I never really thought about it when I unpacked my NS10Ms some 20 years ago.  I put them up at ear level with the Text graphic oriented in the horizontal position like it seemed logical to do.  The biggest question was whether to have the tweeters on the outside or the inside and most of the studio pics I saw had them on the outside.  So that's the way it's been since then.
 
But this week I was looking at some candidates for mid field speakers so that folks wanting to hear a mix in the small couch behind me might have a bigger sweet spot.  So I ran into articles and discussions about how speakers should be oriented.
 
Part of the discussion involved the NS10 and NS10m and how they came to be oriented horizontally and the reason that position came about.  I even found a post from a guy who had his vertically with the tweeters on the bottom.  Lately, I've been questioning everything that I do and made a habit of so, what the heck, I had a free afternoon and I started moving speakers around.
 
First thing I immediately noticed that the vertical orientation was more focused and "lined up."  The sweet spot was definitely bigger in the sitting position.  I kept spinning them 90 degrees and listening and every time, the vertical orientation sounded better.  And like the one odd ball guy, I ended up with the tweeters down because that aligned with my ears better.  Even the bass response was tighter in that position.  So for now, I'm leaving them upside down.  

Awesome post!!!
 
 
 
 
 
 
 
 
 
 
 
 
...bapu should read this.

The reason to have the tweeters on the out side is for time alignment.  Since the woofer is deeper in the box the tweeter naturally has an advantage by being closer to the listener by an inch or two.  To compensate it is traditional to place the tweeter further away.  Unfortunately this means a chance of missing the sweet spot entirely when sitting too close.  
 
It definitely sounds better to have the tweeter pointing directly at your ears, though that may give you a false sense of what the sound truly is.  The lower frequencies could be delayed and slightly out of phase with the highs.  Just something to be careful of when situating them. 
 
I definitely think it is better to have the tweeter vertical at any rate.  The stereo image can become out of focus with a two-way horizontal alignment, especially in the near field.  

H

The thing that I noticed was that I could hear the tweeter separately from the woofer and just moving my head forward and back brought this out.  Didn't take much movement at all. 
 
Most folks tend to agree that the horizontal positioning was not intended at first.  In fact, the logo was 90 degrees from it's current orientation on the original release because they were intended as bookshelf speakers.  The horizontal position came from a need to not block the main studio speakers which is something that I am having to deal with now.  I've got a pair of soffit mounted JBL 4312s behind them.  That's not a major problem for me because I was looking for a replacement for them when I started reading up on tweeter/woofer orientation.

Mod...The NS10s I've listened thru, I've never really liked, but I've used some that were as far away as your 4312's are.  That was terrible, actually.  I have some 4311 that I've used for years and years, and really liked them.  Then, this last winter I got some Yamana HS80m on an impulse buy because I got them used for $300/pr.  I don't think they're really much like the NS10, as much as some people say they are. I figured, they'd make a good alternative speaker along with my old Auratones.  When I first listened thru them, I was blown away and have since just pulled my 4311 out of service.  I've tried flipping my Yamaha's in different orientations, but on the side with tweets out ended up being my favorite.  I'll have to visit vertical again, as that's been recommended to me over and over again.
Mod....looking at your studio pics, I'd think your 4312 would be blocked a tad, firing into the back of your desk and NS10s.  When they're cranked a bit, I suppose that wouldn't really matter so much, and that's where my 4311 excel actually as well... up an amount louder in the 100+dB range at the listening spot.  Low volume, the Fletcher Munson seems to really take affect and they sound thin and *honky* now compared to my little, inexpensive Yamahas, which sound pretty much the same at any volume.  But especially good at below 90dB.
I've been told to lower them as well, but they are pretty much at ear level.

Also...Hey Mod... I'd be interested in your take someday, if you ever listened to the current crop of Yamahas... like the HS8.   The inexpensive JBL ($250 8" version- LSR 308) are pretty much in the same catagory too.  You might be as surprised as I was with these *newer* speakers...even with their low cost.
 
On an aside...I listened to some Focal twinB fairly recently... infact the guy I got my HS80m upgraded to them...  And although they were very nice, I didn't see them as $2500+ nicer.  I thought the HS80m hung right in there, as a surprise.
 

The cones of the speakers are the same difference away as in the tweeter and woofer; it is called being in Phase!
The cones of the woofer if the coils do not have proper suspension can sag, and go out of alignment. That is what different speakers do when not made properly or stiff enough to hold the suspensions of the cones and coils in place.
That is why better speakers sound better over the long run, or speakers made to be that way.
The area of dispersal of the frequencies create the image of the sound and the speakers should be made to specific tolerances to accommodate aging and alignment of the speakers. If sounding too bad or placing those speakers vertically or horizontally then the speakers just were not made good enough.
 
Buy a newer pair now knowing that companies scrimp on features like that when they made the speakers.
Sorry, but I just trust JBL if the speakers were good enough from them in the first place.
I doubt those cheaper monitors they built even though good wide dispersion will last all that long in the end.
??
It is a throw-away world it seems. Last awhile and continue to use it like it is, or invest in a newer set of speakers because somewhere in the brain you knew that it had happened and you finally realized that part of cabinet and speaker making.
Spend more money or be satisfied with what you still have, I suppose.
End of speel!
End of feedback!
End of distortion.
The end.
 

spacealf...what are actually saying?  Are you saying the newer breed of inexpensive speakers are just disposable pieces of garbage...or??  That JBL's newer cheapies sets are just that...and don't compare to their older, but upper end stuff....not that the 43XX series was *upper end*.  Just popular like the NS10 became to be.

Just that they may not last as long as in usually the more you pay the more you get, but there is a break point where the expense becomes so much more for the increase in quality that most people probably will not buy it.
Afterall I would think the Event Opals would last longer but they are 10 times the cost (for one speaker than the JBL speakers that just came out for two speakers). The real JBL Monitors are $20,000 dollars, and are huge and very heavy and also handle a lot more wattage and are different than the speakers instruments are played through in the sense of transient response which stereo monitor speakers are supposed to be better at.
 
http://www.sweetwater.com/store/detail/M2System/
They come with two Crown Power Amps.
 I just do not need 1200 watts of amp and speakers though.
 
 But on speaker design and cabinet design:
"Our ear is not an ideal instrument of sound perception and sound waves do not propagate through space ideally." (from link)
http://www.audioholics.co...dspeakers-buying-guide
http://www.buyingloudspea...peaker%20Enclosure.htm
http://www.duncanamps.com..hnical/speaker_cab.html

The current concept of loudspeaker was created in 1898 by Oliver Lodge, an English scientist.
http://en.wikipedia.org/wiki/Oliver_Lodge

http://www.edinformatics....entors/loudspeaker.htm

Plasma speaker
http://en.wikipedia.org/w.i/Plasma_arc_loudspeaker

The Art of Speaker Design
http://www.nutshellhifi.c...y/speaker-design1.html

Plasma Ion Tweeter
http://www.enjoythemusic....002/acapellavoilin.htm


I think the Yamaha speakers are all acoustic suspension speakers.
But there is the bass reflex enclosure, the horn enclosure, and the folded horn enclosure (for bass frequencies) and whatever else is been built as a speaker and speaker cabinet design.