Aphex Bass & Acoustic Xciter pedals

For nearly three decades, crafty engineers have been adding sparkle and life to studio, live, and broadcast mixes with Aphex’s unique high-frequency-enhancing Aural Exciter signal processors. Bass players found these pro-audio tone tools even more enticing in 1990, when Aphex added its Big Bottom low- frequency augmenting circuit to its line. These devices were once available only as rackmount line-level units, but Aphex’s new battery-powered Xciter pedals feature the same Big Bottom and Aural Exciter processing in compact battery-powered stompboxes that accept active or passive instrument levels. The balanced xlr output means the Xciter pedals can also serve as enhanced direct boxes.

Portable Xcitement
While the Xciter pedals are Aphex’s first stompboxes, it’s obvious their designers understand the perils and issues encountered in the floor-dwelling domain. A cast-aluminum box houses the internal circuitry, while the short and resilient rubber knobs minimize the pots’ vulnerability. The bypass footswitch and the knobs protect the effect-status LED—it’s nearly impossible to crush it with an errant boot-stomp. You won’t be tripping over cables, either, since all of the jacks (and the selector buttons) are conveniently located on the side away from your foot. And since the tiny buttons are positioned adjacent to the jacks, your cables shield them from danger.

You have to remove four screws to replace the 9-volt battery; a hatch would be more convenient, but Aphex estimates you’ll get between 100 and 150 hours from an alkaline battery. If you prefer external power, you’ll dig this: The Xciter pedals are equipped with unique circuitry that lets them run off virtually any external power supply, ac or dc, with a wide range of voltages. That means it will be easy to incorporate the Xciter into your pedalboard, and you probably won’t have to buy another adapter. (Doesn’t everybody have a few wall warts lying around?)

The Bass Xciter and the Acoustic Xciter share similar circuitry, but the lo tune and hi tune frequency ranges are slightly different. The Bass Xciter’s lo tune range extends down to 30Hz to accommodate a 5-string’s lowest notes, while the Acoustic model bottoms out at 40Hz. According to designer Donn Werbach, the Bass Xciter’s Aural Exciter produces more harmonic content for a more up-front and aggressive sound, while the Acoustic Xciter’s harmonic generator is fine-tuned for a more transparent, natural voice.

Xtending The Boundaries
Like their rackmount relatives, the Xciter pedals excel at extending a speaker cabinet’s perceived frequency response without requiring additional amplifier power. That’s important, because extending the frequency response with EQ and sub-octave synthesizers can push an amplifier and speaker beyond their limits.

Getting a 5-string’s lowest notes to speak authoritatively through a small combo is often difficult, but in our Soundroom and on the gig, the Bass Xciter was up to the challenge. It increased a Hartke Kickback 1x12 combo’s low-end heft and girth significantly. With the Big Bottom’s lo tune and lo blend knobs pointed straight up, an MTD Kingston sounded surprisingly full and deep through the little combo. It’s an improvement you’ll swear you can feel as well as hear; the sensation is akin to adding another cabinet.

The Aural Exciter section enhanced the Kingston’s growl and detail, and the texture became more complex with more air, space, and color around each note. The bass felt more vibrant and alive, with more articulate and expressive nuances. The MTD’s passive electronics sounded more effervescent, adopting more active-like sparkle and sheen. When slapping, top-end zing and clarity improved dramatically.

As an experiment, I tried the Acoustic Xciter with electric bass. The Bass and Acoustic Xciter units sound quite similar, but the Acoustic unit sounds a bit more open, relaxed, and clear. Some electric bassists might actually prefer its less sizzly texture. With either unit, I found the lo tune and hi tune knobs valuable for finding the perfect enhancement-frequency “sweet spots.”

Thanks to their high 10Mž input impedance, both units are perfectly suited for piezo-pickup-equipped upright basses. The Acoustic Xciter sounded more open and natural with my plywood Kay, but aggressive doghouse slappers might want to experiment with the Bass version as well, since it can produce a toothier bite and more percussive snaps.

These boxes record well, also. Unlike some DI boxes that deliver a clinically dull and lifeless tone, the Xciters add a lively richness that’s highly addictive. And they’re not just for enhancing small cabinets, either; they added impressive depth and detail to our largest test cabs as well.

If you’re looking for an economical way to beef up and add clarity to your rig, take a look at the Aphex Xciter pedals. When auditioning either pedal, be sure to bypass the effect occasionally—you’ll be amazed how the sound collapses and loses its vigor when the Big Bottom and Aural Exciter are disengaged. The difference can be dramatic—these pedals are amazing.