Harmony Central Expert Review
Chris Loeffler is a multi-instrumentalist and the Content Strategist of Harmony Central. In addition to his ten years experience as an online guitar merchandiser, marketing strategist, and community director he has worked as an international exporter, website consultant and brand manager. When he’s not working he can be found playing music, geeking out on guitar pedals and amps, and brewing tasty beer.
Keeler Sound ReWave Acoustic Preamp
A new way to hear your acoustic guitar...
by Chris Loeffle
The acoustic guitar’s general design has been dialed in for centuries, suggesting we’ve taken it about as far as it will go. When someone steps up and says they’re found a way to significantly improve any acoustic guitar’s tone with an accessory you drop in the guitar’s soundhole, it seems like maybe it's time for a healthy amount of skepticism. However, that’s just what Keeler Sound’s ReWave acoustic preamp claims to do...does it?
Referred to as a “sound processor” and “natural preamp," the ReWave is a wooden device with multiple chambers and sound holes that inserts into the soundhole of almost any acoustic guitar. It's available in natural maple and flat black colors in three sizes, as well as contour or flat cutouts, and has an adjustable diaphragm in solid or slotted configurations.
What You Need to Know
The theory behind the ReWave natural preamp is that by eliminating feedback and sonic bottlenecking that happens within the body, it's possible to eliminate unpleasant soundboard production and muddiness. Their approach involves focusing the string’s energy into dedicated ports to reduce ambient noise entering the body, and refocusing the acoustic wave from the soundboard energy leaving the body through the interior chambers of the ReWave and the bridge.
The ReWave installs by loosening your guitar strings enough (or removing them, if you prefer) to place it flush in your guitar’s soundhole. Small rubber nibs secure the ReWave in the soundhole without any tools needed, and the slight lip sits flush with the guitar’s soundboard for a snug and solid connection to the instrument. The six small brass string ports aligned perfectly with the strings in three different guitars I used to evaluate the ReWave, and even with different fretboard/sound hole styles I didn’t find an issue securing it every time. You can change the diaphragm depth by physically pulling it closer to or further from the soundhole, but the change is subtle and not necessary. For those who want to just "drop and play," it comes set at the general recommended depth.
On all three guitars, the ReWave undeniably added some volume (around a 20% perceived boost) and cleaned up the acoustic tone in a noticeable manner that also somehow didn’t dramatically change the tone. The ReWave genuinely is the physical equivalent of an EQ touch-up, with a more focused low end, rich midrange, and shimmery highs in the treble in all three guitars and significantly less acoustic mud. My Breedlove dreadnought produced the same brash, cannon-like tone and projection I’m used to with the ReWave, but there was more space between the frequencies for the high strings to shine through. My Taylor 814, already an exquisitely balanced guitar, sweetened up even more with the ReWave installed and demonstrated even more individual note definition.
For serious tweakers, there is a one-time hassle to experiment with various diaphragm depths to find the one that best fits the guitar and desired sonic results. You have to loosen and then retighten all six strings between every adjustment, which also makes it challenging to remember any sonic differences between the settings.
The Keeler Sound ReWave is one of those pieces of gear that seems like a gimmick until you actually put it to use. It did everything it claimed, including producing more volume and balancing out a guitar’s acoustic tone without altering the guitar's character.
But would I put this in a $3,000 guitar? I surprise myself by answering, “Absolutely.” While there are times the visceral rawness of the standard acoustic guitar experience is what I want, I absolutely experienced sonic enhancements in instruments I already considered highly polished. -HC-