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So, I'm about to ask one of those questions that I know there is no one correct answer for - too many variables, etc.

However, I'm nothing if not curious (and stubborn) so hear goes.

My latest - a black walnut/sitka OOO is finished, with some significant tweaking still necessary (does it count as tweaking if you have to remove the neck?)
Ahem - the short story is that I was in a hurry and when glueing the neck on and the fretboard to the neck I concluded that "close enough" was close enough in terms of the neck angle, and now I have a pretty drastic angle in the fretboard at the 13th fret where the neck meets the body. It falls away, towards the body, so no buzzing, BUT, the geometry is such that the actions a bit screwed up and the bridge is too high (lots of tension on the top, I'd imagine). So... my plan is to
1) carefully remove the neck
2) reset (sort of a backwards reset - since I want the peghead further up not further back)
3) reattach neck, so that the angle is correct
4) redress the frets
5) lower the bridge and saddle

So, here's my question -

My hypothesis is that due to my poor construction, the tone as well as the playability have been negatively affected - the tone isnt terrible, but it does have a pronounced "nasal and "harpsichordy" type of tone. I'm wondering if this is due to the bridge being overbuilt, (which it is, in order to support the high action) Any insight appreciated.

Corky Long

An overly large bridge could certainly restrict the bass range of the guitar and make it sound nasal. Do you have any photos you could post?

How long has it been strung up and playing? They will sound a little weird for the first hour or two.... I found my #1 took about 1 month with medium strings to really open up and sound good. That 1st hour.... that was a weird sound.

When you say too tall.... How high are the strings over the soundboard right in front of the bridge? Is it tall as in 5/8" or tall as in 3/4" right in front of the bridge? How high is your action?

Now, when you say Nasal and Harpsichordy.... what do you mean... like balanced too far treble (lacking bass) .. or kinda plinky sounding (very little sustain) or boingey like the sound of a Sitar or unbalanced (like 1 string playing stronger than another)....

Anyway, an extra-heavy-in-the-middle bridge can kill trebles and can make the guitar sound very bass heavy. Tone can also sound very very plain.

Thanks

John

I'd expect a heavy bridge to take away from the treble response, and make it _less_ 'harpsichordy'. Hmmm.

Walnut B&S tend to give a somewhat 'forward' and 'harsh' tone. It's a little hard to say why this should be: I tend to think it's due to the lower density and higher damping of the walnut, as compared with a rosewood. Maybe the light weight of the back gives it more 'punch' on the attack, and the higher damping cuts down on the higher overtones, which could help make the timbre more 'rich' when they're there. I dunno. I know I made a 000 in walnut/Red spruce some years back that had a similar sound to yours, if I read you right.

I built a walnut/Red spruce short scale classical a year or two after that 000. The hope was that the 'forwardness' of the wood combo would help make up for the lack of treble in the slacker nylon strings. It, too, was rather 'harsh'. One thing that helped was to tune the 'neck mode' so that it matched the 'main air' pitch. I'm hoping that the walnut/redwood classical I'm working on now will sound 'richer'.

Usually the 'neck' resonant mode (which is actually the whole thing vibrating like a xylophone bar) is too low in pitch to work with the 'main air'. In that case, due to the short neck and light headstock it was on the high side, so I ended up having to add weight to the headstock.

To find the 'neck' mode pitch, hold the guitar up by pinching the neck between your thumb and finger around the nut or first fret. This is a 'node' (stationary point) for this mode. Allowing the guitar to hang freely, tap on the back of the headstock with your finger tip, while listening with your ear close to the head. You should hear a fairly clear, low pitched tone. If it's within a semitone or so of the 'main air' pitch the two will couple usefully.

To hear the 'main air' pitch you can sing into the soundhole, with your face at least a soundhole diameter away from the hole. If you can't sing that low, try laying the guitar on your lap, pinching the low E string between your left thumb and finger at the nut end. When you pluck the string you should get a pitched 'thunk'. Move the pinch point up and down until you get the loudest 'thunk' when you pluck it: that's the 'main air' pitch. It's usually between F# and A.

If the neck mode pitch is low it's hard to raise it unless you can remove some weight from the headstock. If you've got sealed gear tuners with metal buttons you're in luck; replacing the buttons with wood ones will save about the weight of two machines.

When the 'neck' and 'main air' mode pitches are close enough to couple usefully they will trade some energy back and forth. This smooths out the 'main air' peak in the output spectrum, and gives you a little more low-end power, along with a more 'even' tone. This also seems to help with the 'harshness' in the mid-range.

Thanks John -

Good reminder on the "breakin" period - that may account for some of the strangeness of the sound. What I mean by the harpsichord sound is that the sound is a bit metallic, sustain isn't a problem - pretty long - but in general not a full, sound.

Here are the measurments:
At the bridge - jsut in front of the saddle
Low e string - 1/2" from string to soundboard
High e string - 7/16" from string to soundboard

At 12th fret - from string to fretboard (not fret top)
low e string - 3/16"
high e string - 1/8"

Alan -

Thanks for the info on neck resonant modes, and main air pitches. Do you conduct these mode "tests" while the guitar is strung? Or not? Or does it matter? Strung - the main air resonance sounds to me like an A and the neck resonance sounds like a B. Very interesting stuff. Thanks!