Hey! Before you go pluggin your amplifiers into a buncha speaker cabinets, be sure to take a look at Roger Sadowski's informative, and preventative, posts regarding impedance. He even has an Ohm Calculator through his site to calculate exact ohmage when running speakers in parallel. If yr playing outta some nice vintage amps into some special cabs, be sure yr doin everything correct so you don't blow anything up. You're welcome.