RAISING THE TONE
in his new column on tone, Jamie Dickson examines the relationship between wood, resonance and sustain
Guitar folklore abounds with ruleof-thumb methods for testing how resonant and responsive an electric guitar is without actually plugging it in. Needless to say, there’s a whiff of snake oil about some of these methods. Here’s one I recently heard put forward by a guitarist of many years’ experience – if you tap the neck and the body of a guitar with your knuckle and the ‘note’ produced is about the same in each case, then that’s the mark of a good-sounding guitar.
On the face of it, it seems plausible. After all, if the body and neck ‘agree’ in pitch when you tap-test them, shouldn’t that lead to a more harmonious, longsustaining guitar? Intrigued, we got in touch with veteran luthier Patrick James Eggle to get his highly experienced take on the question. Interestingly, his view is that you probably don’t want your body and neck to resonate at exactly the same pitch.
“I’ve spent lots of time tap-testing bodies, especially with the acoustics,” Patrick says. “But I’ve never tap-tested bodies against necks. I think that if the body or the neck or the instrument, as a whole, is extremely resonant in one place – in other words, if you tap-tested them and both sounded the note of G, let’s say – then that might give you a dead spot in that note.
“Here’s what I mean by that – if you have an instrument that’s very responsive to a certain frequency, you’ll be playing and the guitar will ring beautifully, but then you hit a certain note and you feel the instrument ‘jump’ and the string instantly dies. You can watch the string vibration die away almost immediately because the guitar’s body is resonating [excessively on that particular note] and taking the energy away from the string really fast. So if I was going to tap-test a neck and a body I would want them to be mismatched in order to avoid a strong resonant peak in the guitar – because that would give me a dead spot.
“It’s easier to see that effect in action on acoustic guitars,” Patrick adds. “A lot of acoustics sound great up to about the 7th fret but as you go higher up the fretboard they start to sound weedy and small. But with the best acoustics, you can go right the way up to the body and the notes still sound full. I think that’s the case with electric guitars as well, to a degree. You
“The challenge of balancing sustain, voicing and resonance in a flattering way is at the heart of the luthier’s art”
want them to be responsive and good all over the neck. When they aren’t, it’s normally because they’ve just got a huge resonant peak somewhere that takes the ‘engine’ of the guitar’s tone away.”
Good Vibrations
This phenomenon sheds light on an important question – what do we actually mean by ‘resonance’ when we’re talking about guitars? To some people it means zingy, long-lasting sustain – but to others it means a loud acoustic response and a lively feel of vibration in the body. These two qualities don’t necessarily go hand in hand, Patrick argues.
“If you have a guitar that’s very light and resonant, then you get that loud acoustic ring to it that gives it one kind of resonant quality. Whereas, if you have a guitar where the actual body and neck are like a piece of concrete, for instance, then the string physically vibrates for a very long time because there’s none of the energy from the strings being absorbed by the body. So there’s more sustain but it’s not coming from the resonance of the guitar’s body as such.”
Balancing these two factors in a flattering way is a key part of making guitars that sound and feel good to play. But getting this equation right is further complicated when you have hollow or chambered spaces in the guitar, as you might find on Thinline Telecasters or weight-relieved Les Pauls, for example. So what effect on resonance, tone and sustain does chambering the body have?
“With our Macon model, for instance, some of those bodies are not chambered at all, while some are semi-chambered and others are fully chambered,” Patrick says. “Normally the reason we do that is to hit our target weight because that’s what our customers want – they want a Macon style of guitar to be between 8 and 8.5lb, as a rule. And usually if we aim for the right weight then we seem to hit our target tone. However, if you take a really heavy piece of mahogany and then chamber the hell out of it to hit your target weight you can end up losing mids. Very heavily chambered electrics can be all bottom and top end and it doesn’t sound the same anymore.”
The challenge of balancing sustain, voicing and resonance in a flattering way – while still ensuring the guitar is comfortable to play – is at the heart of the luthier’s art. But even when every effort has been made to settle on an approach that works consistently well, wood is – at the end of the day – an organic material that naturally varies in character. So every now and then it throws an unexpected curveball at the guitar maker.
“People used to say that any guitar that you put EMGs in will sound exactly the same as any other guitar with EMGs,” Patrick says. “But I actually disagree with that. I once had this line of guitars that had been built in America, mainly, but I was assembling them Amsterdam. It was an odd little business that we had. Anyway, I was assembling 12 guitars and they all had EMGs in – same set and everything, prewired from EMG. We had a big event happening the following day, so I was working to get all 12 of the instruments ready in time,” he recalls.
“Anyway, I put the strings on one particular guitar and it was half the volume of the others. I tested the wiring and that didn’t turn up any obvious problems. So I called EMG and they recommended this, that and the other. But nothing worked and in the end I just took out the whole pickguard and put in a completely new set of EMGs – but it still sounded exactly the same. So it was just the guitar – that particular one just sounded weedy. It’s something I’ve always remembered. Guitars do vary in character and you can’t always fix that with electronics.”