I can offer what I find to be nearly ideal for my 2.4 listening position/setup. Speakers 8' apart center-to-center, toed-in 10 degrees each or less, grilles on. 9.5' coax to my ear. 38" listening height. I use the coax as my reference point as that defines the source of the most-directional sound and imaging and phase information comes from when making small adjustments to position.
But I've used the spikes to tilt the speakers back an unspecified amount, a little bit because my ear is 2" higher than design, but mostly due to having more vertical latitude for frequency balance. Stereophile's vertical response graphs illustrate (though perhaps at too close a distance) that response above the coax axis sucks-out the lower-mids, and below the coax further fills-in the lower-mids. So even if I give up some degree of time/phase coherency by tilting the speaker further back (altering arrival times ever-so-slightly from spec) I get more wiggle-room before midrange suck-out.
Additionally, each speaker is pretty much in free-space, 6' from cabinet edges to either side wall and 3' to a 'soft' back wall, 6' to a 'hard' back wall. Nothing at all diffractory around the speakers or between the speakers and my ears, or even to the sides, after a little living room tweakage for a proper listening session, ie move the coffee table behind the speakers rather than right in front of the couch.
A thick pile carpet, soft cushy furniture against the back wall, and an 8'x2' acoustical absorber behind the couch/listening positions.
RTA shows a lumpy low-frequency response due to my open floor plan asymmetrical living room (though this also puts 25Hz at 0dB ref 1kHz!), but otherwise lets the Thiels be Thiels with as little room interference as possible. So I'm fortunate my current living space allows for such a great setup for any speaker to sound their best.
But I've used the spikes to tilt the speakers back an unspecified amount, a little bit because my ear is 2" higher than design, but mostly due to having more vertical latitude for frequency balance. Stereophile's vertical response graphs illustrate (though perhaps at too close a distance) that response above the coax axis sucks-out the lower-mids, and below the coax further fills-in the lower-mids. So even if I give up some degree of time/phase coherency by tilting the speaker further back (altering arrival times ever-so-slightly from spec) I get more wiggle-room before midrange suck-out.
Additionally, each speaker is pretty much in free-space, 6' from cabinet edges to either side wall and 3' to a 'soft' back wall, 6' to a 'hard' back wall. Nothing at all diffractory around the speakers or between the speakers and my ears, or even to the sides, after a little living room tweakage for a proper listening session, ie move the coffee table behind the speakers rather than right in front of the couch.
A thick pile carpet, soft cushy furniture against the back wall, and an 8'x2' acoustical absorber behind the couch/listening positions.
RTA shows a lumpy low-frequency response due to my open floor plan asymmetrical living room (though this also puts 25Hz at 0dB ref 1kHz!), but otherwise lets the Thiels be Thiels with as little room interference as possible. So I'm fortunate my current living space allows for such a great setup for any speaker to sound their best.