"Acoustic resonance on an electric guitar"

[Esquire Rod]

When choosing a guitar or simply judging one, does Acoustic Resonance, meaning how loud and how long notes ring out when the guitar is unplugged, is this the really best way to determine if any particular guitar is better than any other?

 

[Boreas]

Certainly not the BEST way unless you are looking for a guitar specifically for acoustic qualities. You could have a great-sounding guitar acoustically, but if it has crap pickups and other hardware, it could be a wet dog when plugged in.

 

[OldTelePlayer]

Its one of several "tests" I use. Associated with "acoustic resonance" is feeling the guitar body's vibrations when playing it... I'm holding it against me and as I pluck strings I should feel the guitar body vibrate a bit. Of course, the neck, pickups, construction quality and other hardware also figure pretty large in the evaluation. Also, an evaluation of a semi-hollow or hollow body electric has other items related only to those that I look at.

 

[mexicanyella]

I’ve encountered different ideas of just what “acoustic resonance” means, but my opinion is this: I have a guitar that sounds dead and inert unplugged, and another one that seems resonant and bright and zingy.

Both of them make useful sounds plugged in, and the first one doesn’t seem dead through an amp.

But the zingy one feels alive to me and is more fun to play, and is usually what I reach for.

 

[mandoloony]

I don't care how an electric guitar sounds unplugged, but the acoustic properties certainly affect the overall sound of the guitar through an amp. The attack, sustain and overall tone are heavily affected by the whole instrument, not just the pickups. You can't separate the acoustic nature of the instrument from what you hear coming from the amp.

 

[Tricone]

Resonance is one of a couple tests I do. I consider it the most important along with how well it plays.

 

[TimTam]

Its one of several "tests" I use. Associated with "acoustic resonance" is feeling the guitar body's vibrations when playing it... I'm holding it against me and as I pluck strings I should feel the guitar body vibrate a bit. Of course, the neck, pickups, construction quality and other hardware also figure pretty large in the evaluation. Also, an evaluation of a semi-hollow or hollow body electric has other items related only to those that I look at.

This highlights the contradictory nature of some peoples' notion of resonance in solid-body electric guitars. The vibration energy to vibrate the solid body must come from somewhere. If it comes from the strings, then the strings are vibrating less (Conservation of Energy Law). How that could possibly be a "good" thing is hard to discern.

A truly "resonant" solid-body guitar is one where string vibrations remain overwhelmingly in the strings. With minimal losses to vibrate any other structures. Guitars are "subtractive" (a notion that Paul Reed Smith gets right).

When you strum a solid-body guitar and it really "rings" acoustically, that's acoustic sound waves from the strings you're hearing, not the body. As such, the acoustic sound does have some relevance to the performance of the guitar, as string vibrations are obviously what pickups "see". Of course other things also affect whether all those string vibrations are transduced through to the guitar's output, and how (eg pickup resonant frequency and Q factor).

So there is no guarantee of a close correlation between the acoustic sound and the guitar's output. For example you can have a guitar that has an prominent attack acoustically (because all those high transient frequencies are there in the strings of most guitars), but it might have a dull attack at its output (eg because of a pickup's low resonant frequency - change the pickup and the attack comes back ... because it was there all along ... in the strings).

 

[pypa]

I'm no pro, but I've made and handled enough guitars that for me the things that tell me it's made well are the stability and feel of the neck and the relationship of the fretboard to the bridge. The electronics can always be swapped out or upgraded (albeit at possible considerable cost), but the "geometry" cannot be easily fixed. This affects playability and adjustability, which are WAY more important to me than the acoustic properties of alder vs ash (which to my ears are masked entirely by the quality of the electronics).

So my order of importance is:

1) neck geometry and feel
2) electronics quality
3) aesthetics
4) acoustic properties of the body.

 

[mandoloony]

A truly "resonant" solid-body guitar is one where string vibrations remain overwhelmingly in the strings. With minimal losses to vibrate any other structures. Guitars are "subtractive" (a notion that Paul Reed Smith gets right).

This is false. It is not possible for energy to remain "in the strings" unless they are not coupled to a body. You cannot get a standing wave in the strings without those vibrations reflecting through the body.

When you strum a solid-body guitar and it really "rings" acoustically, that's acoustic sound waves from the strings you're hearing, not the body.

Again, false. When you strum a solid-body guitar and it really "rings" acoustically, it's because the body is vibrating. The strings have so little surface area that their vibrations alone create almost no audible sound.

 

[Esquire Rod]

One of the reasons I posted this question is because I recently changed strings to some Stringjoy boutique strings and immediately noticed that it was louder acoustically. Which was nice as they cost a bit more and I often play unplugged.

Guitars are full of wives' tails and rumors all components in the signal chain contribute and can be swapped out. I
don't have a hard and fast stance on the issue but find it interesting how people quantify what makes up a better instrument.

 

[Jakedog]

This is false. It is not possible for energy to remain "in the strings" unless they are not coupled to a body. You cannot get a standing wave in the strings without those vibrations reflecting through the body.


Again, false. When you strum a solid-body guitar and it really "rings" acoustically, it's because the body is vibrating. The strings have so little surface area that their vibrations alone create almost no audible sound.

Disagree. He’s got it right. While it’s true that all the energy cannot stay on the string, the more that stays there and does not transfer the better. When you pluck a string, it vibrates. Anything else that vibrates is the result of energy transferring FROM the string TO another material. How much it transfers will subtract from how long and how loud that string will vibrate. That’s just basic physics.

 

[mandoloony]

How much it transfers will subtract from how long and how loud that string will vibrate. That’s just basic physics.

Almost all of the energy is transferred to the body. How much is reflected back will determine how long and how "loud" that string will vibrate. If the energy remained in the strings, you would hear almost nothing. That's just basic physics.

 

[Dostradamas]

Awe fiddle stix

 

[Killing Floor]

There should be an option between B and C. The body of an electric guitar does 3 tasks. It holds the pickups in position, opposes the tension of the strings (along with the neck obviously) and it is the primary damper in the spring-damper system while also contributing some spring like properties. To that end, how the body acts to decay the vibration affects output. It doesn’t affect tone, that’s where the paint comes in because we hear with our eyes. But wood that dampens slower means a note rings longer.

The more esoteric issue is the overtones you hear unplugged don’t necessarily contribute to the flux that the pickup detects.

 

[Hodgo88]

Frankly, I don’t care how my electric guitar sounds until it’s plugged into my gear.

In fact, a lot of my growth as a musician in the last 5 years has been walking away from putting anything (theory, gear, technique, cleverness) ahead of the end result - the sound. These days the only rule is that if it sounds good, it sounds good.

 

[jvin248]

.

I always find this 'liveliest guitar' pondering humorous.

The cheapest guitars are routed with a swimming pool route, use hard ABS single-ply pickguards, and Agathis/Paulownia body wood.

Meanwhile the most expensive guitars are built with pickups that just fit in pockets in the body, use triple-ply soft vinyl pickguards, and more rigid lumber like Ash.

The cheap guitars often act more like semi-hollow guitars for their acoustic properties unplugged. But they are cheap and the expensive guitar buyers would never touch them for fear of cooties, yet they search for more lively versions of their designed-to-be-dead instruments.

Remember that Les Paul and Leo Fender both designed their guitars to cut out as much vibration and potential feedback as possible. They wanted acoustically dead guitars to protect against feedback and use their amps in large and small bands.

If you are really serious about a lively guitar ... find a cheap one

.

 

[KokoTele]

This is false. It is not possible for energy to remain "in the strings" unless they are not coupled to a body. You cannot get a standing wave in the strings without those vibrations reflecting through the body.


Again, false. When you strum a solid-body guitar and it really "rings" acoustically, it's because the body is vibrating. The strings have so little surface area that their vibrations alone create almost no audible sound.

This isn't right, but TimTam's not quite right either.

When a wave (the string, in this case) meets an anchor point, some part of that wave is reflected back into the string, and some part of it is transferred to the anchor point. (Vibrations don't reflect through a body. They either reflect or they transfer through it.)

So, the wave hits the saddle and some of it goes back into the string (which is why it keeps vibrating) and some is transferred through the saddle into the body. (If this weren't the case, a piezo element under a saddle wouldn't work.)

Some hunks of wood resonate well at frequencies that match what comes from the string. Some create more damping force at those frequencies than they create resonance.

The strings have so little surface area that their vibrations alone create almost no audible sound.

Nuh-uh. If this were the case, you'd never hear the twang of a rubber band stretched between your fingers. While the strings have relatively little surface area, they have plenty of amplitude to move some air and you can hear the sound.

If we relied solely on the body for the resonance, you could never hold a guitar against your body or the notes would die out immediately.

Back to the original question: you can make cool sounding electric guitars out of almost anything and they don't necessarily need to resonate. Try playing an ES-335 acoustically. Might as well be made of plastic. But most sound pretty awesome when plugged in.

Danelectro made some pretty awesome sounding guitars out of masonite.

Is it just the pickups? No, of course not. There are a thousand different elements that create the tone and character of a guitar.

Anyone remember Greenwich Village Custom Guitars? He was one of the early builders who made replicas of vintage Fenders, and to most people they were the best relics available. I had custody of an awesome one for a while. It was a featherweight ash one that was about 6 1/2 pounds. Rang like a bell when played acoustically. It was easily the loudest solidbody electric I'd ever touched. Incredible note separation, tons of overtones... It sounded a lot like an OM-bodied acoustic, just quieter.

However, when played at stage volume it totally turned to mush. No definition at all. Sounded dull and flat, and the only good tone was with a lot of overdrive. But with that much overdrive a broomstick sounds pretty good too. The pickups were a set of custom wound Lollars that were similar to his standard Tele pickups. In most Teles, those pickups would have sounded incredible.

 

[mandoloony]

Nuh-uh. If this were the case, you'd never hear the twang of a rubber band stretched between your fingers. While the strings have relatively little surface area, they have plenty of amplitude to move some air and you can hear the sound.

A rubber band has much more surface area than a string, and the noise it makes is minimal compared with any solidbody guitar. The noise you get from a vibrating string is far less than from a rubber band.

This isn't rocket science, and easy to test if you have a spare string available.

 

[schmee]

It is in my book. Every time. The first test to find a keeper is playing it unplugged, if it's dead wood unplugged I ain't buyng it.
Unless you are playing real loud, like in front of a Marshall stack, then it matters little other than avoiding feedback.
But the real test is not a video of guitar strings and a pickup between a bench and something else. It's playing a guitar or amp for a set or more, in a band mix, on stage, on various songs. Because that's how the subleties come out. It's all about subtle things, other than that a guitar is a guitar.
Pickups change a guitar in a minor way only.

 

[Freeman Keller]

I spend a lot of time futzing with the acoustic tone of an acoustic guitar when I build it, I tap the wood and measure the time and frequency responses, altho frankly I'm still struggling with what I am hearing and how to control it. When I build an electric guitar that is the last thing I worry about, they sound however they are going to sound that that's all I care about. I rarely sit around playing a solid body electric guitar unplugged because frankly they sound like crap and none of my acoustics have magnetic pickups so it is a moot point for them.