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View Full Version : What makes a guitar sustain?


Rich T Fingers
03-21-2005, 06:07 AM
I don't believe that there has been a definitive technical discussion on this key subject in these pages. I've seen sustain noted as being created by the ability of the strings to "ring on" without impedance from the body of the guitar which is why the Les Paul has a heavy body. However, the most sustaining guitar I have is a PRS CU24 trem with a WT (thin) neck so in theory it shouldn't sustain much. Moreover though, the next most sustaining guitar I have is a PRS Singlecut stoptail with a Brazilian neck like a tree trunk! Two totally different guitars that both sustain for days.
Clearly, individual guitars will embody factors that produce sustain outside of the ground rules.

But generally speaking, what are the ground rules : what in your opinion are the key factors that contribute to sustain?

Taller
03-21-2005, 08:47 AM
I think it's the luck of the draw actually. What you're describing is the sympathetic vibration of the body and neck as the strings vibrate.
Sometimes, the various pieces of wood simply work together as one.
Take the same guitar and put a different neck on it [same species of wood as the old neck] and it might not sustain as wonderfully as the original.

rooster
03-22-2005, 04:09 PM
Hmmm. Out of my guitars, the Heritage H150CM Classic definitely has the most sustain. The second place would be my USA Dean Caddy, third would be either the 1987 PRS Custom or the homemade flying V, with my Heritage H170CM next, and my strats trailing at the rear.

Tone_Terrific
03-22-2005, 11:42 PM
Seems to me that sympathetic vibrations can be a nuisance in that open strings start to ring too easily. I know, bad damping technique, but a nice even, equally distributed sustain over all the notes without a pronouced resonant hump would sure be nice (specially in a Strat)

rooster
03-23-2005, 12:16 AM
Yeah, but those imperfect resonances are what give each guitar its character. If you want to do without them, buy a Steinberger; they are "perfect" every night, but at the expense of the "cluck" of a Strat, the "chunk" of a Les Paul, or the "chirp" of an SG. My Heritage has that LP "chunk" and "honk" in spades, and I wouldn't trade it for the world. Now, if I could only play worth a crap....

rooster.

alderbody
03-23-2005, 08:10 AM
it's definately the wood type(density, weight, body and neck design) but i believe it's the materials the hardware is made of,
plus their design.

then it's also the nut, the string type-gauge and the pickup distance especially in single coil equipped guitars...

and luck of course, to get all those work right at the same time... :)

Rich T Fingers
03-23-2005, 12:11 PM
It's going to be all of those things, after all that is what a guitar is made of. However, what actual materials in what place? Sure, any materials can sometimes be in synch with each other but what, if you design it from the ground up, are the key factors - what wood in what place? Mahogany makes a great body wood but doesn't make a good fretboard for instance. But it's a technical question - what actually creates sustain? Sure any guitar can sustain well just because ... But I was interested in the technical answer, is it because the guitar itself does NOT impede the string resonance? And so is sustain all in the strings? Or do certain constructions using certain materials create or add to sustain?

alderbody
03-24-2005, 01:23 AM
Originally posted by Rich T Fingers
It's going to be all of those things, after all that is what a guitar is made of. However, what actual materials in what place? Sure, any materials can sometimes be in synch with each other but what, if you design it from the ground up, are the key factors - what wood in what place? Mahogany makes a great body wood but doesn't make a good fretboard for instance. But it's a technical question - what actually creates sustain? Sure any guitar can sustain well just because ... But I was interested in the technical answer, is it because the guitar itself does NOT impede the string resonance? And so is sustain all in the strings? Or do certain constructions using certain materials create or add to sustain?

In a "perfect" world with "perfect" materials, the sustain should be endless, because the strings should vibrate for ever.

But in this imperfect world we live in, there are certain rules that contribute to the loss of the amplitude of such a vibration,
and this has to do with the nature of the materials, the magnetic fields of the pickups, the friction between the surrounding air and the strings, and so many other factors that we practically ignore...

So what i believe is that the materials and designs in a guitar contribute to the amount of loss of the initial sustain,
but in an 'opposite manner' than we understand it.

This means that "better" materials/designs deduct less, and of course "worse" deduct more sustain...

The sustain is always "there", but also there are all those factors that kill it...

;)

Mark Robinson
03-24-2005, 12:12 PM
To me sustain is pretty much a function of how close you are and at what angle to the 4 x 12" cabinet you are. If there is a lack of sustain in your guitar, add a second 4 x 12" cabinet. Should take care of it easily.:D

Rich T Fingers
03-25-2005, 04:32 AM
Originally posted by Mark Robinson
To me sustain is pretty much a function of how close you are and at what angle to the 4 x 12" cabinet you are. If there is a lack of sustain in your guitar, add a second 4 x 12" cabinet. Should take care of it easily.:D

Mark, would I need to have the volume on number eleven?

Mark Robinson
03-26-2005, 01:01 AM
A non-master Marshall will give it up as low as two. It's just positioning and pressure. It's not too difficult to get feedback at low volumes. Fuzz units, compressors, some overdrives, or just giving the instrument a big exposure to radiating speakers, all will do it. Amps based on Marshall/Bassman circuits are sort of voiced for it IMHO. Also light guage strings and single coil pickups seem to help, also IMHo.

My reply was half tongue in cheek, but only half. A 4 X12" really accelerates the sustain of a guitar. All I'm trying to say is that sustain, to me, is way more about amplification, rather than what the guitar build is like. I'm no fan of excessively microphonic pickups though.

Rich T Fingers
03-26-2005, 05:45 AM
Originally posted by Mark Robinson

My reply was half tongue in cheek

I know, so was mine.... :cool:

John Phillips
03-26-2005, 09:39 AM
Alternatively, use a small amp with tons of gain, and you don't need the volume!

Actually I find heavy gauge strings and humbuckers work better - I can sit in front of my Mesa 1x12" with my PRS (with 11s), and get feedback at will at barely more than talking volume... even on stage, facing the other way, I don't need that much volume - which is a good thing, as I play in a band with a fairly 'delicate' female vocalist, and I don't want to drown her out.

It's the interaction between the strings, the pickups, the wood, the amp, and the speakers all together that does it. You do need a guitar that is inherently 'resonant' in the first place for the most even, controllable and 'musical' feedback though. Some combinations are much better than others, if the frequency responses and peaks line up in such a way as to exaggerate the closed loop. Also, if you're using a small amp, raise it up to the same height as your guitar body (but don't tilt it) - this increases the ease of getting feedback, and the control, really quite a lot.

I do actually like slightly microphonic pckups too - not excessively so, you need to be able to stop it if it starts to squeal - but I find it gives a lot more 'life' to the tone.

LavaMan
04-08-2005, 02:02 PM
Several factors affect guitar sustain:

- Type of wood - heavier/more dense the wood the more sustain - also size of the body affects sustain also

- Type of pickups - Humbuckers vs. Single coil - of the two humbuckers tend to have more sustain - EMGs are the industry leader for pure sustain

- Material used in neck - necks made of graphite composite or a combination of graphite composite and wood typically have more sustain

- Type of strings - certain strings have more resonance than others

- Type of Cable - run of the mill vs. high-end - better the cable the more responsive the amp - therefore more sustain

- The obvious: Amp choice - a good tube amp with nice gain channel or a clean good channel combined with a nice overdrive pedal directly affects sustain


These are just basic principles - you can get more technical detail than this on sustain....

rooster
04-10-2005, 04:32 AM
I have one in my case. I upgraded my pickups to Bill Lawrence 280S's, and no longer use it.

rooster.

Tube Guy
04-20-2005, 09:58 AM
Originally posted by John Phillips
Also, if you're using a small amp, raise it up to the same height as your guitar body (but don't tilt it) - this increases the ease of getting feedback, and the control, really quite a lot.
Hi John

Any particular reason not to tilt?

emjee
04-23-2005, 04:27 PM
yeah, Groove Tubes amp co. put 'em out, of all people.
If I could just find one guitar that sustains the same length of
time at all frets on all strings i would be ecstatic. Example: Hit
your Low E, and count how many seconds go by. Now hit the same string at the 9th fret. On my Hamer the open e lasts about ten seconds, and then when fretted at the 9th fret it only can be heard
for 4-5 seconds. Never tried a "Fathead", but Satriani sponsored them for awhile.

John Phillips
04-26-2005, 01:15 PM
Originally posted by Tube Guy
Any particular reason not to tilt?
Because it points the amp at your head.

I honestly think anyone who does this is nuts. Yes, I know it's quite popular :).

The biggest reason is simply that it totally distorts your perception of what the amp sounds like, or how loud it is. Pointed at your ears, it will sound far brighter and louder - so the temptation is to get a 'good tone' (actually for me that means really turning down the treble a long way, I hate the sound of a speaker pointed straight at me at short range), and set your volume about right for you - which means that for everyone else in the room, it will be too quiet and too muddy. If you're miked so much that the amp isn't really audible off the stage it's perhaps less of an issue, but it still doesn't tell you what the amp is really sounding like out front, unless the soundman mikes the center of the speaker and then leaves the EQ dead flat (which I've never, ever seen one do), and it's hard to put back missing top-end in a way that sounds good.

Equally, a small combo on the floor is no good either, you'll set the amp far too loud and bright to compensate for your ears being so far off-axis. All the experience I've had (I quite often go out front with a long cord at soundchecks if I can, and also take other people's opinions on my sound seriously) is that having the amp about waist-high and upright gives the best representation of the out-front tone and level when you're standing a few feet from it.

Secondly (the reason I mentioned it this thread) tilting it raises the volume you need in order to get controlled feedback, since the amp isn't pointing at the guitar any more.

I also think pointing a speaker straight at your ears like that is likely to be worse for your hearing, even compared to slightly louder and not directly at them - although I don't have any factual evidence, just the perception I get when the monitors are too loud (I also hate having my guitar in them for all these reasons).

There's also a small possibility that tilting the amp may be bad for it - some (though few) tube types don't like being operated off vertical, and on most combos it will also allow heat to build up under the chassis, where the hot air will more easily become trapped.


How many pro touring bands do you see with the amps tilted? ;)

Tube Guy
04-26-2005, 03:45 PM
Thanks John - I'll take that as a DON'T TILT then :)

I saw Dr Robert at a Gibson guitar clinic a few months and his first advice to everyone was the same as yours, get a combo up to waste level pointing at your guitar.

He went on to suggest that the EQ should then be set to maximise the sustain from the guitar in that particular venue. (I think I'm quoting him correctly there).

AJ Love
05-16-2005, 10:52 AM
there is natural sustain coming from a guitar acoustically and then there is electric sustain coming from the right pickups/amp etc...ideally both is happening

in my experience, you need to play an electric guitar unplugged first to see whats going on with it... a solid dense wood like Alder will give a good sustain, especially if it is joined with the right maple neck

nmw01223
12-12-2008, 07:23 AM
This is an old, old thread, but I thought I might as well add my views. I'm an engineer so probably come at it from a different direction to most.

Sustain is about energy - not losing it. When you pluck a string, you put kinetic energy (movement) into it. Over time that energy is lost from the string (ends up as heat) hopefully producing a bit of sound along the way.

So where does it go? Basically, it is lost by 'damping' - in the string itself, the material the guitar is made of, the magnetic field from the pickups, even air. Damping just means energy loss in this case, mainly to heat (tiny amount) - you never actually lose the energy, it just moves on elsewhere.

How do you hang on to it? Firstly it is a tiny amount of energy, and it doesn't take much to lose it. Don't let it go anywhere. A guitar body - wood is really quite soft - will absorb energy fast. Something like a metal body, or rigid plastic would probably do so much less (there would be other penalties, like resonance). So, the heavier and stiffer the body, the less it will flex, and thus absorb energy. Probably why Les Pauls sustain such a lot. It is also the wood type. Harder woods damp less - balsa or cork would be hopeless(!), mahogany is pretty tough stuff. One would assume the neck is more key than the body - it is after all much thinner and less supported (more flex). You can't do much about the air except play in a vacuum, but the pickup magnetic field dampens the strings. The closer they are and the stronger the field, the more damping due to eddy currents. If one was to 'short' the string by connecting it electrically from one end to the other, thus making a loop, I suspect it would damp very fast. One would imagine the string material would also have an effect, but probably dwarfed by the other effects.

It doesn't necessarily follow that a non-flexing rigid body and neck (like a piece of granite) would sustain the most. Yes, the body wouldn't lose energy (never got any in the first place), but actually, when the string is plucked, the string AND body flexes so the player is putting energy into both. More energy therefore than just into the string. So it may damp more, but there is a lot more to lose. So the combination of a light body and neck of a low damping material can have good sustain.

Logically one would expect an acoustic to sustain less - after all, it is radiating that energy away as sound, but of course, the pluck puts significant energy into the (non-rigid) body, therefore more energy is entered in the first place. Also light strings - less energy in the string in the first place. Basses do seem to ring for ever.

Sustain is a passive process - you put energy into the instrument, and would like it to hang around as long as possible. But, then there's active sustain. The strings vibrate, the pickups produce signals, the amplifier makes them bigger and the speaker cone moves. That moves air, which vibrates the instrument and string, and ... off it all goes again. It is called a feedback loop. If the loop gain is bigger than 1 (more energy is available at the end of the loop than the beginning), it oscillates at some resonant frequency, and that is the howl you get when too close to the speaker. The trick is therefore to place yourself such that the loop gain is just less than 1 - creates lots of active sustain, but doesn't actually oscillate out of control. The sustainer guitars do exactly the same thing, except that they drive the strings directly.

Where else does sustain go? Bad woolly fingering. That's where all mine goes. The wood is quite irrelevant.

curtis
12-13-2008, 12:37 AM
- what he said.

a good clean mechanical connection between the string and the nut, and string and bridge will make one guitar sustain longer than another of same type.

Wood etc is a factor ( the more solid the bridge due to its foundation, the more energy reflected) but by far the largest part is the point where the strings energy is reflected back up itself to the other end, where it is reflected again etc etc. thas why a properly cut nut and bridge is soo important.

generally it seems to me that guitars with more sustain have less character, and vice versa. personally i like character, set it up properly and you have a good instrument.

cheers,
steve

slartibartfast
12-17-2008, 07:28 AM
What I think everybody forgets is the amp. Everybody goes on about the strings driving the body and the neck, and I agree until you plug it into an amp. The amp will drive the body and the strings on a light guitar and make it sustain. The amount of energy that a string can supply to a solid body is tiny compared to what an amp can. For ultimate unplugged sustain, the heavier the better (the tone will be a dud though). The energy radiating from an amp will have a harder time driving a heavy guitar than a light one though, and you wont get as much sustain.
Its a big circle. The strings drive the body and neck, the resultant vibration is converted to a tiny pulse of A.C. The electricity is greatly amplified and turned into sound energy by the amp. The sound energy coming out of the amp drives the string and guitar

TooManyHobbies
12-17-2008, 01:30 PM
yeah, Groove Tubes amp co. put 'em out, of all people.
If I could just find one guitar that sustains the same length of
time at all frets on all strings i would be ecstatic. Example: Hit
your Low E, and count how many seconds go by. Now hit the same string at the 9th fret. On my Hamer the open e lasts about ten seconds, and then when fretted at the 9th fret it only can be heard
for 4-5 seconds. Never tried a "Fathead", but Satriani sponsored them for awhile.

They work.. quite well. I sadly never bought one back in '96 or so when I first saw them, the ones which were originally made were fit to the entire back of the headstock. The newer ones simply clip on. The newer ones do work.. but what I've found is that they're simply increasing headstock mass.

I have considered drilling holes in the headstock and filling them with bell brass rods for a similar effect. I think that you'll find that heavy tuners and a CBS headstock fender with sustain more, and more evenly than a small headstock with light tuners.

JZWest
12-17-2008, 04:15 PM
They work.. quite well. I sadly never bought one back in '96 or so when I first saw them, the ones which were originally made were fit to the entire back of the headstock. The newer ones simply clip on. The newer ones do work.. but what I've found is that they're simply increasing headstock mass.

I have considered drilling holes in the headstock and filling them with bell brass rods for a similar effect. I think that you'll find that heavy tuners and a CBS headstock fender with sustain more, and more evenly than a small headstock with light tuners.

be careful what you ask for. as you change the ratio of metal to wood so will change the complexity of the tone. but then again, one may wish to lean towards a more metallic and fundamental tone vs a warm, complex and woody tone

TooManyHobbies
12-17-2008, 04:37 PM
be careful what you ask for. as you change the ratio of metal to wood so will change the complexity of the tone. but then again, one may wish to lean towards a more metallic and fundamental tone vs a warm, complex and woody tone

Absolutely, which is the reason I haven't tried it yet. The fathead (and now fatfinger) I would recommend without question, but the drilling of the rods always made me nervous.

BarryW
12-17-2008, 05:08 PM
The harmonic vibrations of the woods, how they are joined to each other, and to the universe.

And your fingers.

;')

shane88
12-17-2008, 06:22 PM
play loud ;)

khromo231
12-18-2008, 02:31 PM
We should distinguish between mechanical sustain and feedback. The greatest enemy of mechanical sustain is probably absorption of the energy in the vibrating string by the instrument, through shaky hardware, resonance, etc.

If you suspend a string between a mountain and a skyscraper, your mechanical sustain would be maximized because neither the mountain nor the skyscraper would sympathetically vibrate, bleeding energy off the string. That was the theory behind many of the boat anchors built in the early seventies. A lot of those instruments were "overly engineered" and not very musical sounding because the science part of building a great sounding instrument is sometimes at odds with the "art" part of building a great instrument.

All of this is my opinion and experience. I don't want to get in a war with any Guitar Scientists! I just want to build good sounding musical instruments.

Tone_Terrific
12-18-2008, 05:17 PM
Anyone who direct records moves the acoustic feedback aspect right out of the equation. Sustain and the whole shape of the decay envelope, with it's complex overtones, starts with the guitar.

walterw
12-19-2008, 04:53 PM
when the string is plucked, the string AND body flexes so the player is putting energy into both. More energy therefore than just into the string. So it may damp more, but there is a lot more to lose. So the combination of a light body and neck of a low damping material can have good sustain.
now this is an angle i've never heard of before, that you can put energy into the body as well as the strings with your initial pluck, basically "storing" more than can be stored in the string by itself.

it jibes with my unscientific impression that the best guitars in terms of sustain and tone have stiff, fat necks and light, resonant bodies.

jalguitarman
12-19-2008, 11:13 PM
OK I this is a good time to clarify a term here. I think i know what this means but i want to make sure i have this complete. I mean I understand it but never have put words to it. When we say something is resonant. Like saying a lightwieght 57 strat is resonant. Your saying that it transfers vibration well, correct? If a guitar is resonant it transfers vibration well?

walterw
12-20-2008, 02:27 AM
OK I this is a good time to clarify a term here. I think i know what this means but i want to make sure i have this complete. I mean I understand it but never have put words to it. When we say something is resonant. Like saying a lightwieght 57 strat is resonant. Your saying that it transfers vibration well, correct? If a guitar is resonant it transfers vibration well?
i take it to mean that the vibrating strings cause the body to vibrate as well. the ultimately "resonant" guitar is an acoustic guitar.

Sleepy
12-21-2008, 02:19 PM
I would think it has to do with the absorption rate of materials connected to the strings

for example;
if you placed a towel in between the bridge and the body of the guitar the towel would quickly absorb the resonance of the string.

considering this
If a guitars body did not resonate the strings would most probably resonate longer.
it takes energy to resonate the body of the guitar..... that energy has to come from a source (the string vibration)
since we like the body of the instrument to vibrate, I think there is your trade off.

Norse
12-21-2008, 02:40 PM
Another source of sustain has to to with the mechanical break angle of the strings over the nut and bridge. I once read a local luthier (Arroyo Grande, CA. U.S.A.) explain how 17* is the optimum angle, allowing storage of energy to be released back into the string after being plucked.

Tone_Terrific
12-21-2008, 04:04 PM
Another source of sustain has to to with the mechanical break angle of the strings over the nut and bridge. I once read a local luthier (Arroyo Grande, CA. U.S.A.) explain how 17* is the optimum angle, allowing storage of energy to be released back into the string after being plucked.

Consider Floyd's...zero break over the nut. You can back off the main tuners to verify.
Consider wraparound tailpieces....zero breakover, no body anchor except through the posts.
Consider acoustics...very resonant, but the resonance must be tuned to be evenly balanced and yet notoriously short sustain.

With electrics we are lucky that wood and SO many other materials can work as end points for the strings. All materials will have some resonance.

I like a guitar that does not emphasize any particular tonal band, whether that makes the guitar louder, quieter or whatever, acoustically is not the prime issue.

How to do that...I don't know.
One might expect that the big companies have analyzed the whole construction model, but they are not telling if they have, and most of the products are just aimed at the good-enough-to-keep-selling end of the market with vintage 'mojo' being sold ahead of performance enhancements.

I rant:drink