Fine Tuning the Maton
Performing with an acoustic guitar is a challenge most of the time because of the possibility of the guitar feeding back.
A long time ago, I had determined that the Maton guitar I use has a resonance peak at F#, 4th fret on the D string. This was quite clear from the recordings I have done. For live gigs I had used a Yamaha preamplifier that had a tunable notch filter and this helped matters enormously. Much more control over the instrument.
I was however still concerned that that there were other resonance frequencies that I hadn't discovered. How do I find them?
While fooling around I discovered that if I sing into the hole of the guitar I can acoustically 'excite' the guitar. Resonance points are revealed by actually feeling the instrument resonate/vibrate. Using this technique, I discovered I had two other resonance points: One at F and another at B. The F frequency required a bit of effort as that is a low note, and it took me about ten to fifteen minutes to relax my vocals chords enough to produce a note that low.
So, in a nutshell, the resonance points of the Maton are from lowest to highest:
Now what to do?
I had looked around on the Internet for something to buy, but it did seem a bit hard, not that much around. The solution was sitting right next to me. I had a eight band parametric filter by Kawai that fitted the bill. I had used it while I was recording my CD's. I set up in the lounge plugged into the Fender amplifier and set up the three notch frequencies that I had determined.
A much better behaved guitar.
There is still an issue with the thump I get when I put the palm of my right hand on the bridge, but that is a technique issue.