That could very well be a setting issue with the hu..Just trial and error/playing with the hu to get the sound you want at certain volumes...too much mid,and bass settings can bottom out the speakers at the wrong settings/hz..Ill agree that that amp is great for entry level low volume sq,as clarion is known for from my experience..I would look into getting another decent 4ch amp of a min of 75x4 rms@4ohms,even an old school Alpine Duo-b 2ch for up front like a 3523/3525,4ch of like a 3555,some excellent sq,and loud amps,and budget wise,even a jbl gtq 400 is a great amp,gtq200,old school amps of course is generally what I seem to mention.New,SStreams Lil wonders seem to sound great for the Money to me.
Alpine amp 3554 oldschool BumpS!! | eBay is one BA amplifier that will perform fantastic for your staging!!