I wasn't sure were to post this. Moderators please put this threat where it should go.
 
I was sitting at my desk pondering re-arranging things and I got to thinking about how I placed my monitors. I placed them on their side and realized I put them in a triangle sweet spot position with the woofers facing my ears at ear level so the high frequencies are passing by the sides of my head.
The standard seems to be if you place your monitors in the vertical triangle sweet spot position the tweeters should be facing your ears at ear level. This means the bass frequencies are hitting your shoulder or thereabouts. If you place your monitors sideways in the triangle sweet spot position the tweeter should be facing your ears at ear level. This means the bass frequencies are hitting your face or each other in a criss cross manor.
I can understand the vertical position but not the sideways position. There can't be anything good having the bass frequencies smashing into each other. I would think placing the tweeters on the inside facing your ears at ear level would make more sense where the bass frequencies are passing on either side of your head which is the opposite of how mine are setup now. Since I'll be re-arranging I thought I'd ask about proper placement.
 

Funny I just read about this in either Sound on Sound, or a lynda video.  They said to avoid speakers on their side if you can because of the very reason you pointed out.  They said they see it in a lot of studios, but it's basically a nono.
 
 

First of all, I think folks fret too much about such things. You'll train your ears to whatever way the speakers are situated and oriented. 
 
That said, I prefer to have the tweeters at ear-level rather than having woofers aimed at them, simply because high frequencies are more directional and it's they that determine the "sweet spot". Low frequencies radiate outward in all directions, which is why you can put a subwoofer pretty much anywhere in the room. (Actually, you place them where resonances are least-problematic, but that might be anywhere in the room.)
 

Ha ha, new laptop...getting used to its touchpad, which seems to be calibrated for feather-light touch! Stuff's popping up all over the screen because merely placing my palm near the thing causes a click/Enter response...oh hell, I just downloaded SQLExpress twice!
 
 
 

there are rules.
 
they depend on the size/shape of your room.
 
a good starting point:
 
http://arqen.com/acoustic...tup-speaker-placement/

If they are true near fields monitors you do need to have the tweeters pointing at your ears. If on the other hand they are general purpose loud speakers it doesn't matter. 
 
You may ask why? Its all about the dispersion of near fields in that they have none. So to hear the highs that they put out well they shouldn't be off axis.  Regular loud speakers are designed to have a wide dispersion to fill a room. Near fields are not so designed.  They try to give an accurate frequency response on a narrow beam and somewhat close. They don't care about filling the room with balanced sound.  
 
Try this. Back off your speakers as its playing back. Walk from side to side. Being off axis as you past through the beam. You should hear a drop in the highs the further you go off axis. This can also happen with cheap regular speakers however, its not for the same reason. Its because the maker used low dispersion tweeters that are beamy to save money.  Near fields are beamy because they are close to the listener. Thus they need to be beamy. They should have much better transient response too. With high quality drivers (tweeters) the maker wants to put the money into making them sound best not fill the room. 
 
BTW low frequencies don't have this problem.  But you may run into standing waves that can null the lows at various spots in your room.  

The only reasons I've heard for placing monitors in the horizontal (landscape) position are 1) that certain models were designed to be used that way (and actually state that in the manual) or 2) it allows the producer to see over the top of them so they can see the musicians better. 
 
The later model of the NS-10 (the NS-10M Studio, after Yamaha identified a market for them in the studio) was clearly designed to be used horizontally because they stuck the logo on in that direction.
 
So this:
 

 
As opposed to this:
 

I have a pair of Adam A-5X's with a folded X-ART tweeter which is designed for horizontal distribution.
 
I have a pair of Neumann KH 120's with conventional tweeters, but with  a flare that is also intended to widen the sweet spot horizontally.
 
There are other nearfield monitors with this kind of design feature, so these are not optimal on their side.
 
sharke, is that NS-10 yours?!?

Orientation is especially relevant for ribbon tweeters such as those used by ADAM, as they do not have the same spread in both directions. Given that they're quite directional anyhow, orienting them incorrectly might well narrow the sweet spot. Other monitors, such as Genelecs, have ovoid-shaped waveguides designed to spread the signal on the horizontal plane, so the same principle applies to them, too.
 
Silk-dome tweeters are more omni-directional, so I wouldn't expect orientation to be a big deal for NS-10s. However, I do know that there were two variants of the NS-10 made, one meant to be horizontal and the other vertical. What they did differently for the horizontal model, I do not know. The tweeters look the same.

I use Equator D5's and the tweeter is in the center or the cone (coaxial design) with the bass port below. The are small enough that I would not put them on their sides. 
My old NS-10's were designed to sit on their sides and it did make a big difference when I changed their positions. 
It really depends on your room size and environment. 
Experiment!