How's your room acoustics? Brightness at higher volume may indicate a "live" room. Even the cheap acoustic foam is better than nothing, but thicker the better, like 3 or 4 inch. I covered Roxul panels to good effect.
I agree with the amp suggestion to the extent that it won't be as shrill as the Arcam, but the better amp won't tame a shrill speaker and room.
I agree with the amp suggestion to the extent that it won't be as shrill as the Arcam, but the better amp won't tame a shrill speaker and room.