Doper guitarists: help me get my head around the physics of electric guitar

Specifically, tell me how in the world body woods make any difference at all to the tone of an electric guitar. This is an issue which has bothered me for years. I always hear about “superior tonewoods this” and “old-growth mahogany that” and “rock maple tone whatsit.” The whole issue confuses me.

Aren’t electric guitars basically just a set of steel strings vibrating in a magnetic field created by the pickups? Why would the type of wood associated with the electrical system make any difference at all? I’m not doubting that influences it a little, but 1) I’m not sure how much of it is just me wanting to think it’s important, and 2) I have no idea why it would influence the sound.

So, does anybody have the straight dope on this? As in, do you know of any specific physical phenomena which might explain it? I’m not really looking for responses along the lines of “I dunno, but I know it does, and that’s all that matters.” I’d really like a coherent explanation, if anybody has one.

The one possibility that occurs to me is that the type of wood may influence the way in which the strings vibrate, but I’m damned if I know how that would work specifically, and frankly, that just sounds like more linguistic legerdemain to avoid providing a specific explanation.

Feel free to get as technical and mathematical as you think necessary. I grok fairly high-level math.

In my 20 years of playing, I’ve noted essentially two schools of thought. First, there’re the self-professed tone freaks and “guitar snobs” (for lack of a less demeaning term.) These are the guys who only play vintage Gibson LP’s made from old-growth mahogany which no longer exists in the wild, or old-school one-piece Paul Reed Smiths, etc. Then there are the guys (who can be lifelong guitar players and extremely proficient) who shrug and say “Fuck it. Bolt-on Mosrites are fine. Get good pickups and a good amp, and you’re golden.”

So which is it, and why?

The wood will affect the acoustic sound of the stings, so its important if your going to use piezoelectric p’ups. But for regular p’ups the amp, p’ups, type of construction (bolt-on, set, through neck, &c.), and effects are gonna be more important than the wood itself.

As for the physical phenomena I would imagine the sting vibrates, trasfers that vibration to the wood, it resonates back though the wood into the stings. But IMO you really can’t hear that fine of a tone distiction over the tone of the pickups themselves.

The pickups get sound from the body as well as the strings and he density and specific compositional properties of the wood affect the vibration of the strings and the overall tone.

Not doubting you, but how do the pickups get sound from the body? Wood is a nonmagnetic medium. How would it generate an electric current?

The wood resonating in turn resonates the strings, I’ve always thought that it’s a feedback loop of sorts. You can definitely tell the difference between an archtop and a solid body.

Now that’s a fair point. However, is the difference really the body structure? Aren’t hollow-bodies usually modeled after older hollowbody electrics, which were developed with somewhat microphonic pickups?

I suppose that’s another complicating factor. A microphonic pickup will most definitely, without question, be influenced by the type of wood, because it’s picking up sound waves actually generated by the wood. But will a “tight” pickup act the same way in a hollowbody? I don’t know. To my knowledge, I’ve never heard a modern pickup in an older-style guitar.

I will say this, however. I put a set of modern, tight DiMarzio’s (mid-output humbuckers) in a 335 copy I have, and for my money, it sounds just like a solid-body rocker. shrug

The current hollow body guitars are modeled after the original arch top acoustic guitars like the Gibson Super-400 or the L-5 (there’s a bunch of L’s but the L-5 is the best of the group). These guitars had carved tops and f-holes as the sole means to amplify the sound. Once a usable pick-up was invented in the thirties they were added to that design. Charlie Christian played one of the first usable electric guitars, the Gibson EH150 (oddly enough the lap steel guitar of the same name was essentially the first solid body guitar that depended solely on a pick-up for the sound). Before that the guitar was simply not loud enough to do much but provide a faint pulse of rhythm in the background(banjos worked a lot better). It wasn’t until the late thirties that you start to hear guitar solos (you can barely hear the guitar on most recordings before that) when the guitar is playing with a band.

As others have said, wood is a significant factor in a guitar’s tone: the kind of wood determines how the strings vibrate, and those vibrations are captured by the pickup’s magnetic field and transferred by the pickup into an electronic signal.

So, for example, an all-mahogany Les Paul (e.g., Les Paul Special or Junior) will sound different from a Les Paul with a maple cap: the maple cap produces a brighter, more articulate tone, whereas the all-mahogany body produces a somewhat lower point of resonance, giving the guitar a “chunkier” tone.

The kind of neck-design affects the tone similarly: bolt-on necks sound different than glued-on necks, as each design affects how the strings vibrate in unique ways. The kind of wood used for the neck—and even the fingerboard—affects the tone of a guitar. For example, some players prefer Stratocasters with rosewood necks because they produce a slightly warmer tone, whereas some players prefer all-maple necks on their Strats because they produce a snappier tone with a more immediate attack.

These aren’t imagined differences—they’re very real, and immediately discernible when you play these guitars/wood-combinations side-by-side.

I also don’t think you can compare a 335 or similar models to a super 400 that has a huge, deep body as well as an intact carved spruce soundboard (no holes for pick-ups or knobs). These guitars they usually have a neck mounted humbucker or some other floating bridge solution.

The current produced is due to the relative motion of the string and pickup - obviously the motion of the strings is the major factor, but any vibrations within the body (and therefore of the pickup relative to the strings) will also affect the overall output.

There is a lot of B.S. about solid body woods,much of which can’t be proven.
On the other hand there isn’t much dispute that the denser the wood,the greater the sustain.Much as Subterraneanus notes by citing a maple capped Les Paul.A guitar that will droop your shoulders.
I’m not convinced about neck attachment,though through-the body styles do seem to have an edge.
An ES-335 is really a solid body in arch top attire-it has a solid maple (OK laminated) block between back and top which eliminates feedback (and how else could you have a stud tailpiece?).Compare it to a 330,which is an arch-top,albeit molded plywood vs. carved spruce.Otherwise identical.
There is no comparison to true arch tops.They were made to project over the rhythm section and did it well,but their playing requires musculature to “force” the top,which is why most such guitarists using the axe traditionally will pick every note-Charlie Christian being a good example.
There’s a fair bit of disagreement about the purpose of f-holes. I subscribe to the idea that they keep the guitar from destroying itself from wood movement.

I can’t believe there’s a “guitar tone” thread and WordMan hasn’t posted yet. He must be sick or out of town or something.

Paging WordMan!

The wood affects how the string vibrates. The vibration of the string is picked up–hah!–by the electromagnetic pickup. If the wood is denser, less of the vibration is soaked up by the wood and thus the string sustains longer, and may have tonal characteristics affected by the frequencies being absorbed by the wood.

Now, I don’t believe the “wood feeds vibration back into the string” theory. There’s no excitation from the wood to add energy to the system (unless you pound your fist on the body of your guitar, which I have been known to do on occasion). However, the amplifier certainly adds energy, so feedback can come from the amp/speaker back into the guitar and that can certainly affect the sound. A hollow-body can resonate more to the sound that’s in the air and that will affect how the strings vibrate. There may be more subtle effects from different types of wood in a solid body.

All that said, I’m in the “shrug and say ‘Fuck it’” school. If the guitar sounds good thru the amp, and feels good in my hand, I’m playing it.