Good day mga sir, i have a problem on my konzert av502a suddenly stops outputting sounds, i had to maximize the volume to hear a sound, and that sound is very weak, bass not heard, parang tunog cellphone lang nilalabas, di nadin umiilaw ung led nang speakers ko (konzert 655 600w) nung huling gamit ko nito ok pa (last week). Tried replacing the rca cable and interchanging speaker cables but still same results occur, Any opinions about this. TIA!!