Before I invested in GIK panels I rolled up a thick foam mattress cover (cut in half) and propped/tied them up in various spots to get an idea of the effects.The same could be done with a rock wool panel.Straddling the corners had the most effect,especially close to the ceiling.If that works for you they absolutely won't be noticeable at all.
If you decide on diffusion or panels on the walls both are easily made to become part of the decor.The panels can be ordered with art prints of your choice.
GIK did not charge me for consultation and the panels are returnable.Look around their site and of course other companies.You can send pictures,diagrams,and frequency measurements to help the people at the companys give an informed opinion.Best of luck!
If you decide on diffusion or panels on the walls both are easily made to become part of the decor.The panels can be ordered with art prints of your choice.
GIK did not charge me for consultation and the panels are returnable.Look around their site and of course other companies.You can send pictures,diagrams,and frequency measurements to help the people at the companys give an informed opinion.Best of luck!