Moving the sweet spot

It's tricky. Sweet Spot A is better at different things than, say, Sweet Spot B.

In your original listening position, have you tried toe-in to the point that the drivers are facing you?
Or tilting the speakers back (rake angle)? The angle would depend on the size of of your room.

Yup lowrider57 has got it. Adjust one speaker for one ear. Set the camber, caster and toe in/out THEN closer or further for DB gain or loss for your ailing ear.

I found the biggest thing about the seated position is height in relation to the Bass roll off and the HF being there but not beaming and boiling your ears to death...

Painters tape a square and a tape measure. You want to get real picky laser line placement or string lines to your head in the seated position..

You can get REAL picky...

A mic stand and some tape to hold the string lines at the speaker and stand.

You know Master M has two different spots he listens to. I can't remember the reason but both have their strengths and weaknesses for listening.

Maybe he'll chime in..

Regards

You may want to experiment with different chairs, too?
And when you identify each chair's respective strengths and
weaknesses, you can adjust for effect.