Long wall or short wall

Right now I have a pair of Aerial 10T's positioned on the short wall of my listening room. (the room is approx. 16' x 22') I read alot that people actually place their speakers on the long wall. Which is better and why? I am thinking of selling them to buy a pair of Vandersteen 5A's. Would the same apply?
Generally, sonics stand a better chance if speaker placement is on the short wall. There can be acceptions as I believe the Dunlavy SC-IV's were purported to be better on the long wall.

I believe the primary reason is to minimize room reflections from the back wall is perhaps the primary reason. In addition, I believe that the narrower side walls may help ensure sound travel from front to back.

I also own a pair of 10T's. But I've never tried them on the long wall simply because my rooms have only been around 12.5 to 13.5 ft in width and thus not allowing for much space behind the listening chair and the back wall.

As for selling the 10T's for a pair of Vm5A's. Do you even have to ask?

The 10T's are an excellent speaker top to bottom. I've never listened to them, but the possibilities of what the Vm5A's can do sound just too overwhelming to pass up.

I can't add much more to what Stehno has posted except to say that if you don't have decor restraints try them on the long wall. I have moved mine around several times and I do find that I like the sound better on what would be the short wall. My room is 15' x 30' with a 6'x15' jog that makes the room an ell. This gives me 21' along the "short" wall. The speakers are 7' apart and 3' off the back wall and I listen at around 8'.

I really like my 10t's, but Stenho has peeked my curiosity about the Vandy's. I'll have to find someplace close by to hear them
Thanks for the confirmation, Dan_ed. For speaker placement, might I suggest you try applying the Allision rule?

All measurements are taken from the front center woofer driver.

The Allison rule basically states that the distances from the woofer to the floor, woofer to the side wall, and woofer to the back wall should be as different as possible. To accomplish this, one would apply the following equation:

Middle distance squared = shortest distance multiplied by longest distance.

Implementing this rule along with toed-in speakers so the tweeters and midranges are pointed directly at the listener's ear could be an excellent starting point toward obtaining pinpoint imaging and 3-d soundstaging. And perhaps even the ending point.

For example, in my case, the woofer front center is:

o 3.5ft from side wall.
o 2.0ft from floor.
o 6.0ft from back wall.

3.5 squared = 12.5
2.0 x 6.0 = 12.0

12.5 is pert near equal to 12.0

My ears are now about 6ft from the mid-range/tweeter heads so I am definitely listening more in the nearfield.

I mentioned this to a buddy who owns Magnaplanar 3.6's (a bit harder to measure). He wrote back stating that he was no longer able to get to sleep at night because the new placement transformed his system's sonics.

Long wall placement has a LOT of advantages so long as you can maintain a decent distance between you / the speakers / back wall. Here's the first and primary reason why this is true.

When you have your speakers placed on the short wall, nothing you can do can increase the distance from the speaker to the side wall. Since there is a short path to the side wall from the speaker, you end up with more reflections coming back to you at a higher intensity that are closer in arrival time to that of the primary wave. Do you want to fathom a guess as to what this does to frequency response and the soundstage / imaging ?

Placing the speakers further from the side wall, you have a longer path to the point of reflection. Not only have the intensity of these signals been reduced, but they are now at a much softer angle. In effect, the reflections are reduced in quantity, intensity and less concentrated towards your seated listening position. On top of this, the arrival times from these reflections are spread much further apart from the primary signals that you've heard, minimizing their effects.

If you really want to get into it, short wall / long wall placements require different types of room treatments in terms of diffraction and / or absorption. To take that a step further and really get into specifics, this will vary according to the radiation pattern of the speakers too. This is why, and i've stated this MANY, MANY times, there are no "universal formulas" that work when it comes to the room acoustics / speaker placement for an individual room / installation. The thing that comes closest in terms of "universal recommendations for speaker placement" is the program called "Computer Aided Room Acoustics" aka " CARA", but even that is only as good as the specific data that you program into into it. Sean

PS... I've been an advocate of long wall placement for quite some time, long before i understood room acoustics. I followed what my ears told me and theories that i learned later verified what i was hearing. As a side note, long wall placement is not as critical with smaller speakers, especially those that have acoustic treatments on the baffle.
On the long wall, but the front of the woofer is at 1/2 the distance into the room. i.e. you woofer would be at 8'
Place each 5.5ft from the side walls.
Locate your seat AT the rear wall, at mid-point (11ft)
You'll have to play with the toe-in to see what sounds best...start with the drivers pointing slightly behind each year and adjust from there.
LEAN forward and BACKWARD from your seating position and notice the difference in the imaging and bass.
Adjust to taste!
This takes the side wall reflections pretty much out of the equation and also being on the rear wall (boundary) will smooth out the bass.
Give it a try while you are playing with some of the other configurations.
Anybody else ever used this config? Comments if so?
Happy Listening!
I agree with Sean's comments on Cara. For the price I have found it to be a very useful tool. I do have limitations with placement of speakers in my listening room due to a pool table at one end of the room. There are still many choices left for me and I have explored each with Cara and found that for each location Cara did find the best starting point placement for each speaker. Usually a staggard placement I would never have though of. Just to echo Sean's comments, Cara is a very good mathematical modeling tool. But all model goes-outs are subject to the goes-ins.

All of that being said, Cara can't listen for you. I have found that in my room a more conventional setup has worked best so far. I believe it is because of the 7' from each side wall to each speaker and also because of the softening of the 1st reflecting point waves.

I guess what I am saying is that long wall and short wall are relative terms when you take into account the magnitude of each measurement. For instance, in my case it could be said that I listen on the short wall but the width of this short wall allows me to reap the same benefits as long wall listeners.

And don't discount the imaging capabilities of the 10t's. They do require alot of power. I'm feeding mine 300wpc and have been advised by some that they need 400+ to really sing.
Audio Physics is also a big proponent of long wall placement. I had my Virgo's placed this way years ago. Now I have my Watt/Puppy's in pretty much the same config. Check out my pics in systems.

FYI: http://www.audiophysic.de/info/aufstellung/e_index.html
I have always used 'short wall' setups in the different rooms I had, but I have no philisophical problems with the other setup.

I have the CARA CD too. Rives audio has some helpful setup info at their website. Check out http://www.rivesaudio.com if you want to try it.

I do disagree with the suggestion of pulling the speaker 1/2 way out into the room. I can't imagine a speaker or a room in which this would be a rational solution.

If you can do it, play with placement and see what you think.
Give it a try. This config pretty much takes the "room" out of the equation. I used it in a BAD room config (15' x 15' x 8') and NO room treatment. Nothing on the walls and a rug partly covering the hardwood floor. (this was just a temporary setup)
The imaging was exceptional and the soundstage was excellent. The stage would have been better if I'd had a LONGER wall than 15'. Give it a try.....it'll surprise you.
Happy Listening.