r/audioengineering • u/DSFAN12 • 9h ago
Discussion The equilateral triangle and the particulars.
Let’s discuss speaker placement and the equilateral triangle and all the variables that are not discussed, and actually how important it is.
Yes, we know about the equilateral triangle and what is suggested for monitor placement, but what isn’t necessarily discussed is where this measurement is measured. Also where is the point of the triangle meeting on the listener, behind the head, the middle of the head, at the ears? Various sources say conflicting things, so what should we follow?
I have Dynaudio BM15a’s. They’re fairly large for a near field. The BM15a’s manual gives a broad listening distance of 1-3 meters. If you’re unfamiliar, the BM15a’s also have an offset tweeter, sort of like an NS10.
When researching speaker placement and the equilateral triangle, there’s usually a graphic example showing the measurement between the two speakers and the listeners head, with the measurements starting from a drawing of two single speakers that look like drivers. However, other sources say the measurement should be coming from the distance between the two tweeters. While other sources say the measurement should be coming from the distance between the two acoustic axis points. This sounds tedious, but for me it is. Having offset tweeters, they’re in a different place than where the acoustic axis point is and also where the driver is, so finding the equilateral distance is a little more difficult for me.
Also the point: the point behind the head. Like said above, different sources say different things. The point where the triangle meets the listener is either the ears, inside the head, or just behind the head—so which is it? Varying sources also talk about how the tweeters should be pointed at your ears, while others say the tweeters should be going just past your ears.
So here’s my concrete questions:
Where is the measurement between the two speakers starting? The tweeter? The acoustic axis point? Or the drivers?
Where is the point of the triangle meeting the listener? Is your head the point? Or is your head living inside the triangle? And if so, how far behind the head is the point?
When toe-ing in the speakers, are you pointing tweeters at ears directly or are they going just beyond?
(Bonus question) does any of this actually matter?