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Welcome

My name is Chris Banta.

For the past fifty years (1973-2023) I've been exploring the design, fabrication, and tuning of various types of melodic bar percussion instruments.

1979 - Chris Banta with early instrument constructions

1976

2019 - Chris Banta in the shop with some of his percussion projects

2022

New Book Writing Project

 

​This website is going down a different direction.  I am currently transferring all this experience and data into a book writing project.  The attempt is to document all my bar percussion projects, processes, materials, and musical technicalities used in this lifelong endeavor. 


This book is an exhaustive photo and technical opportunity to explain and present the wonderful, tricky at times, and the never-ending romance of a really cool percussion instrument and subject.

 

(Heavily into the Research and Writing phase right now.)

Aiming to have it available on Amazon.com

New Book by Chris Banta:  The Romance of Instrument Design (Currently in Research and Design

Current Research Projects:

​​[Project No. 1]

"BARS" Design and Contruction of a 1-1/2 octave IPE bass marimba.

Research Objective:

Q: Are bars that are made from IPE [ee-pay] suitable for marimba and xylophone bars?  

IPE is an extremely dense and durable wood, and is used extensively on outdoor decks, ship decks, and in areas requiring an environmentally robust organic material.  Their mechanical robustness is not in question because they have a rated hardness of????.  Hardness ratings of marimba woods:

 

Oak =

Honduras Rosewood +

African Padauk = xxx

 

To test the suitability for bar percussion question, I am currently designing a 1-1/2 octave chromatic bass marimba (From: C2 to F3).  The one unknown feature at this time is when tuned, how the ring time and brilliance of pitch the bar's sound will be.

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Photo Below:  In marimba design and building, since everything starts with the bars and their pitch, rulers, straight-edges, T-squares, and bar spacer blocks are used to align the bars, so they are visually and symmetrically positioned for the performer.  This layout is also crucial for establishing the locations of the bar support rails and bar attachments points on those rails.

 

NOTE: All the rules for professional marimba bar design, construction, and tuning will be utilized, which includes:

(1) Straight length-wise grain with any curvature is less than 1/8" over the length of the bar

(2) Quarter-sawn [where the grain is (between 75 and 90-degrees perpendicular to the ground when lying flat on that ground, and

(3) harmonic tuning out to three harmonics

 

NOTE: Verifying mallet strike ring time and sustain qualities are currently in process using Honduras Rosewood and African Padauk as the professional instrument standards.

(Chris Banta) In-Process: 1-1/2 octave bass marimba bar set made from IPE.
Half-Wavelength Resonator - Designed and Built by: Chris Banta

Experiment No. 1

Goal: Half-Wave Length Resonator with switch-back routing designed to fit under the bars requiring no constraints within or beyond the outside boundaries of the frame

Plywood column - Open at both ends

Pitch: C2 (65.4Hz)

Column internal length: 8ft w/ adjustable slider for tuning

Findings Rating: (5)  Very powerful resonance coming from both ends (more so than a stopped Quarter Wavelength Resonator.

All harmonics sounding at once felt more harmonious and musical .

Concern: Is the improvement in overall resonance and sound worth the needed oversizing of the instrument?

Inside View: Half-Wavelength Resonator (Box Version) - Designed and Built by: Chris Banta
Half-Wavelength Resonator (Box Version) - Designed and Built by: Chris Banta

Experiment No. 2

Goal: Half-Wave Length "labyrinth" Resonator inside a closed box with openings at both ends - designed to fit several side-by-side within the constraints, boundaries and minimally protrude beyond the instrument's frame.

Findings Rating: (3) Not as powerful resonance as the column-type above.  Although resonance was created when striking the bar, sound felt "pinched and weaker" although was present when the bar was struck.  I suspect this was caused by the maze-like curves and back-&-forths possibly hindering the free-flow or movement of the wavefront.

 

Could also be a problem with viscous-drag along the inside walls due to slight roughness from the wood grain.  Will coat the inside with several clear-gloss coatings.  Then retest.

 Plywood sides and tunnel-like curves

Pitch: C2 (65.4Hz)

Column internal length: 8ft w/ adjustable slider for tuning (under development).

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[Project No. 2]

"Research and Development of a half-wavelength resonator approach which offers a more powerful acoustical resonance element than quarter-wavelength resonators.

 

Research Objective:

Q: Are half-wavelength resonators suitable for marimba and xylophone bars?  

In collaboration with the IPE bar set in No. 1, I am employing (1/2) half-wavelength column resonators, instead of (1/4) quarter-wavelength column resonators (used on standard marimbas), to amplify the resonant sound of the bar.

 

Here's the difference between the two resonator types:


(1/4) quarter-wavelength [column] resonators:

Requires a stopper at the opposite end of the opening which is place just beneath the underside center of the bar.  Because of the stopper, this resonator only exhibits the odd harmonics of the pitch (e.g. if the fundamental or bar's pitch is 100 Hz, then the odd harmonics would be: 100Hz, 300Hz, 500Hzz, 700Hz, etc. within the tube will be heard.

  • PROS: Shorter resonator columns

  • CONS: Only one opening for resonance to emerge (which is typical and normal for all marimbas).

 

(1/2) half-wavelength [column] resonators:

(Experiments 12 and 2)

Does NOT require a stopper at the opposite end.  Instead, the length of the column must be twice as long as the quarter-wavelength version.  

 

The result or sound of this open-ended at both ends column is that it will exhibit "all" harmonics within the tube.  (e.g. if the fundamental or bar's pitch is 100 Hz, then all harmonics of the pitch would be: 100Hz, 200Hz, 300Hzz, 400Hz, etc. within the tube will be heard. "And"..there is an added benefit: Sound is heard from both open ends instead of the single open end just beneath the bar.

 

In order for half-wavelength resonators to match the pitch of the bar they have two distinct differences over the quarter-wavelength column:

(1) they have no tuning stopper and (2) therefore, in order for them to resonate at the bar's pitch, they need to be tuned to the exact pitch by:

 

For a FLAT ring tone: shorten the overall column length by removing some of the length

or

For a SHARP ring tone: lengthen overall column by using some type of an extension collar. 

Resulting Pros and Cons:

  • PROS: (a) Two resonator openings equals louder emerging resonance.  (b) All harmonics sounding result in a more musically resonant tone.

  • CONS: Twice as long resonators can create fit problems under the bars and may/more-than-likely need to expand outside the instrument's envelope.

​​

Note: In marimba building, since everything starts with the bars, their pitch and positioning, rulers and T-squares are used to align the bars to make them visually symmetrical.  From there, after their first tuning, the frame and resonators will be designed to conform and fit to this layout structure. 

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