In this two-part tutorial, Nashville amp tech Skip Sims shows you how to replace speakers in a 4x12 guitar amp cabinet.
Sims installs a quartet of 25-watt, 16 Ω Celestion G12M Greenback speakers in a vintage 1968 Marshall basketweave cab and explains how to test impedance and polarity for the individual speakers and quad set, the best techniques for mounting speakers to protect their cones, and how to wire the speakers in Marshall's classic series/parallel configuration. He also describes how to break in new speakers after they're installed.
To view the wiring diagrams for this project, visit premierguitar.com/4x12-wiring. (This diagram is also embedded in the video.)
Bonus! Want to hear a 1968 Marshall half-stack in action? Check out the short demo following Part 2 of this how-to video.