Mackie power amp bass trouble

[Deepdark]

Hi there

A friend of mine has a Mackie SA1232. Long story short, someone with a bass guitar, a mixerand the power amp loool. He abused it for like 5 to 10 minutes before it start smelling fun. There is no burning traces, but now lows rumble. I'm pretty anal with amps and power amps. My first thought was that maybe the input signal was just abusively high and the input opamp (NE5532) had a hard time.  Mids and high freq. are ok, only the bass rumble and changing the sub speaker didn't solved it. Is it possible to be in the lows circuit?

 

[Deepdark]

schematic is here: http://music-electronics-forum.com/t37084/

 

[nashkato]

Why do you call this topic "power amp"
The Mackie SA1232 is a powered speaker with 2x12" Sub speakers

start at the speakers and work your way back to the poweramp .
i don´t suppose it´s somewhere at the input .
Most probably the speakers , if the sub amp still seems to work

 

[Deepdark]

Thanks a lot. Yeah power speaker, sorry. I'll work my way from the speaker sub to the input then. Thanks