I think determining what is right in regards to the soundstage height is based upon personal preferences. I would set yor listening position at a height that is about even with the midrange and tweeter elements of your speakers if they are arranged with the midrange in the center and tweeter on top. This will allow you to position the speakers with directional energy of those two drivers and help you pick the depth and how wide you want the soundstage to appear, for example, with no toe in, the stage will be wider, but you may suffer some loss of coherence in instrumental detail. As you toe in, the details become more focused but with some loss of soundstage width. In regards to depth, I find that having the speakers far from the wall behind them allows for a deep soundstage. Of course a lot will depend on your own listening likes and room conditions and equipment. I like the soundstage and depth where I am seeing (when I am closing my eyes and imagining I am at the concert) and hearing the performance as if I am about the 3rd to the 5th row back. For me and in my room this gives me the best sound and coherence. I also have my speakers slightly toed in, just right of the listening position and of course the regular room treatments to tame reflections and echo. I also found that experimenting with treatment directly behind the speakers effect the soundstage and also can make the speakers sound congested if too much is used there. Funny you mention congested, I also experienced that with a needle going bad and no matter what how many times I cleaned it, it was sounding congested, I finally had to retip it and the congestion went away. Just an example of how similar variable symptoms we hear can be way off topic to the cause.
A lot of experiementing will have to take place. I still have the tape marks in my room from previous positions of loudspeaker placement. It will take some time to get it just right. I would suggest listening to various types of music as you experiment and pick out certain attributes, the whack of a kick drum or the vocals of musicians and listen to how your speaker placement effects the soundstage.
Good luck,
Audioquest4life
A lot of experiementing will have to take place. I still have the tape marks in my room from previous positions of loudspeaker placement. It will take some time to get it just right. I would suggest listening to various types of music as you experiment and pick out certain attributes, the whack of a kick drum or the vocals of musicians and listen to how your speaker placement effects the soundstage.
Good luck,
Audioquest4life