CelloStone

Who We Are



We all see the world through the lens of our training;
and sometimes we are lucky enough to find a new insight.

The CelloStone came from the collaboration of a luthier and a geophysicist. An unlikely pairing of an artist and an engineer. Both brought to the table a unique set of skills and interests, which resulted in a unique patented product (US Patent # 8,735,702) not easily explained by the current state of the art for the physics of the cello.

She received a Bachelor of Science (BS) in Math and Geology from Portland State University and a Masters of Engineering (ME) in Geophysics from Colorado School of Mines. She is a Registered Professional Engineer (PE) in Colorado and a Registered Geologist (PG) in Wyoming. For over 30 years she interpreted seismic data (mostly compressional waves - acoustic waves if they are in air) as it pertains to exploring for hydrocarbons. She has authored and presented 14 papers on different aspects of interpretation and understanding compressional waves to the Society of Exploration Geophysicists (SEG) International meetings, European Association of Exploration Geophysicists (EAEG) meetings, Australian Association of Exploration Geophysicists (ASEG) meetings, SEG Summer Research Workshop and to SEG chapter meetings. Many of these papers were invited and some were awarded best paper. In addition, she taught a three-day course on seismic interpretation requested by the SEG.  She has also worked as a Geotechnical Engineer in the housing industry.

She is married with one daughter. Deborah, her husband and daughter are volunteers with the Loveland Ski Patrol. She is the CPR Advisor and a Mountain Travel and Rescue Instructor for the ski patrol. She also teaches Cardio Pulmonary Resuscitation (CPR) for the Red Cross. She is an avid hiker in the summer, skier in the winter.

In June 2008, the family bought our daughter a German made student cello. The luthier made the comment that the old plywood cello could not sound as good as a solid wood one. The luthier explained that the plys of the plywood interfered with the movement of sound in the cello. The geophysicist wondered why the plys interfered. This started her reading on acoustics. The more the geophysicist read the more she found that the ideas of how a cello made sound were inconsistent with the plys causing a different sound. In other words, the “conventional wisdom” did not explain the plywood cello. The geophysicist kept reading hoping to find an explanation that fit the plywood cello. During this time, she become familiar with a significant portion of what had been written on the subject of acoustics of the violin family, the physics of the violin family and some of the acoustics of concert halls. She read about modal analysis, tonal copies, the Hutchins Octet, Helmholtz motion of the string and how it has been modified including C. V. Raman’s papers, the wave equation models and how they were derived, the electric circuit models, Oliver Rogers’ Finite Element models and the models of the bridge movement with its coupling to the body of the instrument. She read about the search for the specifications for the best tonal woods from which to make violin family instruments and even the history of how the Cremona instruments were saved. She found that the Boulder Public Library system had access to the Music School libraries at Universities in the most of the States around Colorado. That the University of Colorado Music School library had all the back issues of the Cat Gut Society and Violin Society of America Magazines and that the collection of the CV Raman papers were in the CU archives and available to Boulder Public Library Patrons. The more the geophysicist read the more she realized that a geophysicist looked at the physics of the cello from a very different perspective. She could not get the cello to fit what the physicists thought it did. If the cello fit the current state of the art of the cello; the CelloStone would not work. In essence the CelloStone is the first demonstration of the geophysicist view of the cello.

The luthier who originally made the statement about the plywood cello had a problem. His cellos had little or no wolf in his workshop and significant wolves in the cellist’s home or studio. The cello could come back to the workshop and be fine again and then go out to the cellist and the wolves were back. The geophysicist and the luthier discussed the luthier’s idea that it was environment, but the wolves returned even in places where the humidity was the same as the workshop. So what was different? Only the floor and floor covering were different. They figured out that the concrete floor was the difference. Sure enough if the cellist played in the garage or on a concrete basement floor, no matter what the humidity or temperature, the cello performed like in the workshop.

The problem is defined – Find a way to put a 4 foot by 8 foot sheet of concrete under a cellist’s arm so he can take it anywhere.

The problem mulled in the luthier’s and geophysicist’s heads for nearly a year. The geophysicist looking at dissipating the energy to the floor and the luthier wondering what about concrete was important. The geophysicist talked to other engineering friends and calculated that there needed to be 10” of material in order to get the desired effect. The luthier, experimented with some concrete blocks finding that a 20 pound block worked. Problem for the luthier was that the block only worked if the endpin was dead center. The geophysicist then asked the length across the block in the shortest direction it was 9 3/4” across. 10” was the right length. This sent the geophysicist on a shopping trip to all the stone tile stores in the area. Finally she found the travertine tile she was looking for at a small flooring store and bought some that tonally matched each other. Next she took them to cellist friends and got them to play on the tiles determining that it would take two tiles and that a 10” square on a 12” square tile would work. The geophysicist, hoping to find a ¾” thick rather than two tile solution, found a counter top of travertine and had 10” and 12” disks made. But they did not work as well as the tiles. The CelloStone was born.

The initial CelloStone testers, all of which were cellists making their living playing cello, were impressed that the cello’s wolf did not return even with changing temperatures and humidity. Taking the cello on tour, no longer was as much of a challenge with the wolf staying away as long as the endpin was on the CelloStone. Having the cello heat up under the lights on stage was no longer brought back or moved the wolf. The cello stayed the same (only the cellist was wilting). Other early testers found that the CelloStone made the bowing smoother and so long practice sessions no longer made their bow arm so tired it ached.

As the luthier and the geophysicist worked with the CelloStones they found that different cellos matched different tiles, that the tiles did not all match each other. In fact, finding two that matched required checking several different tiles. The geophysicist also showed the luthier that the travertine tiles picked worked but limestone, other travertines, granite, clay, marble, shales and clay tiles did not work. So it was like wood - you couldn’t just go to a lumber store and buy cello wood and you couldn’t just go to a flooring store and buy travertine. It was obvious they needed to buy all the travertine tiles in this shipment from the flooring store. As the luthier put it “they bought the whole tree after finding it was a good one”.

The geophysicist will find more travertine as this “tree” runs out. The geophysicist also showed the luthier that even though this set of travertine is from one quarry and one part of the quarry, about half of the tiles are not suitable for CelloStones. They will be sold for walls or tub enclosures.

Seismic exploration is creating seismic energy at the surface of the earth, using a thump or explosion and “listening” to the waves return. In layman’s terms this is similar to ultrasound but at very low frequencies. The seismic waves reflect off the layers of the earth and return to the surface where geophones (accelerometers) record the information. From the waves recorded a picture of the layers in the earth are recorded. In other words, I gathered rock property information from compressional waves and shear waves traveling through the Earth.

It appears your Web browser is not configured to display PDF files. Click here to download the PDF file.

A geophysicist works with seismic signals that travel through the earth with frequencies of the signals between 8 and 300 hertz. All of the information, interpreted by the geophysicist is in what a physicist would call very low frequencies. Physicists do not work with the lowest frequencies since they are very long wavelengths and so require long periods of time to measure (0.5 to 2 seconds). The physicists work with micro (10-6) and nano (10-9) second times. Physicists consider 1,000 hertz as very low frequencies. Usually the lab measurements of the properties of materials are done with signals in the 106 hertz range. Geophysicists have found that the measurements using the high frequency (106 hz) are not indicative of the response of earth materials to signals around 100 hz. The open strings of the cello vibrate at 65 hz (C) to 220 (A) hz.