Who positions their speakers straight ahead (zero tow in) and why.

The formal answer is that toe in affects tweeter rolloff, the width of the sweet spot, the treble to midrange balance and early reflections.  There's also the issue of some excellent tweeters may have resonances which completely vanish a little off axis.

Many speaker brands are designed to optimally perform with little or no toe-in.  I include:

• Magico
• Focal
• Revel

Magico and Revel in particular have great imaging across a wide listening area when placed with little toe-in and plenty of space to the sides and rear.

A little history may be helpful.  In the last 30 years or so tweeter manufacturing has come a long long way.  Cheap (< $50) tweeters often flat past 20 kHz, wide dispersion and low energy storage.  In the old days this was the realm of exotics, and if you wanted to hear everything you needed to point the speaker right at your head.

A related issue IMHO is the tweeter height.  Some speakers, like B&W, really should be listened to on mid-range height, not tweeter height.  So in general the best listening position for many speakers in the 21st century is with little toe in and perhaps significantly below the tweeter's laser like axis.

Harbeth  40.2,  backs against the wall and pointed straight ahead.These are a deep cabinet speaker and I just don't have room to pull out. I've always liked the sound from these speakers and haven't tried different arrangements except a little toe in. I find with no toe in the imaging is really good.

If the soundstage is more enveloping only if you fire forward, there are some deficiencies in the speaker. You compromise optimal sound power and the perception of it when firing forward, for example. The only exception to firing directly at the listener is.. concentric drivers. for instance, (slightly off axis is the way to go)...or some niche design like the Polk L800 SDA array, which malfunctions if you point it directly at ya.

Spendors, straight ahead. Better soundstaging. Nothing to do with hot tweeter.

 

Room, speaker and somewhat system dependent. Focal Aria’s with narrow baffles and clear, clean (not bright, but extended) tweeters set up with very little toe-in. Klipsch Forte’s in same system toe-in almost 45 degrees. I fiddled with placement A LOT!

Both have wide holographic sound stage that extends beyond the cabinets and can disappear with a good recording. The Klipsch soundstage is wider, taller and deeper. I’d say the Focal soundstage is more warm and intimate. I love them both, just depends on music playing, time of day and mood I’m in which set prevails.

Speaker toe-in is room and speaker dependent.  Vivid recommends toe in with beams crossed just in front of your head in your seated listening position.  I gradually toed out until I achieved the best balance between frequency response and staging/imaging.  The beam crosses behind my head.  If I approximate angle, towed in is 15-20 degrees.  My listening room is my living room in my small house, so I am limited and from a room perspective. I rate the room poor; but it’s the best I can do.  No toe-in reduces image density and affects frequency response in my room with my speakers.