i have a behringer ultrabass bx300 combo (the 30 watt one). I am ready to upgrade. Now its going to take a while for me to save enough for a new head and cab.(dont suggest used, i've thought it through, i want brand new gear, period) So it makes sense to me to buy a cab first. if i bought the head 1st it would collect dust until i got a cabinet. but it seems if i get the cab, i can power it with the combo until i get a new head. the speaker in the combo can only handle about half volume. i figure with a different cab, I can leave it turned all the way up. The cabinets in paticular im looking at are the Ampeg BSE-410HLF 4x10 and the Ampeg SVT-410HE 4x10, and a Ampeg SVT-410HLF Enclosure. First of all what are the difference in these cabs. I don't see any obvious difference in the specs and the price is $100 more for the svt-410hlf. second of all will these cabs work with the above mentioned combo. i dont know the ohm load of that behringer. the combo does have a preamp out on it any help would be greatly appreciated.