Taming the piezo quack
I have a Baggs Element in a Martin rosewood dreadnaught. I have played it through 5 different PA systems and never found the piezo "quack" to be objectionable. In fact, it was barely noticeable and I really like the sound of the Element. I recently bought a Fishman Loudbox Mini and as soon as I hit the first chord, I thought, now I understand the term quack. Is there something about an acoustic amp (or this particular amp) that would make the quack more pronounced? Or does running into a mixer (either with or without direct box) somehow reduce the quack? Can it be reduced with proper EQ? I am currently using the recommended amp settings of slight bass & treble boost and slight midrange cut.
Thanks for your question. The piezo "quack" is an accentuated response to a particular mid-range characteristic. It's most noticeable when the plectrum touches the strings and when the vibrating strings contact the frets, both pressing and releasing. You'll hear it particularly strong when you slide a string up the neck. The mid-range control on the Loudbox Mini may not be centered at the same frequency that makes the quack most apparent.
It will be helpful to use a device that offers EQ with adjustable frequency mid-range controls. Our Venue DI and Para DI models each have adjustable mid-range frequencies.
One way to use that would be to boost the mid-range and adjust the frequency to find which makes the quack its worst, then cut that frequency.