Where do you put the measurement microphone when you want to
phase align two mains and a center sub? Where is the best place for maximum
results and most even coverage? I got an email from Bastian last week
who says, I'm a fan of using center subs, awesome, but with mono subs where is the
point of optimization? I thought I knew the answer this question. Then I
realized, I don't really know. So I posted on Facebook and a lot of people said, you
have to align at FOH so I'm using this microphone to signify FOH
You have to align at FOH because the mixer, the person
mixing the show, operating the show, needs to hear the best right it's their job to
do the balancing so they need to hear everything in phase. That's where you
should set it and that's what we call a monarchy, right? It's great for him, maybe
not so great for everyone else, depending on where FOH is. Then I took Bob
McCarthy's book and he says, use the OnAxL location in this example that's
similar and because that prevents three sources from sinking at the center
what he's talking about is that here in this design we've got these three
speakers and so if I align in the center I have one two three sources getting the
maximum level here and so as soon as we move left or right that is all going to
fall apart pretty quickly and I think I have an
example here maybe
yeah so it might look something like this so all down the middle
we've got alignment and then as soon as you start moving to the left to the
right it falls apart pretty quickly
okay and Bob McCarthy is suggesting a line with on axis a over here so that
would be B this microphone here and I believe I have a prediction of that as
well okay and that gives you a little bit more even results right still not
great everywhere but more of a democracy right it's good over here over here
maybe not so good right here but more spread out and also the errors are
symmetrical but Merlyn gave a great answer and he just wrote a great article
about it here on his blog where it's a time aligned the sinner sub and he has
this great diagram that describes it and what he says is to draw a line from the
main to the sub draw a line is perpendicular to it and then at the head
height at front-of-house that's where you should place your measurement
microphone where your head aligns with this perpendicular line okay so I
realized this diagram can be a little hard to see
so if map will not crash then I will show you yes it didn't crash okay so
here's the same thing but now we're at the back of the audience looking at the
sound system so here's our two mains and here's our sub theoretically so what am
I going to do let's draw the lines that Merlin has suggested so I'll draw a line
from the main to the sub then I'll draw a line that's perpendicular with that
line now where do I place this one well I need to bisect this line so it is
seven-point 18 meters so I'll divide 7.18 by two to get three point five nine
see halfway with it now I can make those two intersect okay now let's take my
about my head height and we'll make that line intersect oh okay so now we can see
horizontally where we should place the microphone and it is at six point three
five meters right so hopefully it won't crash again okay close let's get rid of
these let's put in some lines you can see what this looks like so here's the
center that's the first place we were talking about here's on Act's that's the
second place we were talking about now what if we tried a third microphone and
we put it at six point three five now we're not going to see a huge difference
because I already did a prediction at on XA and in this case it's pretty close to
on XA but this is what Merlin is suggesting and I run a few experiments
and it looks like it's really good so the next time I'm doing in alignment I
think that's what I'm gonna try so again in this particular example Merlin's
suggestion is really close to on XA but obviously in other ones with different
spacing different height it could be different so I would urge you to take a
look at Merlin where do they go take a look at Merlin's article read through
that and if you have any suggestions questions about how to implement this
let me know thanks