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Screenshot 2015-03-31 10.29.54

Premier Guitar just posted my latest Recording Guitarist column. The subject: Capturing the haunting reverbs of Southwestern ruins via impulse-response reverbs.

Many years ago I marveled at the eerie reflections within the stone-walled ball court at Wupatki, an hour north of Flagstaff, Arizona. On this visit, I attempted to clone the tone. I did the same at the Wildrose charcoal kilns in a remote, mountainous corner of Death Valley. The article includes audio clips, tech notes, and a download link for the impulse responses, suitable for use in any IR reverb program (or in the Logidy EPSi stompbox).

Screenshot 2015-03-31 10.42.24 — The 1870s charcoal kilns of Death Valley generate a spooky,, flange-like reverb.

Like a dope, I’d forgotten to bring the relatively high-quality recorder I’d intended to use, so I worked with noisy, lo-fi recordings from my iPhone 6’s Voice Memos app. After some digital cleanup (detailed in the article), the results were cool and compelling, though not a completely accurate audio snapshot due to various types of distortion.

(Actually, I had an earlier experience capturing quick-and-dirty reverbs when I visited the Neolithic caves of France and Spain last year. It wasn’t my idea—I just happened to wind up on a tour group with composer Craig Safan, who was conceptualizing a piece inspired by those evocative spaces. He’d packed a proper Zoom mobile recorder, and we made ad hoc impulse responses by clacking small stones together. Craig has since completed the work, Rough Magic, and he tells me his mixing engineer wound up using our IRs a great deal. I’ve heard the piece, and it’s awesome. It’s not public yet, but I’ll tell you when it is.)

Since writing this Premier Guitar piece, I’ve been pondering whether damaged/distorted impulse response files might be an interesting avenue for sonic exploration. Generating cool sounds via weird IRs isn’t a new idea—the Space Designer plug-in in Apple’s Logic Pro includes a little-known IR preset folder titled “Warped,” which uses unusual sources like synth tones and noise bursts to generate reverbs not found in nature. But my interests are reverbs that are both familiar and surreal—the echoes of distorted reality.

And coincidentally, just as I was writing this post, a friend sent this wonderful video: an old Teletubbies clip, processed through a smeary, distorted black-and-white filter and paired with Joy Division’s “Atmosphere.”

I’m pretty much talking about an audio equivalent to that video processing. Has anyone else thought about or explored this idea?

Logidy EPSi Review:
The First Customizable Convolution Reverb Pedal

One of the coolest gizmos from last weeks NAMM show is already in my grubby little hands: It’s the Logidy EPSi, the first customizable convolution reverb pedal. I ordered it the instant I heard about it, and it arrived right before I left for Anaheim.

Convolution (or impulse response) reverbs can mimic acoustic spaces and outboard gear with astonishing accuracy. (If this concept is new to you, check out this article by me. Or better yet, this one written by someone who knows what he’s talking about.) Nutshell: You create impulse response (IR) files by playing and recording a test tone in rooms or through gear. Once you load the file into an IR reverb device or plug-in, it can make anything sound as if it was recorded with the same ambience.You can also generate eerie, otherworldly sounds by loading unusual audio files.

Many software and hardware amp and effect modellers use IRs to mimic gear. Software convolution reverb plug-ins such as Audio Ease’s Altiverb, Logic Pro’s Space Designer, and Waves IR1 include reverb libraries, and also let you load your own IRs. But as far as I know, EPSi us the first device that lets you load your IRs into a stompbox and access them without playing through a computer.

I’m psyched to add IR reverbs to my (mostly) analog pedalboard, and EPSi makes it relatively easy to load the IR libraries I’ve compiled. The files require special treatment: They must be 44.1kHz WAVs, and the names must be formatted quite specifically, as detailed in Logidy’s documentation. The interface is extremely minimal: just a bypass footswitch and a knob/button pair to navigate the simple menus.

This unique reverb stompbox sounds great and offers limitless opportunities for creative sound design. You can load your own impulses, or add ones from from some of the fine freeware libraries online. (Thanks for the link, Scott!) On the downside, it’s difficult to load or edit sounds on the fly, so while it might be fun to spelunk for new sounds in the studio with EPSi, don’t plan on modifying sounds onstage. (The ability to recall several saved presets would vastly improve EPSi as a gigging tool.)