Thanks everyone. Like I suspected, no consensus. Same thing from my web searches. I read about a guy who went back to conventional toe-in although radical sounded better. Why? It «looked wrong»!
Sure, I will follow my own ears, but in this case I’m not sure. Is there something slightly «artificial» with radical toe-in? Or just my imagination? The one effect that I am sure of, regarding the front sound, is that the tweeters are a bit tamed – less direct beaming – with radical toe-in. Which can be OK in my case. I am also fairly sure that there are positive effects on the back-firing sound, as mentioned, although some are debatable (like more bass but maybe less tight from the room corners). I can well understand listeners who have used a long time, getting the angle right!
Ceiling and floor reflections – yes this is a valid point. I first overdamped the ceiling, and later removed most of it, to good effect. A silk carpet does a good job on the floor (not wall-to-wall). The speakers are designed to sound lively and immersive in a normal (not overdamped) room. They are big and heavy, and my back is not so good, so quick A – B testing is not easy. Disconnecting the back drivers would defeat the bipole speaker design. Likewise a lot of absorption or diffusion behind the speakers, although a little bit is fine.
So what do I do? Go back to conventional and forget the rest? My wife says, maybe radical is better, so why dont we keep it that way.
Radical toe-in is the main suggestion from the speaker designer, although other positions may also work well in a large room like mine.
My thinking might change if someone told me I am breaking a basic law of audio, my membership here should be withdrawn and whatnot! Has not happened yet. So I will keep it radical, for now.
Two more thoughts. I can easily hear differences in the sound from the frontfiring tweeters, depending on their angle. They can sound strident, a bit hard and bright, if pointing directly at my ears. When they point in front of me, they are ‘tamed’, as mentioned. How much depends on how far in front the crossing point is. Someone wrote, one foot is best, and this may be right in my case also. One or two. It depends on the tweeter off-axis sound, too far off axis is not good. Note that I am not trying to widen the sweet spot, it is OK as is in my room. The other thought concerns the crossing itself. With radical toe-in the main direct sound waves from the speakers (esp the treble) cross before they reach my ears. Does this create a kind of disturbance? Or ‘pre-processing’? Just speculating, here.
