Thanks MF.
i have set up a meeting with an audio engineer for later this week.
over the phone he suggested that the crossover of the unit MIGHT be the reason, and that based on how i described the sound to him.
I understood what you said earlier : "Physical damage caused by being played too loud by low-powered amps that are being pushed beyond their clipping-points.", but what i actually meant was that which other part (than the speaker (baffle)) can be the reason to such a sound? for example, the DAC, crossover, board etc. ( i'm not expert, so appologies if i am not employing the corret sound terminology)
Let me know your opinion on that.
Regards