this time around.  In the past it was always how far do I think I can get away (get away from a sonic perspective, not the perspective as 'am I allowed to') pull them out & spread them a part.  This is about as scientific as I have ever got with this aspect of the hobby. 

Let’s address the elephant in the room — what are your room dimensions and on what wall are your speakers situated?  Not sure why this critical info has to be a national secret.  Sheesh. 

"I ain’t ever satisfied," Steve Earle wrote a song by that title.

@bigtwin , with the adjustable dimensions from the formula that I used to achieve 32.75 (or quite close) I did some listening. These dimensions put my speakers closer to the rear wall and further from the side boundaries,and since being further from the side boundaries moved them closer together, I had to move my listening position in significantly which, needless to say, increased the space between me and the book shelf covering the back wall.

"Comparisons are odious." I don’t know about that, but I hate doing them. It seems like when I try, I am never positive about what I heard the last time that I am attempting to compare to.

Anyway, what I feel that I might have noted (how’s that for being definitive?) is that the lateral sound stage is not as dramatic now; it still extends beyond the the speakers, but it doesn’t seem like (maybe) it is as far beyond the speakers. I always did & still do have great center imaging. However, I do think that (maybe) I am hearing more of a fullness from the forward plane of my soundstage to the back of my sound stage. However, the imaging within fore to aft is not as precise & revealing as from left to right & it never was. I don’t feel that height of the sound stage was affected, or if so, not by much.

One thing for sure, I previously made some comments about needing to turn off the lights & close my eyes or it was like sticking a pin in the balloon of my soundstage, and now with the speakers closer together & me even closer to them it is twice as true.

I am thinking that it would be the speaker placement from the side boundaries that would affect the lateral soundstage the most?

Next time I evaluate I’ll tweak only that dimension a bit and see what happens.. Like maybe an inch. I am also thinking I’ll hang some wool blankets on the side boundaries and if that is an improvement I will seriously start considering some type of room treatment beyond that. I have been playing the same three SACDs every time I do this, and I’d kind of like to listen to something else, but I am afraid that would really screw up my ability to compare.

@bigtwin , mid range/woofer driver distance was a typo: 32.75 not 33.75.

Last night, after I finished typing, I got back in The Room & did some repositioning (but no listening as of yet).

                                   One thing I did determine, if I’ve got it correctly, with mid range/woofer driver distance being ’dimension C’ moving speaker out from rear wall means speakers also need to move in from side wall in order for the formula of: (BxB) divided by A = C (since in my case C, woofer/midrange distance is a fixed dimension).

So what that means (in a small area such as mine) is: limitations are placed on how far the speaker can move off the rear wall as when the speakers correspondingly move in from the sidewalls they get closer together. I would think that being too close together could not be lateral soundstage friendly(?) but I guess there is one way to find out.

My back wall is clean, meaning that there is nothing between the speakers and the wall.

What I am calling my sidewalls are not really walls, I should probably start referring to them as side boundaries, and that, unfortunately is not an option to play with, other than doing a 90 degree relocation with the speakers. The left boundary (I have been calling a wall for measurement purposes) is a gun safe and a file cabinet, this boundary is an even flat plane, about 5’ high (higher than the speakers) and doubles as my equipment rack. (Therefore, my electronics are all off to the left side and not between or behind the speakers.)

The right boundary which I have been referring to as a wall for the purposes of measurements is a relatively flat/even plane made up of a file cabinet (again about 5’ high) and book case with books and CDs going to the ceiling. (The wall behind the listening position is book case going to the ceiling.)

I am fully cognizant that this is way less than ideal, but in the past I have been able to reproduce a lateral soundstage that exceeds the boundaries, and plenty of height. Front to back has been filled, but I never got as much placement of detail from fore to aft as I do side to side.

I have recently been using about four well mastered.mixed SACDs for evaluating; they all have revealing imaging in various locations going on.

@immatthewj  I start with the triangle rule and kerp in mind it's not the law.  Many suggest trying to keep the distance between speakers not less than 75% of the distance to your chair. Once I have my chair set, I will stand behind the speaker and aim them to focus just behind my head.  Once again, it's what works for you.  All these rules are only guidance to help each room and system give max enjoyment.  Have fun with it.  

  @bigtwin  , (I will make a correction & report that my woofer is about 33.75 & the formula with the variations I was calculating with was giving me numbers very close to that) math was never a strong subject for me (I think that is why I have such troubles with electrical theory) but I sat down with a pen, paper & a calculater (I am still living in the 20th century) & went to work with my constant which, using the formula you provided, had to become C.  (I did say that this room hsa small amount of clean space to work with)  I started experimenting with BxB which is the dimension I feel I have the least flexibility with (side-wall-to-speaker x side-wall-to-speaker) and found a B that would work in my space and then I started adding inches and 1/2 inches to B and calculated 6 speaker placements that will fit in my allotted space. 

I am going to start with the numbers for the formula that will put the speakers 27" from the rear wall & go from there being fully cognizant that this formula is not etched in stone & if I cannot make it work, all I am out is my time & if I do discover the lost chord . . . hey, far out, man!

BUT:

the formula does not make any recommendations for listener's distance (I suppose ear to tweeter is what I should be measuring?) and I have been living with the preconceived notion of an equilateral triangle.  Is that where you would put your chair (to start) if you were using this formula to place speakers?

@immatthewj  Correct.  The shorest distance can be any of the three.  I think normally there is a Bass driver on the bottom and therefore that would most often be the shortest of the three.  Use the formula and the speakers can be in a variety of positions.  In the end, it's how they sound to you.  Cheers.

Thanks to all for responding.

@bigtwin  , I did read your response in the other "room size" thread.  Like the OP of that one, I am working with a small space.  When you posted this formula, I did not, at that time, work with any of your measurements.  I just went back to take a look to see how it would apply to me, and the center of my midrange driver (these are monitors on stands) is 33"  You stated that floor to center is usually the shortest (therefore 'A') but it doesn't have to be, correct? 

The key is you use something consistently, that is all. I always use the front plane and tweeter for toe in.   As you know, all the recommendations are only starting places. So, it only maters you use something consistently. 
 

As an example, the recommended starting toe in for my speakers is to cross the beams 18” behind my head in the listening position. In my room, they sound best…. by a large margin with zero toe in. None. 
 

So, it is really true. Formula are simply a starting point. For me, I did my movements over a year. I plunked them in the prescribed place. And listened for a couple months (they are really awesome speakers). I realized they were capable of disappearing, but were not and the soundstage was restricted. So, I toed them out some. Listened for a couple weeks. No question… better. Moved again. Better. Some folks move, listen, move, listen… in a day. I find that confusing. I prefer listening to the music and wholisticly appraising the change. 

I always use the center of the woofer.

That is; From side wall to center of the woofer and from the wall behind the speaker to the center of the woofer (at the front of the cabinet).

Same thing when measuring distance between speakers, from center to center of the woofers.

ozzy

There are some great calculations and theories for optimum placement available to us, but none of them address the variables that are unique to your room, so they aren't an absolute or one size fits all solution.  Use those theories and calculations as a starting point, but don't be afraid to experiment and find what's optimal for your room.  If it pleases you and works in your room, it not wrong. 😉

@immatthewj   Hope this helps.

Focal, who know something about speakers, uses a flexible equation to find the best speaker placement.

“Optimisation For perfectionists, here is a formula for optimal positioning: If A is the distance from the centre of the woofer to the nearest floor or wall, B is the distance to the next closest floor or wall, and C is the greatest distance (A < B < C), the equation B2 = AC defines the ideal loudspeaker position. • Example: If the centre of the woofer is 20” (50cm) away from the rear wall (A) and 24” (60cm) above the floor (B), then the side wall will be ideally 28” (72cm) away [C = B2 ⁄ A = 28” 

I found this a little confusing at first, but it became clear in short order.  There are three distances involved.  Floor to center of woofer, Side Wall to center of woofer and rear wall to canter of woofer.  The shortest distance is always “A”.  This is usually floor to center which is the only constant.  The next shortest distance is always “B”, and the longest distance is always “C”.  The distance “C” is always (B x B) divided by A. 

By example, if your floor to woofer is 24 inches, and you are 30 inches from the side wall, you would need to be 37.5 inches off the rear wall.  Find the numbers that work for your space and see how you like the sound.  

In a nutshell, Focal suggests there is no rule about distance from any wall as long as C = (B x B) / A

@newbee  , center of the driver then.  Thanks!

You can reduce the sidewall distance (from the center of the driver to the wall) somewhat by deadening the surface of the wall adjacent to the speaker and slightly forward of the front of the speaker. This in combination with some sharp toe in helps a great deal. However the benefit is mainly in the mid's and high's. The mid bass is more difficult to control and depending on the distance to the side wall might well give you a mid/upper bass boost. Re toe in, I point the axis of my speakers to my corresponding ear. You can get excellent results by crossing the speakers axis in front of your head. 

All done by ear for enduring results, lots of speaker movements and it takes a long (!!!!!!) time to get your final results. Oh, BTW, measurement are made from the walls to the drivers, not the box. 

Have fun. :-)