Wood density holds key to Stradivarius sweet sound

[sleepysurf]

Interesting study which explains why a Stradivarius sounds so good...

LONDON (Reuters)
Researchers using a medical scanner have worked out why a Stradivarius violin sounds so good -- it is because of the remarkably even density of the wood. For the past 300 years, musicians and scientists have puzzled over the unparalleled quality of classical Cremonese violins made by Italian masters like Antonio Stradivari and Giuseppe Guarneri del Gesu. Now a Dutch doctor and a violin maker from Arkansas think they have cracked the mystery after comparing five classical and eight modern violins in a computed tomography (CT) scanner normally used to examine patients. Using an adaptation of a computer program developed to calculate lung densities in people with emphysema, they were able to analyze the physical properties of violins without risking damage to instruments worth millions of dollars. They found no significant differences between the median densities of the modern and the antique violins but did discover far less variation between wood grains of early and late growth in the old ones. Since differentials in wood density affect vibration and therefore sound quality, the discovery may well explain the superiority of the Cremonese violins, they reported in the online journal PLoS ONE on Wednesday. So why is the maple and spruce wood in a Stradivarius so different? Part of the reason may be that trees grow slightly differently today than in the past. "Climate difference could explain part of it but treatment of the wood could be another explanation. A third answer could simply be the ageing of the wood over the past 300 years," Dr Berend Stoel of the Leiden University Medical Center told Reuters.
"There is no way of knowing from this data; we've just shown there are density differences." Still, Stoel and U.S. violin maker Terry Borman think the research may help modern instrument makers seeking to replicate the work of the Italian masters.

Their paper is available at http://www.plosone.org/doi/pone.0002554

 

[amey01]

Really interesting.

 

[JonFo]

Sleepy, great find, thanks for sharing.

This might explain why the higher the density of acoustic treatments, the better the sound of the speaker system in question.

Check out my new threads on this topic in a few days

 

[Gordon Gray]

Thank you Jonathan for the technical insight. You are quite the techno wizard.

By the by and IMHO, one of the reasons Pierre Sprey / Mapleshade uses maple in his amplifier / speaker platforms and equipment racks.

GG

 

[sleepysurf]

The confounding factor in all of this is the actual "resonance" of the room itself! The President of our local Tampa Bay Listening Society runs a business catering to musicians and (extreme) audiophiles, who want to alter the "tone" of their listening room/components/musical instrument via the use of small and large wooden resonators (amongst other things). In his opinion, every object in the room is part of the equation, and even miniscule changes can have a profound impact. I can't honestly say I hear every change with his resonator (or cable) tweaks, but his own listening room/studio is quite impressive sounding. This scientific study certainly adds credence to the critical role of the physical structure of things audio-related.

 

[risabet]

Interesting study which explains why a Stradivarius sounds so good...

Interesting, yes, explanatory, not necessarily. This study certainly points out one possible cause for the tone of the great master violins but since there are numerous other variables that weren't, and probably can't, be controlled, one would be hard pressed to say definitively that this is the reason.

 

[Tj Bassi]

Stradivari's violins have been poked, prodded and examined using all sorts of modern equipment and techniques yet no single factor can attest to the tone quailty of those older instruments. Dr. Joseph Nagyvary took a good shot at reproducing that tone and his findings can be found here:

http://www.nagyvaryviolins.com/mystique_and_intrigue_of_the_stradivarius.html

Having personally auditioned a Nagyvary instrument a few years back I thought it came fairly close to reproducing the characteristic sound of the old Italian violins, so his research must be somewhat valid.

Interesting nonetheless.....

Tj

 

[jk319]

Interesting indeed. I used to be a very avid violinist as well as guitarist. My own german Kloz (the eldest) is well over 200 years old. I wanted an english Craske, but the Kloz was a lot easier to play and half the price. Just w/o the He-Man tone, hehe. I've handled very fine Italian instruments, including a Strad. My good friend from music school performed on Jascha Heifitz's old del Gesu before. Her own instrument was worth $80k, and each of her bows cost 2 pairs of Summits. I already knew of that del Gesu violin that a long time ago scientists replicated the instrument to 1/1000 of an inch, with a chemically analyzed and reproduced varnish. (from watching a black and white documentary on Heifitz). Nope, didn't sound the same. OTOH, Im curious how much science has evolved to better the chances.

Density can very well be a major factor that is missing? I have both spruce and cedar guitars, and the former is very close grained German spruce. I believe spruce is about 4x the density of cedar. They definitely have their distinct sounds, but OTOH its really the luthier's construction that over-rides everything in the sonic signature.

The strad I played with in LA has a VERY different shape. This was about 16 years ago I believe. Its simply smaller, but perhaps a bit fatter in the middle. This will obviously be a big factor compared to "today's modern instruments".

Amati used to go out into the forests with a mallet/hammer and literally hit the tree with his ear to it. He would go around till he found a tree that he liked.

There are a lot of fine instruments out there, and honestly, $5-$20k can get you a very,very, very fine instrument if you know what you're doing.

 

[jk319]

I should add that the density will affect the time to break in an instrument. Of course the time is very dependent on the performer, but for example a cedar guitar can take only a month or two, while the spruce could be on the scale of years for some. Violins/cellos, etc are usually about a year to two. So, when they compare, I wonder if they should break them in a little. I don't necessarily believe in breakin with AV, but its an absolute with musical instruments.

 

[JonFo]

The confounding factor in all of this is the actual "resonance" of the room itself! ...

Yep, one needs to control the micro-dynamics of the items in the room as well.

That's why some of the best solutions for a dedicated room wind up being rather sparse in terms of decor, as anything you hang on the wall or put on a shelf will be energized by loud volumes and resonate, vibrate or otherwise make its own noise.

The very room structure itself might resonate at certain frequencies (not just the room modes caused by its dimensions). Which is why construction of listening rooms/HT's is critical.

As a for instance: My HT's walls are 2x6 framing, with double reinforced OSB/ cross braces on the outside, double layers of insulation over the external OSB, then hardiplank siding (which is fiber-cement and rock solid).
On the interior, the drywall is glued to the framing, then screwed every 4 inches in each direction (yes, screws, as nails will pop out in a room vigorously exercised by a monster IB sub).

The interior of the walls is overstuffed with insulation all around ( all six sides) to reduce internal resonances.

The room has never made any noise, regardless of how hard I push the IB.

The one downside of an overly rigid, resonance free structure is it does not absorb much energy itself (which helps explain the +4dB at 18hz in-room response of the sub), so in-room treatments are required. Not a problem now for me

As part of some recent acoustic enhancement work, we did have to pay close attention to resonances of the new artifacts to ensure they were vibration-free. Plenty of rubber, silicone, wire wrapping etc. went on to ensure the lack of buzzes or rattles.