Students engineer better music


MIT student musicians have applied their expertise in engineering to their instruments, resulting in inventions that could improve the performance of electric guitars and drum sets.

Bryan Smith's pickup system for electric guitars could, among other things, soften the hiss when that instrument is played loudly, while a bridge for the same instrument designed by Mr. Smith and Daniel Walczyk will allow for easier adjustment of the strings and could enhance the acoustical quality of a plucked string.

Mr. Walczyk also developed a system that allows a musician to change the sound of the snare drum during a performance. And Susan Ward created an adjustable foot pedal for different ways of playing the HiHat cymbals that are part of a drum set.

The four inventions are in different stages of development. Prototypes of the guitar inventions are underway; those for the snare drum and cymbals are completed. All are also in different stages of the patent process-a patent application for the pickup system is being prepared, there are plans to do the same for the bridge, a patent has been filed for the snare drum, and one was awarded for the HiHat foot pedal last fall.

PICKUP SYSTEM

All electric guitars have two or three rectangular pickups located on the body of the instrument below the strings. "The sound from the instrument comes directly from the pickups," said Mr. Smith, a senior in physics and electrical engineering and computer science who is also working on his SM degree. "Pickups convert the vibrating string into an electrical signal that is amplified and pumped to your speakers."

Mr. Smith's system, which will be located inside the body of the instrument, consists of electronics that affect different qualities of the pickups. For example, the new system will increase the signal-to-noise ratio of the pickups, which reduces the hiss when the guitar is played loudly.

Dubbed CHI, for Controlled Harmonic Interaction, the system will also restore certain frequencies, or sounds, to the instrument. "In an electric guitar the vibrating string has some frequencies that are lost on the way to the speaker," explained Mr. Smith. "CHI restores these, which gives the frequency equalizer-the device that adjusts the bass and treble-more to work with. It adds another tone color to a musician's acoustical palette."

Mr. Smith is currently developing a prototype of the device with Mike Tobias, who is well known in the music industry for his custom-designed guitars. (Mr. Smith used to play bass guitar for the NBA's LA Lakers' band, and met Mr. Tobias when he asked the latter to build him a custom instrument.)

NEW BRIDGE

While developing CHI, Mr. Smith recognized that the traditional bridge of an electric guitar, or the device that raises the strings over the body of the instrument, could also be redesigned. To that end he approached Mr. Walczyk, a graduate student in mechanical engineering whom he'd met when both were members of the MIT Festival Jazz Ensemble. Together they came up with a design that allows the user to easily adjust both the height of the strings over the guitar, the distance between the strings themselves, and the length of the strings.

The new bridge could also allow each plucked string to vibrate longer while retaining a clear articulation of each new note. Messrs. Walczyk and Smith accomplished this by using advanced materials in the design. "We fashioned the bridge into a sort of `acoustical lens,' " Mr. Walczyk explained. This "focuses the sound that's been transferred to the body of the guitar back into the string."

The inventors say that the new bridge will be easy to manufacture, and note that it does not require the guitar to be reworked or modified in any way. "Some new bridge designs require that the instrument be routed out to make room," Mr. Smith said. "Ours is a simple swap with the old bridge."

The same applies to CHI. "The technology is intended as an augmentation, not a replacement, of current instrument designs," Mr. Smith said. "A lot of research went into the design of the electric guitar, and the last thing I want to do is discard all of that effort."

SNARE DRUM

Mr. Walczyk has also developed a device that allows a musician to adjust the sound of the snare drum, the instrument used in a drum roll. A drummer himself, it occurred to Mr. Walczyk that it would be ideal to be able to quickly change the sound of the drum during a performance without resorting to electronic effects.

So as an undergraduate at Rensselaer Polytechnic Institute, he developed a way to adjust different parameters-such as the snare tension and muffle placement-by simply moving a lever. Mr. Walczyk has continued working on the device at MIT.

CYMBAL SYSTEM

When Ms. Ward was a member of the Festival Jazz Ensemble, the group's drummer asked if she could design a more flexible cymbal system for him. An undergraduate in mechanical engineering at the time (she has since graduated), Ms. Ward came up with a device that allows for different ways of operating the HiHat cymbals. She developed the device for her bachelor's degree thesis.

The HiHat cymbals in a drum set are operated via a foot pedal that claps the cymbals together. In Ms. Ward's device, this pedal can be operated either traditionally (with the toe), or with the heel. "I found that most people are very good at tapping with the heel, and can do it for longer and get less tired."

She also noted that "drummers get used to different settings for their HiHats, so I made this device adjustable for all of those settings." Her patented invention is also mobile, so the HiHat can be positioned wherever the drummer wants it.

Mr. Smith and Mr. Walczyk developed their inventions in addition to their thesis work (Mr. Smith is studying nanoelectronics; Mr. Walczyk is studying rapid tooling for sheet metal forming). Said Mr. Walczyk, "it's a natural progression. We're musicians, we see a lack of something in the current technology, and we have the training to use existing technology to address these concerns.

"Plus," he added, " it's a heck of a lot of fun."

A version of this article appeared in MIT Tech Talk on June 7, 1995.


Topics: Humanities, Innovation and Entrepreneurship (I&E), Students

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