A Back Buzz Test - What a Relief!
By Randy Reynolds/Luthier
Here is a little test for your guitar set-up and your reading skills. First, locate this chord and play it several times on your guitar with varying attack and left hand pressure:
In case your reading skills are as poor as mine, the chord is written in tablature over here on the right. Just for interest, this chord is from a Chopin Waltz, Opus 69 #2 from the B major section. Perhaps not a fingerboard position one plays regularly but useful for our purpose.
I have client, Randy Drake who visits me from Denver with his Contreras Double Top, a very wonderful guitar, but an instrument with some issues, namely the ability to generate unearthly noises as though possessed. This guitar has seen a fair amount of repair work with the result that the refretted fingerboard was very straight and couldn't be played without a fair amount of buzz. Over the course of a couple of visits I was able to minimize most of the problems, but Randy likes to be able to dig in and play with a very strong attack and eventually the Contreras would howl in protest. So nothing for it but to defret the guitar and add relief to the fingerboard. As you may know relief is usually needed in order for the guitar to be played with little or no buzz and with a more playable low action. Relief is often mistaken for forward bow in the fingerboard but the luthier usually places it there intentionally.
Randy came back to pick-up his exorcised guitar and was initially very happy to have finally have his old friend back in tip-top shape. But this too would pass and the following day Randy called to report that strange noises once again inhabited his instrument. I resorted to an old repairman's tactic by reminding him that I could fix anything that was broke, but since I couldn't fix his guitar, therefore it must not be broke. That stalled him for only a moment and recovering nicely insisted that we give it another try.
After an inspired session of fine-tuning action, frets and string choices, the guitar was performing well except for the chord illustrated above. When Randy would play it there was a substantial back buzz on the bass E string. I had been convinced that it was simply a matter of raising the string at the nut and the job would be fait accompli, but not so. I began to suspect that I had the relief too far forward on the fingerboard. I asked Randy to play the chord on three other guitars in my shop and lo and behold two out of the three had a similar back buzz! None of these guitars exhibited buzz of any sort previous to being asked to play Chopin's devilish chord. We finally did reduce the problem so that the back buzz occurred infrequently but in order to totally fix the problem would probably have created others.
Still, I will have to ponder the design of relief of the fingerboard and perhaps this F#7th chord will come to be a good standard test for proper relief placement and the playability of the guitar will benefit. You can contribute by trying this chord on your guitar(s) and letting me know the results. Also if you have any similar tests that you would recommend for a lonely luthier to try out on those cold winter nights, by all means pass those along as well. Thanks for your time and if nothing else perhaps you'll find that your guitar can make interesting sounds.
(Note: the information in this article is the opinion of the author, not necessarily CSGS or any other group, entity or person.)