Unsurprisingly, if you are using or thinking of using unpowered (or “passive”) speakers, it will be necessary to couple them with a power amplifier. It isn’t as easy as just hooking up any speakers with any amplifier, however. The amplifier has to match your speakers in two ways: It has to match the impedance (the ohms) of the speaker and the power (the watts) has to be right. Matching the ohms will be simple as the speaker will be either 4 or 8ohms. Matching the power is a little more complicated. In order to not product a distorted sound, so if you are using a 100W amp into a 400W speaker there shouldn’t be any problems. As a general rule of thumb, the PA should be as powerful as the entire instrument amplifiers put together – consider the drums as 100W. At Musician’s Friend we have precisely the live power amplifier to suit your needs. Popular products include Crown Live Power Amplifiers and QSC Live Power Amplifiers. As with everything we sell, all our Live Power Amplifiers are supported by our price & satisfaction guarantees and free standard shipping now applies to all orders over $25, including many heavy items.