sides glued together. This typically yields a very heavy and stiff sidewith a thickness of 4 mm and is usually, but not always, coupled by anextremely massive back. (These double sides were, to the best of my knowledge,first introduced by Daniel Friedrich, but he never used thick backs.) Back andsides this thick will not vibrate much, and therefore very little energy fromthe string will be wasted in these parts. The maximization of thestiffness-to-mass-ratio is achieved by constructing a lighter but stiffersoundboard. One possibility, for example, is gluing a sandwich of two very thincedar soundboards back and front onto a very light and stiff synthetichoneycomb-structure made from aramid fibers, or by laminating carbon fibre withbalsa wood (the lightest wood there is) and/or by using struts laminated in thesame way, or by any combination of similar methods. The result is a louderguitar. So whats wrong with this new approach to guitar construction? Nothingis wrong. I just heard one of these guitars in concert the other day. It wasreally loud, and I got headache and bellyache, and just hoped the concert wouldbe over soon. I really suffered physically from the sound of the guitar, butsaid to myself that this is an example of deformation professionnell. But to mysurprise, I found I wasnt alone: after the concert I heard several people, whoI knew were not guitarists, relate the same symptoms. Later, three guitarists,who had been among the audience, too, confessed that they had not liked theconcert at all, but would have never dared to say so openly, because the artistis a highly respected player in the guitar community. There were many moreguitarists present at this concert. What will be their honest opinion? But Idont want to start a discussion about the genesis of mainstream here, butrather get on with a more scientific criticism. Along with an increase ofefficiency comes almost unavoidably an increase of admittance of thesoundboard. That means energy from the string is transferred faster to thesoundboard. The admittance depends on frequency and even if the resonancefrequencies of the soundboard are well placed, the balance of the guitar willsuffer dramatically just from this 2 effect. Wolf notes and holes1 becomemuch more audible, but even more severe is a tendency to general overcoupling.Overcoupling means that the string is not telling the soundboard what to do,but rather the other way round, as it were. This causes a distortion of notesor of partials of notes. Such notes sound somewhat queer to the listener, butit takes a very trained ear to distinguish the precise nature of thedistortion. Often, it is only one inharmonious partial note, but with asurprisingly high sound level. In extreme cases, overcoupling is enough torender a guitar impossible to tune, especially when it is one of other sourcesof faulty intonation.2 A high average admittance is what the player calls afast attack of the guitar. Explosive or percussive sound are other commonequivalents, and I want to emphasize that these elements of sound are vital forthe guitar to be a guitar. Percussive means containing a lot of noise, i.e.non-harmonic or chaotic oscillation. High admittance also means that due