I just recently bought the GS112 and GS112NT cabinets. I am driving the two cabinets with either a Randall RB750 (750 watts into 4-ohms) or a Warwick tubepath 5.1 (500 watts into 4 ohms). When I get to the mid volume level, I notice a buzzing sound coming from the tweeter, when hitting notes on the B, E and A string. If I turn off the tweeter, this all goes away. The 12" speakers are not distorting on either cabinet. If I am using just the GS112 (with tweeter, 8-ohms in this case), the same thing happens. I have thought that maybe my bass is overdriving the pre-amp in my amplifier, however the lows do not distort, it only comes from the tweeter. I have even tried other basses and the same thing happens. Lastly, even if I turn the tweeter level down to almost off. I am not sure if I am having a problem or not, but this does not seem to be normal to me. Any help or advice would be greatly appreciated.