So I was looking at some MarkBass stuff to upgrade my rig from the Acoustic B300H head and an old Peavey 2x15 that is probably older than I am. Problem is, the lowest frequency handling I see on the MarkBass stuff is about 40hz? That's no good for me! I'm a 5 string player pretty much exclusively anymore. Got a few fours I won't get rid of for sentimental value, but I gig out with my 5 string always. Is there a product of theirs that I am not seeing that can handle 31hz or less, or should I start looking elsewhere for my upgrade?