I have a Laney RBH800 Bass head. Using a 8 ohm 450W RMS 15" Speaker. The amp is 300W RMS. The amp blew and I had to replace the PC board under warranty (luckily) The amp states that "no less than 4 ohms be connected at any one time" underneath the speaker input jacks. Is there a problem with my amp speaker configuration? The supplier whant's me to pay for the repair because as they say I blew my amp. It was dead when I switched it on for $%^ sakes! I just need to know if my amp speaker config is right then I can #$% them up if they whant to make me pay! Any help will be appreciated.