Right placement for monitors to measure acoustic

[laronermma]

Before I organize the space in my control room should I place the monitors in some special way?
Now the monitors are placed according to the following rule: http://www.cardas.com/content.php?area= ... Room+Setup, but while searching the internet I haven't found even one person to rely on the rule. That is why I am asking for help and any kind of helpful advices in what way the monitors should be placed while making the measurements.
For measurements I will use signal patch Adam P33A, Behringer ECM 8000, TC konnekt 48, Room EQ Wizzard

[Soundman2020]

Whoever wrote that seems to be more than just a little confused about modes (not nodes: different things), and about room ratios! To start with, there is no such thing as a "golden ratio", and even if their were it would be relevant to the room, not to the placing of speakers within the room. While positioning speakers carefully can help prevent them from exciting room modes, you might find that the positions would be rather curious! But you cannot eliminate room modes by placing speakers at certain locations: Any given room has hundreds of modes in the low end (below 300 Hz), and your speakers will always excite some of them.

It also looks like the author of that page read about Wes Lachot's 38% "rule" somewhere, then completely misunderstood it and put his speakers where his head should be! His diagram on that page you link to doesn't even show the listening position, which is critical to speaker placement, and also doesn't show the speaker toe-in angle, which is just as critical.

I'm not surprised that you can't find any other references to it as being a good way to set up speakers: I doubt anyone on this forum would recommend setting up a room as shown on that diagram.

On another page of that web-site, he defines his "Golden Ratio" as being 10" x 16" x 26" feet (which isn't a ratio anyway: it's a set of dimensions). But if you plug in those numbers to any of the common room ratio calculators, the results are not too good at all! The Bonello graphs shows not one, not two, but THREE flat spots, and one of them is even a dip. So how can that be a good ratio? In fact, it comes up as being similar to number 20 on Eric Desart's list of ratios, classified as "Origin unknown: Resembles Id. 19", so there are at least 19 better ratios than this so-called "golden" one! (Number 19 is also classified as "Origin unknown").

With this supposed "Golden Ratio", any room mode calculator shows that there are multiple overlapping modes (Eg. 56.0 Hz (1,2,0 Tangential) and 56.5 Hz (0,0,1 Axial), as well as 70.1 Hz. (1,1,1 Oblique) and 70.6 Hz. (2,0,0 Axial)), so there will be some major issues with those frequencies, totally independent of speaker placement. There are also several isolated modes, with more than half an octave of empty space between the first pair and also between the second pair! The mode distribution for that "ratio" is not even at all. I would not build a room like that.

The best thing you can do if you are worried about room modes, is to build a room that has a know good ratio (not "The Golden Ratio", since there is no such thing: just a good one. Anyone one of te 19 that are known to be better than this one!), then soffit mount the speakers in the front wall, and arrange your speakers and listening position in the commonly accepted manner: at the vertices of an equilateral triangle, modified as recommended on this forum with the intersection point a few inches behind your head, not inside your head. The speakers should be angled to point directly at your ears, since on-axis is where the speaker response is flattest, and where it is always measured.


- Stuart -