Holzkombinationen

Alles, was mit akustischer Gitarrenmusik zu tun hat und sonst nirgends hineinpaßt

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Gast

Beitrag von Gast »

Öhm, sorry :oops:
war ernst gemeint.
Aber nun weiß ichs ja.

Viele Grüße
Tom
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Beitrag von Admin »

@Erniecaster: Ich hatte Dich anfangs mißverstanden, nach nochmaligem Lesen war es aber klar: Du sprichst vom Klang, ich sprach von den physischen Eigneschaften des Materials. Allet klar.
chevere

Beitrag von chevere »

Hier noch was Interessantes von Meister Stenzel:

http://stenzel-guitars.de/deutsch/artik ... lzer_d.pdf

Greetz
Gast

Beitrag von Gast »

Hallo chevere,

dieser Artikel ist wirklich sehr gut.
Den Unterschied zwischen Zeder und Fichte hat er wirklich gut rausgearbeitet.
Schade, dass der Artikel auf Seite 2 schon vorbei ist. Das Ende ist etwas abrupt. Ich hätte gern noch mehr gelesen.

Viele Grüße
Tom
chevere

Beitrag von chevere »

chevere

Beitrag von chevere »

Hier der Artikel aus der "American Lutherie":


Dana Bourgeois has been designing and building acoustic guitars for over a quarter of a century. He has often lectured on the subject, and has also written several influential articles on various aspects of the guitar building art, most notably about tonewoods, and about the voicing and bracing of acoustic guitars. Reprinted below is his article from the March/April 1994 issue of Acoustic Guitar magazine. If you would like to learn more, check out the "Dana in Print" section on the Bourgeois Guitar website. There you will find the transcription of Dana's lecture at the 1990 Guild of American Luthiers convention, which the editor of American Lutherie magazine deemed "perhaps the strongest article ever published in American Lutherie about voicing the top and bracing of the steel string guitar," and you will also find Dana's most recent offering on the subject, "Still Voicing, Still Dreaming" from the Spring 2000 issue of American Lutherie.



Tapping Tonewoods, by Dana Bourgeois

How the Selection of Species Helps Define the Sound of Your Guitar

Acoustic Guitar Magazine, March/April 1994

Why is it that different woods are used for acoustic guitars, and how do these woods affect the sound of the instrument? In the past, there was less opportunity for confusion on this issue, since most guitars were made of mahogany, rosewood, maple, ebony, and spruce. But with the dwindling availability of traditional tonewoods, particularly those cut from old-growth forests, major manufacturers and smaller luthiers have been compelled to consider the use of alternative species of tonewoods- some of them common and others decidedly uncommon. This article looks at the strengths and weaknesses of the woods most commonly used today for tops, backs and sides, fretboards, and bridges.

Evaluating Tonewoods

Differences between woods can be as mysterious and complex as differences between people. Even within a species, no two pieces of wood are exactly alike. Environmental conditions, genetics, the age of the tree, annular growth patterns, grain orientation, curing conditions, and so on all have an effect on the tonal properties of a piece of wood. In addition, tonewoods respond differently in the hands of different makers. They can also take on different characteristics when used in different models of guitars-even those built by the same maker. And whether a particular wood sounds good or bad depends partially upon who’s doing the listening. So any attempt to sort out distinctions between tonewoods can only be offered from a relatively subjective point of view.

When evaluating tonewoods, luthiers must take into account a wide variety of factors, some of which can be inscrutably subtle, and most of which are likely to vary in priority from one luthier to another. I tend to place a good deal of importance on a couple of elements that, when viewed together, illuminate much of my own understanding of tonewoods.

Velocity of sound refers to the speed at which a material transmits received energy. Simply described, plucked guitar strings transmit energy to the bridge. The bridge in return oscillates one surface of a ported enclosure, setting up sound pressure waves that eventually reach the eardrum. In order to contain this chain reaction, one must design an efficient ported enclosure and then make it out of materials that facilitate the transmission of the vibrational energy. Lively materials-those with a high velocity of sound, or low internal dampening-make the best facilitators.

There are a number of ways in which luthiers judge the sound velocity of wood. The most common method is to hold the wood at a nodal point, tap it, and then listen for the response. (Nodal points are analogous to the locations on a guitar string where natural harmonics can be played.) The difference between a high and a low velocity of sound can often be so apparent that one demonstration is usually sufficient to teach an apprentice how to select most of the good sets out of a given stack of wood. Sometimes a piece of wood is so lively that it doesn’t seem to matter where you tap it or where you hold it. I remember going through a large stack of aged Brazilian rosewood from which I was able to make my selection the moment I lifted a piece off the top of the pile; rubbing one piece of wood against another was enough to make the best sets ring!

In addition to testing for velocity of sound, luthiers also make use of the tapping technique to listen for harmonic content. Like a string, a piece of wood is capable of producing a fundamental tone and an array of harmonics. Though the presence and strengths of individual harmonics are distinctly influenced by changes in the geometry and mass of the piece of wood, elements such as clarity of tone, relative harmonic complexity, and high, low, or mid bias can readily be discovered by holding and tapping a piece of wood in a variety of ways.

Topwoods

Each part of the guitar seems to play a role, be it significant or subtle, in determining the tonal characteristics of the instrument. In very general terms, the top, or soundboard, seems to affect the guitar’s responsiveness, the quickness of its attack, its sustain, some of its overtone coloration, and the strength and quality of each note’s fundamental tone. Most luthiers (but not all) believe that the wood chosen for the top is the single overriding variable that determines the quality of tone of a finished instrument.

Spruce is the standard material for soundboards. These days the most commonly used species is Sitka, due to its availability and to the high yield from its characteristically large-diameter logs. Quartersawn Sitka is quite stiff along and across the grain; high stiffness, combined with the relatively light weight characteristics of most softwoods, is a recipe for high velocity of sound. A strong fundamental-to-overtone ratio gives Sitka a powerful, direct tone that is capable of retaining its clarity when played forcefully. Sitka is an excellent choice of topwood, then, for players whose style demands a wide dynamic response and a robust, meaty tone. On the other side of the balance sheet, the lack of a strong overtone component can result in a "thin" tone when played with a relatively light touch-depending, of course, upon the design of the guitar and the other woods used in its construction. The break-in period for a new Sitka guitar can also be longer than that of other spruces.

The most common alternative to Sitka is Engelmann spruce, another domestic western species. Engelmann is often more expensive than Sitka due to the lower yield from its smaller logs and because most logs have a spiral-grained structure that renders them unsuitable for proper quarter-sawing. Engelmann is considerably lighter in color than Sitka spruce, lighter in weight, and usually less stiff, resulting in a slightly lower velocity of sound. Engelmann also tends to exhibit a weaker fundamental tone, although it produces a noticeably broader and stronger overtone component. It is therefore a good choice for players who require a richer, more complex tone than can be obtained from most Sitka tops, particularly when the instrument is played softly. The downside is that Engelmann tops can have lower "headroom" than Sitka tops, which is to say that clarity and definition are often sacrificed when the guitar is played loudly.

European or silver spruce, the spruce of choice for makers of classical guitars, shares a number of characteristics with Engelmann spruce, including color, lightness of weight, harmonic complexity, and fullness at the lower end of the dynamic range. Because of its visual similarity and significantly higher cost, its name has been affixed more than once to a piece of Engelmann spruce by unscrupulous (or uninformed) wood dealers and luthiers. European spruce differs from Engelmann in its potentially quicker response and greater headroom. The availability of anything better than mediocre European spruce (which is easily exceeded in quality by the better grades of Engelmann-a commodity that is still readily obtainable) is sharply limited, unless the boards are selected at the source in Europe.

Eastern red spruce, also known as Adirondack or Appalachian spruce, was the primary topwood used by American manufacturers before World War II. Its use was all but discontinued due to over-harvesting of the resource but has recently been reintroduced thanks to 50 years of regeneration and to the legendary status that this traditional tonewood has attained. The small size of most logs and a shortage of wood conforming to market preference for even color and regularity of grain conspire to keep the price of red spruce extremely high.

Red spruce is relatively heavy, has a high velocity of sound, and has the highest stiffness across and along the grain of all the topwoods. Like Sitka, it has strong fundamentals, but it also exhibits a more complex overtone content. Tops made out of red spruce have the highest volume ceiling of any species, yet they also have a rich fullness of tone that retains clarity at all dynamic levels. In short, red spruce may very well be the Holy Grail of topwoods for the steel-string guitar. If players and builders were able to overcome phobias about unevenness of color, grain irregularity, minor knots, and four-piece tops, many more great-sounding guitars could be produced while the supply of potentially usable red spruce is still available. Old-growth woods are disappearing so fast that such an attitude change will need to be scheduled sometime in the near future, unless the majority of new guitars are to be made of synthetic materials.

Before leaving the spruces, I should mention bearclaw figure, or hazelficte-a delightful pattern in the grain occasionally occurring in all species of spruce. Bearclaw, like the curl in curly maple, is a rippling of the longitudinal fibers, which divides the surface of the wood into shimmering patterns. Unlike the even waves that usually occur in maple, bearclaw usually appears on asymmetrical or randomly broken patterns. This phenomenon almost always occurs in older trees that have dense, stiff grain structure and high sound velocity. Thus bearclaw is usually a reliable indicator of the better examples of tonewoods within any given species of spruce.

Western red cedar ranges in color from honey brown to light chocolate. It has a quickness of sound that exceeds any of the spruces, a higher overtone content, lower fundamental content, and lower stiffness along the grain. Additionally, cedar tops require a significantly shorter break-in period than spruce tops, a phenomenon that a few dealers of new guitars are beginning to pick up on.

Since World War II, cedar has been used extensively by makers of classical guitars. Cedar-topped guitars are characteristically lush, dark-toned, and bursting with flavor. They are often less powerful in projection than their spruce cousins, however, and they tend to lose clarity near the top of their dynamic range. Having enough bottom end is never a problem for a cedar guitar, although preventing the sound from getting muddy sometimes is. Because of its pronounced weakness along the grain, I find cedar to be used to its best advantage in smaller-bodied guitars or with non-scalloped braces. Redwood is usually darker in color than cedar and often displays the same general tonal characteristics, leaning slightly toward darker tones, less definition in the bass, and lower velocity of sound.

Koa and mahogany have been used for soundboards since the ‘20s, and makers have recently begun to use maple. These hardwoods have in common a relatively low velocity of sound (as compared to softwood tops), considerable density, and a low overtone content. They therefore tend to produce a solid tone-though not an especially rich one-and respond best at the upper end of the dynamic range. Mahogany-topped guitars exhibit a strong "punchy" tone that is well-suited to country blues playing. Koa has a somewhat more midrangy tone that works well for rhythm and truly shines in guitars made for Hawaiian-style slide playing. Maple, in particular, having the lowest velocity of sound of the three, can be downright flat-sounding-a blessing in disguise when a guitar is amplified at high sound-pressure levels.

Back and Sides

Besides serving to form the enclosure of the soundbox, the back and sides of the guitar also act as a sympathetic resonator whose oscillations contribute greatly to the harmonic mix. When judiciously selected (with due consideration given to design criteria and the other tonewoods used in the instrument), the back and sides can have a tremendous effect on the overall tone of the instrument.

Brazilian and Indian rosewood have an extremely high velocity of sound and a broad range of overtones. The rosewoods, as well as their various rain forest cousins-cocobolo, kingwood, morado, and the like-have strongly pronounced low overtones, usually the lowest resonating frequencies in the entire guitar. These lows help to create a complex bottom end and to impart an overall darkness of tone to the instrument. Strong mids and highs serve to reinforce overtones generated by the top, contributing to a fatness of tone on the upper registers. Guitars made of rosewood also have a pronounced "reverby" tone, caused by a strong, clear set of sympathetic harmonics with a delayed onset and slow decay.

I’ve found that Brazilian rosewood has everything that Indian rosewood has, only more. I say this with great trepidation in light of that species’ likelihood of extinction within a couple of generations. An international embargo on trade on Brazilian rosewood products guarantees that the relatively few sets remaining in this country, which may be used only on domestically sold guitars, will continue to spiral in price as the supply dwindles.

Mahogany and koa have relatively high velocities of sound when considered as materials for backs and sides and thus contribute much to overtone coloration. Lacking the low-end frequencies of the rosewoods and also their sustaining reverberation, these woods have an altogether different sound. Where rosewood guitars can be thought of as having a "metallic" sound, mahogany and koa guitars are better described as sounding "woody, although the harder, more dense examples of these woods can take on some of the characteristics of the rosewoods. Between the two, koa seems to have a little more fullness in the midrange, while mahogany tends to favor the bass (to some extent) and the treble.

Maple and walnut tend to be more acoustically transparent than other tonewoods, due to a low velocity of sound and a high degree of internal damping. That is to say that they allow tonal characteristics of the top to be heard without the addition of extraneous coloration and may even serve to attenuate some of the overtones emanating from the top.

The harder, denser examples of these woods, such as sugar maple and black walnut- particularly quartersawn examples-tend to lean slightly more toward the tonal direction of mahogany, while softer examples, such as bigleaf maple and claro walnut, tend toward greater tonal transparency. Curly, quilted, or bird’s-eye figures do not seem to have much effect on the tone of the wood, but they can be used, like bearclaw, as an indicator of other properties. Quilted figure, for example, occurs most often in softer species and is best displayed when the wood is flat sawn-two characteristics that tend to produce higher damping properties.

Fretboards and Bridges

Players of electric guitars with bolt-on necks have long been hip to the fact that neck and fretboard materials can have a significant bearing on tone. Maple necks can impart a bright, poppy tone that can do much to reinforce the top end of a large-bodied guitar, while mahogany necks help push the overall palette into a warmer, more woody tonal range.

Fretboard materials also exert an influence on overall tone, although they probably act more as icing on the cake than as a layer of the cake itself. Brazilian rosewood fretboards and their denser rainforrest counterparts add sparkle and ring, and Indian rosewood fretboards can help fatten up the midrange. Wenge, a dense, dark-colored African hardwood unrelated to the rosewoods, has tonal properties remarkably similar to those of Brazilian rosewood.

Ebony, the traditional fingerboard material found on violins, classical guitars, and high-end steel strings, has the lowest velocity of sound of all the woods commonly used in lutherie and has definite damping characteristics. This may not prove to be much of a problem for large-bodied guitars made out of red spruce or Brazilian rosewood, but it may be something to consider when designing smaller guitars, particularly those using some of the less resonant woods for tops and backs.

Bridge materials, like fretboards, cannot make or break an instrument, but they serve to enhance or edit the tonal contributions of other materials found on the guitar. The woods discussed above-ebony, Brazilian rosewood, and Indian rosewood-contribute similar tonal qualities when they are used as bridge materials as when they are used for fretboards.

It is important to remember that wood, when considered generically, can be responsible only for certain aspects of the tone of any guitar. Equally important are the design of the guitar, the skill of the maker, and the quality of the individual pieces of wood from which the guitar is made. Species selection can, however, be a determining factor in the creation of a very special guitar or a guitar designed for a specific purpose.


Our thanks to Acoustic Guitar Magazine for permission to reprint this article.
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RB
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Beitrag von RB »

Das ist nicht gan uninteressant. Allerdings hatte ich anfangs in Erwägung gezogen, eine Übersetzung einzustellen, aber das ist ja eine Masse Arbeit. Hier die ersten paar Absätze:
Abstimmen von Tonhölzern

Wie die Auswahl an Holzsorten sich auf den Klang der Gitarre auswikt

Warum werden für akustische Gitarren verschiedene Tonhölzer verwendet und wie beeinflusst das den Klang des Instruments ? Früher gab es weniger Gelegenheit, über diese Frage in Verwirrung zu geraten,
weil Gitarren meist aus Mahagoni, Palisander, Ahorn, Ebenholz und Fichte hergestellt wurden. Aber mit der nachlassenden Verfügbarkeit der traditionellen Tonhölzer, speziell denjenigen, die aus alten
Waldbeständen gewonnen werden, werden Herstellerbetriebe und Gitarrenbauer mehr und mehr gezwungen, sich mit der Frage nach der Verwendung alternativer Tonhölzer zu befassen, manche
gebräuchlich, die anderen eher ungewöhnlich. Dieser Artikel unterzieht die Stärken und Schwächen derjenigen Tonhölzer einer Betrachtung, die heutzutage für Boden, Zargen, Decken, Griffbretter und Stege Verwendung finden.

Unterschiede zwischen Hölzern können so myteriös und komplex sein, wie Unterschiede zwischen Menschen. Sogar innerhalb einer Spezies werden sich zwei Stücke Holz nie ganz gleichen. Umweltbedingungen, die Gene, das Alter des Baums, das jährliche Wachstum und seine spezifischen
Spuren im Holz, der Verlauf der Maserung haben alle Auswirkungen auf die tonalen Eigenschaften eines Stückes Holz. Hinzu tritt, daß Tonholz in den Händen unterschiedlicher Baumeister auch unterschiedlich
zu reagieren scheint. Auch können sie in unterschiedlichen Gitarrenmodellen unterschiedliche Eigenschaften annehmen, auch wenn diese Gitarren von ein- und demselben Erbauer stammen.
Schließlich hängt die Frage, ob ein spezielles Holz "gut" oder "schlecht" klingt, auch noch wenigstens teilweise vom Zuhörer selbst ab. Somit kann ein jeder Versuch, die Tonhölzer hinsichtlich ihrer Klangeigenschaften zu unterscheiden, nur von einem subjektiven Standpunkt aus unternommen werden.

Wenn Tonhölzer bewertet werden, muß der Gitarrenbauer eine große Vielzahl von Faktoren in Betracht ziehen, von denen einige äußerst subtil sind, wogegen aber die meisten anderen von einem Gitarrenbauer zum anderen abweichen. Ich richte mein Augenmerk zum guten Teil auf eine Reihe bestimmter Faktoren, die zusammegenommen mein Verständnis von Tonhölzern repräsentieren.
Allerdings bin ich an der Vokabel "ported enclosures" gescheitert und war zu faul, weiterzumachen.

Die Erfahrung, daß die Bauform eine ganz entscheidende Rolle spielt, habe ich erneut am Montag Abend gemacht, an dem mir vergönnt war, auf OldPickers "Pummelchen" zu spielen, die bürgerlich Stanford RD-5V heißt und hinsichtlich der Bauform einer Martin 12-fret Dradnought entspricht. Die Holzkombination (Fichte/Palisander) würde sie ungefähr in dem Bereich HD-28VS von Martin einreihen. Nun habe ich sie mit der Martin CEO 5 verglichen (Sitka-Fichte/Sapele). Die Bauformen beider Giatrren, also die Abmessungen von Korpus und Hals sind beinahe gleich, mit zwei Unterschieden: Der Zargentiefe der Martin scheint etwas dicker, wogegen diejenige der Stanford sich in Richtung Halsansatz leicht verjüngt. Außerdem hat die Martin eine um ca. 5 mm kürzere Mensur, was man allerdings beim Spielen kaum merkt. Die Deckenhölzer, in beiden Fällen Fichte, könnten unterschiedlicher nicht sein. Stanford: Gleichmäßig gemaserte, sehr feinjährige Fichte. Sie sieht nicht nach Sitka-Fichte aus, das ist für mich aber als Holz-Nichtfachmann nicht sicher einzuschätzen. Martin: Eher weite Maserung, die zur Mittelnaht der Decke immer feiner wird, zudem Wuchsfehler, die man als "Bearclaw" bezeichnet, wobei die Auswahl der Decke nicht nach allerstrengsten Gütkriterin erfolgt zu sein scheint, denn die Wuchsfehler wirken eher grob und sind wie von der Hand eines Tölpels über die Decke verstreut.

Und dann der Klang beider Gitarren, desgleichen das Ansprechverhalten und die Lautstärke: Fast identisch. Die Unterschiede sind so geringfügig, daß man sehr genau hinhören muß. Bestenfalls könnte man sagen, daß die Stanford minimal, aber wirklich nur minimal höher abgestimmt ist, als die Martin. Beide haben klare, singende Höhen mit schönem Obertongeflecht drüber, beide einen enormen Druck in den unteren Mitten und tirische Lautstärke wenn man etwas kräftiger zulangt. Beide eignen sich als Strummer und als Fingerpicker, desgleichen für Flatpick-Solos. Es ist tatsächlich schwer, die beiden klanglich und spieltechnisch auseinanderzuhalten.

Eines muß ich sagen: Ich mag diese Bauform. Sie ist für mich fast die eierlegende Wollmilchsau. Und Frantisek Furch hat nicht zuviel versprochen, als er in einer Werbeanzeige sagte "Der Klang entspricht den Originalen".
chevere

Beitrag von chevere »

Hallo Rb,

ported enclosure:

vielleicht "...datt Teil wo der Steg drinne is"

Bestandteil der bridge sozusagen. Fachtermini incl. (Deutsch-English) werden mit Sicherheit baldigst von kundiger Seite erläutert.

Wie wär`s,
Mr. Teja Gerken,

hast Du nicht eine zutreffende Übersetzung parat?

Grüße
chevere

Beitrag von chevere »

Nach soviel Text mal wieder...

http://www.sheppardguitars.com/new_page_7.htm

Viel Spass
chevere

Beitrag von chevere »

...Interessantes zum Thema von Mayes (Gitarrenbauer):

http://www.mayesguitars.com/frames.html bitte "tonewoods" anklicken.

Greetz
chevere

Beitrag von chevere »

Gast

Beitrag von Gast »

Hallo chevere,

mensch dat find ick ja echt dufte von dir, wa.

So langsam kann man sich ja als Experte in Sachen Tonholz bezeichnen, wenn man alle Beiträge aufmerksam gelesen hat.

Schön.

Viele Grüße
Tom
chevere

Beitrag von chevere »

freut mich, dass es Dir gefällt und ich hoffe die anderen sind nicht davon genervt.

Aber ich denke mir, dass man für den Fall des Interesses an diesem Thema, dann schon mal ein wenig Einstiegsmaterial (mal zum Nachschlagen) hat und nicht erst noch die zeitraubende Internetrecherche oder/ und möglicherweise nicht so gut strukturierte Datenvielfalt des heimischen Rechners durchsuchen muß.

Viel Spaß!
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