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hey, just a few questions on guitars opening up.
i haven't had much experience here,
but did notice on my last build, after first stringing it up,
the bottom 4 strings and top 2 strings sounded like they were played on 2 different gits.
after a week, that changed, and it sounded more "balanced".
so, one question is, what kinds of wood open up differently from one another,
or quicker, and what usually happens when they do.
more bass, more treble, more balance, more focus?
sorry for the "buzz words"!
what are yer experiences?

I don't know about steel strings so much, but in classicals, Spruce seems to open up more than Cedar. Spruce tends, in my brief experience, to open up more in the bass and mids, while I have not heard as much change in the trebles. It also matures a bit, and seems to project better, but that may be due to the opening up of the bass and mids. The treble is very directional anyway.

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Waddy

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Sound Clips of most of my guitars

Nobody is quite sure what happens in the gutiar when it opens up, but the outcome is always the same: the top gets looser. The 'main top' resonant mode can drop a bit in pitch (often by as much as 1/2 semitone), and it becomes more active. Since the top is moving more air, the 'main air' resonance also becomes stronger, usually.

These are the two lowest pitched resonances that can produce sound, so you'd expect the bass to get stronger. Generally it does. However, since the 'main top' resonance works like a loudspeaker cone, with trhe entire lower bout moving in and out, it's the most effective sound producing mechanism on the guitat, and it has a long 'tail'. It's been found in computer studies that making the 'main top' resonance more active can increase the output all the way up to 1000 Hz, the pitch of the note you get from the 20th fret on the high E string.

Another thing that often happens is that the 'main top' peak in the output spectum becomes broader, which I asociate with a 'fuller' sound.

It's interesting to note that the wods that seem to 'play in' the least are Western red cedar and Redwood, both of which tend to be splitty. I haven't tried Doug fir on a guitar yet; that's another splitty one, and I wonder if it acts the same way. If so, it might suggest some things about what's happening when the instrument plays in.

I offered my views in the current tonerite thread.

http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=28635

Cheers

Kim

I find that the initial curve of "opening" with spruce is very steep and then levels off. I was playing a brand new build for my wife and swapping it out with an older guitar while she was not looking to get her observations. (She is great by the way). At one point in the space of about ten seconds the new guitar REALLY changed. My wife thought that I had changed guitars. It was really quite amazing. I did not observe much more changing after that.

Concurrently I had a cedar build in the white. I strung it up and played it and was a little disappointed with it at the time. I played it for a day or two but it did not do a lot of changing. I got a couple of orders in and since the cedar build was speculative ( and disappointing) I put it aside in a guitar stand on my workbench near the stereo and did not touch it for weeks. When I got back to the cedar guitar to start the finish I played it and it was completely open and alive. All it had done was sit around the shop for a while but it changed a lot over a period of time.

I am also willing to bet that just as with everything else there is no hard and fast rule that works and that each guitar will react differently and in its own time.

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http://www.booneguitars.com
https://www.facebook.com/pages/Stephen-Boone-guitar-builder/488208541257210

Ummm Stephen sorry but you loose the bet ...you see... the hard and fast rule is
"each guitar will react differently and in its own time."

So now what?

blessings
Padma

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Audiences and dispensations on Thursdays ~ by appointment only.


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thanks for the input.
very interesting stuff here.
somebody told me maple takes longer, koa takes longer, mahog takes shorter.
i don't know, i just play certain ones more,
for some reason.
i like da maple back and sides, cheap spruce sitka top.
wide grain, almost quartered.

I find I generally like cedar better when New. Under five years approximately.
I find I generally like spruce better when Old. Past five years approximately.

Don't know what this means but this is my general impression.

I believe Cedar opens up fast in the first two years and then levels off.
I believe Spruce opens up slowly but probably continues to improve / open up, for centuries.

I have played a Antonio Torres, can't remember the year pre-1900, a Santos Hernandez 1928, a Domingo Esteso 1923, Vicente Aria 1909.
All were spruce and all had a liveliness and a eagerness to respond to the lightest touch.
They were all quite intoxicating to play.
I have a 1969 Manuel Velazquez that is already exhibiting these qualities.
Not to the extend of the older guitars mentioned, but getting there.
Maybe in another 50 years It will get there.
Too bad I won't be around to enjoy it ;-(

Oh yeah, one more thing.
They were all build like a feather.
At first It made me nervous.
I felt like they could explode or I could crush them with my bare hands If I was not careful.

I think I read somewhere that wood actually loses weight over time.
Maybe Alan knows about this?
Could it be that these old instruments were not as light when new, as they are now - uhmmmm???

They may not have been, but when you look at Torres top thicknesses, they are often as thin as 1.4 to 1.5 mm at the edges. Backs were, often, also very active on many of those guitars, which is another indicator of lightness vs thicker. I think, too, because of construction techniques and hand bending processes, sides were often thinner than on many guitars today where the maker uses a bending form. I have played a Vincente Arias, and it was very light as I recall. It was a number of years ago and I don't recall the year of construction.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

I've read that the structural part of wood consists of three main things: cellulose fibers, lignin 'glue', and hemicellulose 'filler'. The cellulose accounts for about half the structural weight, with the other two being about equal parts of the remainder.

Hemicellulose is a branched-chain polysaccaride: sort of a random conglomeration of modified sugar units. It has lots of 'loose ends', as it were, which, among other things, pick up water from the air. Over time these sugar units break down into H2O and CO2, with miosture cycling speeding that up, iirc. The article I read said that the wood looses about 1%/decade, but whether that was 1% of the total weight of the wood, or 1% of the hemicellulose (which seems more likely to me), was not clear.

So, yes, the wood does get lighter with age, but not a lot lighter over the course of a few decades. It also loses some strength, but the decline in weight is said to be faster than the decline in Young's modulus, so the stiffness/weight ratio rises a bit.

Hemicellulose seems to be the only part of the wood that absorbs much moisture, so as it goes away the wood becomes more stable. It's possible that some of the 'baking' and 'stewing' processes that people use to artificially age wood also bind up the loose ends, so to speak, so that even if there's some hemicellulose left, it's less likely to abslrb moisture. It's hard to say without data.

As the hemicellulose dissappears it leaves behind holes in the wood structure, and these make the wood more opaque. It's like all the air spaces in between the transparent snowflakes that make the snow bank white.

I've noticed even old guitars opening up after sitting without string tension for long periods of time. Some of them exhibit the same sort of tightness as new guitars, though to a lesser degree, changing more quickly and settling in more quickly too. So it seems to me there could be something else going on along with the molecular changes.

Pat

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formerly known around here as burbank
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http://www.patfosterguitars.com

I have noticed that too in guitars that have sat for a couple of years without playing. They sound very stiff, and the response is slow. They adjust more rapidly, though, than breaking in originally, it seems.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Some sensitive guitars take several days to recover its original sound if the strings were all took off when changing strings.

cool observations.
tone monkey stuff.

I've noticed that in making different stringed instruments, that when parts of the instrument were subjected to minimal stress in assembly, they took less time to break in, or open up. A lot also depends on not fracturing fibers in bending, and having to "urge" sides into conformance of shape. Depending on the amount of total stress added into a finished instrument, the results of time needed for an instrument to fully, or nearly fully relax, will vary. If really excessive stresses are in the instrument, it may never be able rid itself of individual tensions, and reach its full potential. So my concept of "playing-in" has to do with the concept of individual parts of the instrument vibrating with their own tension, and the instrument resonating as a total thing once the tensions disperse, and let the instrument act a a unit. Not the total answer, but a large part of it. And, for whatever reason, seasoned instruments will "go to sleep", only to awaken when starting to be played for a short time. Witchcraft? Assuredly so, and only part of the myriad of factors adding or detracting in stringed instrument performance.

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Bear Acker
Amherst, Massachusetts






"If you knew what you needed to know, you'd know, ya know"

Making an observation of this thread I think most would agree that guitars change in tone from when they are first strung to a point in time after they have 'vibrated' for a while. I don't think anyone has said that playing in an instrument has chnaged the tone for the bad.

I subscribe to the theory that you can't judge any of my new guitars until they've been played for a while. As a result, when I put strings on the first time, I will mess around a little, try not to judge, and then hang it on the wall with a five dollar, Walmart aquarium pump attached to the strings. It will rattle and ring and vibrate for a couple days and the difference in tone is typically very noticeable.

So, although we can't predict exactly what will happen, we can at least play in a guitar and find out in a relatively short time.

Regardless, good luck.

Dave

im not ruling out psycho-acoustics, but i started a guitar back in november or so and got the box complete pretty quick, 6 weeks or so. its since been sitting in my room mostly untouched, except for the occasional stop to pick it up and tap it, look at it and go "oh man, that looks nice!" when i first completed the box, the tap seemed well, less than lively. 8 months or so later, it seems quite lively and i cant wait to get it strung up. anyone else experience anything like this before you even get the guitar strung up? all in my head?

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sweat the small stuff.