In this segment from "Electrical Audio How-To: Microphone Techniques for Speaker Cabinets," Steve Albini explores the use of a ribbon microphone, specifically the STC 4038, for capturing guitar amp sounds.
He explains how the figure-eight pattern allows for significant flexibility by capturing direct sound with the front lobe and ambient room sound with the rear lobe. By adjusting the mic's distance, you can tailor the sound character, emphasizing either a more intimate bass response or a more spacious ambient presence.
Albini highlights the microphone's proximity effect, which enhances bass when placed close, giving a small amp a larger sound. This technique demonstrates how careful microphone placement can dramatically alter the sonic quality of a recording.