Hi BRuggles

If someone needs to use toe in as a tweak that is a sign that something is wrong with the room/speaker interface or with the speakers construction.

michael green
MGA/RoomTune

I am a recording engineer, but maybe they will respond as well.

have a great evening

michael green
MGA/RoomTune

Hi BRuggles

Here's my view and this may show you how I come to my answers and suggustions.

I don't see the room and the speakers as being two seperate devices. I see them as co-dependants. The speaker puts the soundwaves in motion and the room pressure makes the sound.

here's some threads
http://tuneland.techno-zone.net/t200-understanding-acoustical-pressure-zones
http://tuneland.techno-zone.net/t247-acoustical-basics-for-audiophiles
http://tuneland.techno-zone.net/t222-don-t-kill-the-sound
http://tuneland.techno-zone.net/t80-what-is-sound

In short there are two camps of looking at sound. One is sound as straight lines and the other (the one I belong to) sound as spherical pressure. In the pressure camp, the picture painted is your ears and head are picking up on the pressure the room is giving you. If the system is setup correctly you will hear 360 soundstages and your ears will be in balance with the energy in motion. You hear in Stereo regardless of what is producing the sound and your ears and brain are designed for balancing the left and right pressures that come at you. So what I'm saying is your listening to 360 sound all the time and the right and left and center device sitting on your shoulders picks up and responds to pressure 24/7. Stereo playback is really pretty remarkable in concept but it's not really about straight line reflections as much as it is two sources feeding the room's pressure.

In the past people have made meassurement of how sound works out of straight lines as if there was no pressure build in the room. This is where all the angles and formulas came from on setups, but the truth is, these things don't exist in an enclosed space. To this day audio engineers are using old school formulas to come up with placements but I can tell you first hand that none of these make for accurate sound and propper soundstage sizes. People might make these formulas cause they are trying to explain something that is more complex in a simple way, but these formulas do not hold up in physics. So if you say I'm sitting in an equilateral triangle with my speakers and because of this, this is what I hear, this same formula done in any other room in the world will give different results. Room construction and environmental conditions dictate the sound of all rooms and no placement formulas can undo this.

As far as soundstages being messed up. They are messed up in most systems. Most stereo setups are producing maybe 10% of the content that is actually on the recording.

michael green
MGA/RoomTune

Depending on construction, mics have a cardioid, figure-eight, omnidirectional or other shapes of sensitivity field. Actually, this is what allows engineers to record different soundfields in the L and R channel with closely spaced mics: the distance between them would not provide any attenuation or delay to differentiate between channels.
The story is further complicated by the fact that loudspeakers also have a different dispersion pattern than real instruments (it's related to the ratio between wavelength and transducer area).
Also, different speakers have different recommended positions, e.g. Dynaudio recommends an apex angle of less than 60 degrees and no toe-in while Raidho recommends at least 60 degrees and a severe toe-in (with the speakers firing at the listener's shoulders).
Finally, there are very few "purist" recordings nowadays, and when you see a jazz trio recorded using 9 mics (or a solo violin using 3 mics) I may honestly state that your you should not be overly concerned by reproducing the exact angle between mics.

Regards,
Costin