It was a wonderful article by Steve Lampen, “The Truth About Guitar Cable” in Jan. 14 RW. Just an observation, if you please.
Anyone who listens to guitar or who plays it can clearly hear the differences between an acoustic guitar and an electronic guitar. The acoustic instrument sounds mellow, round, full. The electronic variant has a comparatively harsh sound.
Now, anyone who has ever played with function generators knows that square waves sound less pleasant than other waveforms. The distortion, as we think of it, is due to the rich content of odd order harmonics. By comparison, instruments that sound mellow are rich in even order harmonics.
Steve points out that the highest frequency fundamental produced by a guitar is 1319 Hz. To produce at least the timbre of the electronic pickup, it’s reasonable to think that the third and fifth harmonic would be important. The third harmonic is 3957 Hz, which is nearly reproducible via a standard POTS phone line. The fifth harmonic is 6595 Hz, still not an amazingly high frequency.
On the other hand, suppose you used a cheap guitar cable and could not reproduce frequencies above 1500 Hz. Your guitar would sound more raspy with the lower frequencies (the low E would be 329.75 Hz except for the need to tune slightly off due to perceptual criteria that make precise frequency differences sound wrong) than with higher frequencies, because the harmonics would be absent.
On the other hand, if your cable passed up to 2700 Hz but not as high as 4000 Hz, it might sound more acoustic due to the absence of odd harmonic content, but the presence of second harmonic content.
I grant that this is all guesswork, as I have not done any testing to determine these impacts or effects. After all, we all know that theory and practice do not necessarily match up in the field.
Tom Norman, CPBE
Sr. Engineer
Burst
Centennial, Colo.
