I’m not entirely disagreeing with dweller since I believe in leaving areas in the room untreated, but a wall of glass is terrible for sonics. If your front wall was plaster or drywall, then maybe don’t treat it. You could help the imaging of the speakers by adding partially closed drapes or curtains, or by using 2 vertical absorbion/diffusion panels, (portable). If you can limit the reflection from the glass, you will get a more focused image.
Your weak link may be the amp, but can you tell us what cables you are using? (speaker, IC, and power).
Your weak link may be the amp, but can you tell us what cables you are using? (speaker, IC, and power).