I have a silverface Fender bassman 100 and I'm thinking about buying Peavey bass cab with 2 12" and horn (originally a 412TVX cut in half). Thing that concernes me is that my amp can run on 4 ohms, but cabinet's impedance is 8 ohms. How will it affect amp's performance? I know that power will decrease, but how much? I guess that I'll have to run amp nearly on maximum of power. Is it good for it? Please answer as soon as possible because I have to return it in a few days if I don't buy it.