Tuning your Guit

Ok, so everyone should have by now learned how to use an electronic tuner.  If you’re new to this however, it can seem simpler than it is. Lets start with the basics:

1. The Electronic Tuner

The tuner you choose can make a difference. I went through a couple before I actually settled on a Snark. The Snark (http://www.snarktuners.com/prod_gb1.html) that I use is simple, has some decent features, and works with both electric and acoustic. Probably not the choice for a gig situation, but it’s accurate and very fast, so it’s exactly what I was looking for. The others that I’d tried were just as expensive, but much slower response, and definitely not as accurate acoustically.

2. The Guitar Intonation

It’s important to make sure your guitar is properly intonated. This means that when you fret a note, the note doesn’t go sharp or flat by the process of simply fretting it. You can look this up on the web and do it yourself, or bring your guit to a luthier or guitar tech and have them do it. Some guits are simpler to intonate than others, so it probably depends upon your particular gear as to whether you do it yourself or have someone else do it for you.

3. The Strings

Although string brand and type are dependent upon your gear and your particular tastes, it is important that you have relatively fresh strings installed. “Fresh” is a matter of how well you care for your gear as well as personal preference to an extent, but we should stress that as strings get “old”, they will be less likely to sound clear and true. Some people insist you need to change your strings as often as every month. I think this is ridiculous and a waste of money. However you should start considering a change at the very least every 4 months or so with regular play. Strings get flat spots at the frets, and also get “tempered” or harden. The harder the strings, the more fret wear you’ll get, but still, it’s up to you.

 

4. Tuning

Ok, onto the meat of this. With your tuner connected to your guit and powered on, we’ll start by rough-tuning the guitar. That involves simply plucking each string in turn, starting at the fattest one (low E) and turning the tuning machine until the tuner shows it’s reasonably close to what it should be based upon what your electronic tuner indicates.  This should get you reasonably close to being perfectly in tune. My experience has been that the low E seems the most difficult followed by the B string. You should try to pluck the string with the same amount of force each time, and the force should be moderate (not too hard, not too soft) as the louder the string, the more likely it will be to produce harmonics, which can affect the way that the electronic tuner responds.

Next, we want to tune to the 12th fret harmonic. Picking a harmonic simply is resting your finger on the string at the fret, without actually pressing the string against the fret, and then plucking the string (pick or fingers) and releasing the string at the same instant with your fretting hand. You’ll hear the note ring-out, but differently than if you actually had fretted the note. If you tune each string in turn to the 12th fret harmonic, you’ll be that much closer to a perfect tuning. Again, pay particular attention to the A string, as our next step is based off of that string.

Final Comment: There is some following of people tuning to 5th and 7th fret harmonics. I know skilled guitarists that do this, and I did until recently. However after reading about the the actual results of what 5th/7th fret harmonic tuning actually accomplished, I’ve decided to stop doing it. It seems that by doing this you’re actually putting your guitar out of tune, not in tune. Tuning string-to-string actually sounds like it should make sense, but it seems in reality it can put it out of tune by as much several cents from what it should be. This seems unacceptable to me, but feel free to correct me if I’m wrong – I’m sure I’ll enjoy the debate regardless of the outcome!

How is my Guit like a radio?

Radio waves work by radiating energy through space (it doesn’t need air, it just needs space). Radio stations work by radiating a specific frequency of radio waves. For instance, if your radio station operates at 590 on the AM band, it means that the station is radiating energy at a frequency of 590 kHz through space. In order to receive the signal from that particular radio station you need two things: an antenna, and a receiver that allow you to isolate that frequency from all of the other frequencies available.

How does an antenna work?

An antenna is made specifically for a particular frequency or frequency range. In the case of the AM radio, it is specifically designed to receive best somewhere right around the middle of the AM band. It’s total effective length is some fraction of the wavelength of the frequency. For instance, the wavelength of the 590 AM station we discussed earlier is 508 meters long. So, at the speed of light, in the time that the wave starts at zero, go to full positive amplitude, back through zero, to full negative amplitude, then back to zero, the total distance it would have travelled is 508 meters, or 1668 feet. This means that to receive that frequency, you need an antenna that is effectively that long, or some exact fraction of that. Fractional sized antennas are typically 1/4 wave, 1/2 wave, 5/8 wave or full wave of the wavelength, depending upon the frequency in question.

For our 590 AM station, a 1/4 wave antenna would have a length of wire of around 417 feet. Now, that’s obviously not the actual length of the antenna in your AM radio. Typically those can use an even smaller fraction (1/8 or 1/16 wave), and that’s only and effective length, meaning that other components (a loading coil or inductor) are actually making up the difference via electrical mechanisms such as ‘phase delay’. It’s not entirely relevant to this article, so I won’t get into detail, but suffice it to say that an antenna is a length of wire very suited to producing an electrical current when exposed to an alternating electromagnetic field (a radio wave). As an end-note to this paragraph, a typical single-coil guitar pickup has between 3000 and 5000 feet of wire on it, however it’s configured in a coil form with a ferrous core, which makes it an inductor, which means on the whole, it’s a very effective antenna.

What’s the receiver do?

Now that we understand that the antenna is the actual thing that detects a particular signal, what is it that the receiver does with this? The thing to understand is that although the antenna is “tuned” to the frequency to receive, an antenna by itself is very indescriminate. The antenna will receive a very wide range of frequencies, but it’s range is centered on what’s known as it ‘resonant frequency’. The resonant frequency is the one that it’s particular lenght is tuned for. So, how do I get just that 590 AM or 590 kHz frequency without anything else? You use a receiver, which filters out the adjacent frequencies using various mechanisms. The major component of this sort of filtering is what’s known as a bandpass filter. The bandpass filter can be a single filter mechanism, or it can be a combination of a high-pass filter and a low-pass filter, where the resulting overlap is the desired detection frequency. Basically, that’s all a reciever does – filters out everything above and everything below the desired frequency. Mind you, that’s a very simplifed description, but it covers just enough so that we can move forward.

And now the guitar part…

So, when you apply what you’ve just learned to your guitar, it’s now easier to see why you’re getting all that noise. In the way that your guitar has been built, it’s a very effective, albeit weak, wideband receiver. Given that the strongest radiated signal in your home comes from either your wiring or some other source of electrical device, that’s what you’re most likely to hear when you amplify it.

Some of the sources of that hum in your home or at a gig can be things like light switches, flourescent lighting, electrical motors (in refridgerators, air conditioners, sump pumps, etc), or possibly even from the transformer or wiring out on the street. All of these things will radiate energy and noise (known technically as EMI or RFI) in exactly the same way that a radio station transmits a signal, except the the energy radiated is not typically on a narrow band like the 590 kHz station. It’s more than likely across a relatively wide band comparitively, along with various “harmonic” frequencies. Harmonic frequencies are just like the ones in music, in that frequencies that are multiples of the original frequency can resonate along with the primary frequency. All of these things contribute to that “60-cycle hum” you hear so much about, and answers the question “how my Guit is like a radio”!