Ribbon and electrostatic speakers do have different dispersion patterns from dynamic speakers.
Typically, sitting in the sweet spot, move a door mirror (Home Depot or Bed, Bath for a few dollars) along the sidewalls or ceiling. When you see the speaker in the mirror, that is where you place the absorption panel.
Typically, sitting in the sweet spot, move a door mirror (Home Depot or Bed, Bath for a few dollars) along the sidewalls or ceiling. When you see the speaker in the mirror, that is where you place the absorption panel.