We played an outdoor show last night. Full PA support. Used an Ampeg SVT212AV. Stage volume was high, but not extreme. Problem: When standing directly in front of the cab, the tone was harsh, clanky, and wholly unpleasant. When standing next to the cab, or even 45 degrees or so to one side or the other of the cab, the tone became much more tame and pleasant, though somewhat diminished in volume. What is causing this? Any solutions or suggestions? I was DI’d to FOH, and I certainly hope that the crowd only heard the pleasant tones. If not, I must retreat to the caves at the edge of town and live amongst the forest creatures to repent for the shameful bass sounds I imposed upon the nice people at the concert.