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MARIMBA TUNING

Case Studies

The following are examples of repairs I have performed.  When problems arise, every aspect of the instrument's components (bars, resonators, and/or its frame) must be thoroughly scrutinized so a repair solution can be formulated.

No. 1 - Worn Finish

Instrument type: Musser "Kelon" synthetic bar* marimba

Problem: Incredible amount of mallet damage.  Miraculously, this instrument had maintained its tuning and there was no buzzing anywhere within the range of these bars - a wonderful advantage of synthetic bars.

Most-Likely Cause:  Excessive force and abusive mallet strikes, and most-likely the use of much harder mallets.  Some bars actually had lengthwise cracks and yet maintained their tuned pitch.

Solution: "Kelon" is Musser's tradename for their synthetic bars.  Due to the resilient nature of these bars they received a simple sanding, a spray coat of black primer followed by two coats of black satin finish, and a full tuning check.

*Note: Synthetic bars are actually an engineered composite material that  is extremely robust and can take punishing abuse.  Other bar percussion manufacturers have similar synthetic bars in their instrument line ups, which offer a highly durable alternative over that of their organic wooden counterparts.    

No. 2 - Sun-bleached Finish

Instrument type: A 4-1/3 octave marimba with African Padauk bars

Problem: 1) Sun bleached bars causing the bar's natural hue to gray out. 2) Some bars were damage so their tone affected.

Most-Likely Cause:  1) This is what happens when African Padauk is repeatedly exposed to direct sunlight. 2) Damaged bar were subjected to excessive force. 

Solution: This repair was tricky because it required a gradual sanding-off the bleached wood so fresh wood could be exposed.  The danger is, if too much of the surface is removed it could cause the bar to go so flat that it's pitch cannot be brought back. In some cases this happened and new bars had to be fabricated.  New bars were also fabricated to replace the damaged bars.  Due to the drastic nature of this repair,  the owner was cautioned that this instrument had to be played very conservatively and with a heightened level of respect as to not risk a re-flattening of the pitches.  If aggressively played, several of the bars or possibly the entire bar set would eventually need to be replaced.    

No. 3 - Crack in Bar

Instrument type: Zimbabwean (large-scale) bass marimba

Problem: The two lowest (and largest) bars had developed length-wise cracks in the middle section.

Most-Likely Cause:  Zimbabwean music is known for its lively and aggressive playing - which makes it sound so dynamic and fun.  Marimba players tend to be a bit heavy-handed at times to keep the energy flowing.  Furthermore, the bar's strike zone is at the thinnest part of the bar making it prone to [potential] damage.

Solution: Since a mid-bar crack is in a high pressure strike zone, it cannot be successfully joined together with a heavy-duty adhesive or epoxy.  Even if appearing to be fixed, continued mallet strikes will inevitably cause the crack to reopen.  Therefore, two new bars were fabricated using the sizing of the damaged bars.  In this case, hard maple was the wood of choice due to its strength and resistance to breakage.

No. 4 - Broken and other Damaged Bars

Instrument type: Xylo-Marimba

Problem: Many of the bars had cracks, were so dead they didn't sustain, were extremely flat in their pitch, and the worst was a bar that had broke into two pieces.

Most-Likely Cause:  This a clear case of excessive pounding and force on the bars, and probably use of the wrong mallets.

Solution: No bar in this scenario could be salvaged or repaired.  All new bars had to be fabricated.  In this case, the customer was not concerned that the new bars did not match the hue of the existing bars - he just wanted a fully functional marimba. 

Bar Percussion Instrument Problems and Modifications

The following are examples of repairs and modifications I have performed.  When problems arise, every aspect of the instrument's components (bars, resonators, and frame) must be thoroughly scrutinized so a repair solution can be formulated.

No. 1 - Worn Finish

Instrument type: Musser "Kelon" synthetic bar* marimba

*Note: Synthetic bars are actually an engineered composite material that is extremely robust and can take punishing abuse.  Other bar percussion manufacturers have similar synthetic bars in their instrument line ups, which offer a highly durable alternative over that of their organic wooden counterparts.   

Problem: Incredible amount of mallet damage. 

Note: Miraculously, this instrument had maintained its tuning and there was no buzzing anywhere within the range of these bars - a wonderful advantage of synthetic bars.

Most-Likely Cause:  Excessive force and abusive mallet strikes, and most-likely the use of much harder mallets.  Some bars actually had lengthwise cracks and yet miraculously maintained their tuned pitch. 

Note: Although holding their pitch while being cracked, continued hard playing might possibly introduce a buzzing sound in the future.

Corrective Action / Assessment Solution: "Kelon" is Musser's tradename for their synthetic bars.  Due to the resilient nature of these bars they received a simple sanding, a spray coat of black primer followed by two coats of black satin finish, and a full tuning check.

 

No. 2 - Sun-Bleached Finish

Instrument type: A 4-1/3 octave marimba with African Padauk bars

Problem: 1) Sun bleached bars causing the bar's natural hue to gray out. 2) Some bars were damage so their tone affected.

Most-Likely Cause:  1) This is what happens when African Padauk is exposed repeatedly to direct sunlight. 2) Damaged bars were subjected to excessive force. 

Corrective Action / Assessment Solution: This repair was tricky because it required a gradual sanding-off the bleached wood so fresh wood could be exposed.  The danger is, if too much of the surface is removed it could cause the bar to go so flat that it's intended pitch cannot be restored. In some cases this happened and new bars had to be fabricated.  New bars were also fabricated to replace the damaged bars.  Due to the drastic nature of this repair, the owner was cautioned that this instrument had to be played very conservatively and with a heightened sense of respect as to not risk a re-flattening of the pitches.  If aggressively played, several of the bars or possibly the entire bar set would eventually need to be replaced - a very costly prospect.    

No. 3 - Crack in Bar

Instrument type: Zimbabwean Marimba Band (large-scale) bass marimba

Problem: The two lowest (and largest) bars had developed length-wise cracks in the middle section.

Most-Likely Cause:  Zimbabwean music is known for its lively and aggressive playing - which makes its sound so dynamic and fun.  Marimba players tend to be a bit heavy-handed at times to keep the energy flowing.  Furthermore, the bar's strike zone is at the thinnest part of the bar making it prone to [potential] damage.

Corrective Action / Assessment Solution: Since a mid-bar crack is in a high pressure strike zone, it cannot be successfully joined together with a heavy-duty adhesive or epoxy.  Even if appearing to be fixed, continued mallet strikes will inevitably cause the crack to reopen.  Therefore, two new bars were fabricated exactly matching the size of the damaged bars.  In this case, hard maple was the wood of choice due to its strength and resistance to breakage.

No. 4 - Broken and other Damaged Bars

Instrument type: Xylo-Marimba

Problem: Many of the bars had cracks, were so dead they didn't sustain, were extremely flat in their pitch, and the worst was a bar that had broke into two pieces.

Most-Likely Cause:  This a clear case of excessive pounding and force on the bars, and clearly the use of the wrong mallets.

Corrective Action / Assessment Solution:

1) No bar in this scenario could be salvaged or repaired. 

2) All new bars had to be fabricated. 

3) In this case, the customer was not concerned that the new bars did not match the hue of the existing bars - he just wanted a fully functional marimba. 

No. 5 - Broken Cord

Instrument type: Pentatonic D-Major Scale Marimba for Children

Problem: Cord broke

Most-Likely Cause:  Children tend to strike the bar at the cord suspension point rather than the middle of the bar.  This puts downward pressure on the cord against the stand-off.  Over time the cord is abraded and eventually breaks.

Corrective Action / Assessment Solution:

The bars were unstrung from the resonator box. 

Some additional spacing was added to each bar's hole location so they wouldn't bind on the stand-offs. 

A bar tuning check was performed, a new cord was added, and a quick spray wax wipe down did the trick.

No. 6 - Very Old Steel Bar Set without a Frame

Instrument type: A 1914 Deagan Steel Bar "Wholetone" Scale

Problem: The original supporting frame had most-likely worn-out and deteriorated over the years.

Most-Likely Cause:  Time and age?

Corrective Action / Assessment Solution: 

1) Check tuning and correct as needed)

2) Buff and clean-up bars

3) Design a new frame to support and contain these beautifully sounding tones.

No. 7 - Another Very Old Steel Bar Set without a Frame

Instrument type: A 1914 Deagan Steel Bar "Wholetone" Scale (More than likely a half-step in-between notes companion from the instrument above.)

Problem: The original supporting frame had most-likely worn-out and deteriorated over the years.

Most-Likely Cause:  Time and age?

Corrective Action / Assessment Solution: 

Same corrections as No. 6 above, along with new extension lengths added to the bottom two resonators.

No. 8 - Quarter-tone Pitches Inserted into the Accidentals Blank Spaces

Instrument type: Yamaha 4-1/2 octave Marimba with Rosewood Bars

Requested Modification:  Customer desired to add quarter-tone pitches into the empty spaces on the accidentals row.

Most-Likely Cause: [Not Applicable]

Corrective Action / Assessment Solution:

1) Determine the actual frequency of each [new] quartertone pitch fitting into the open space.

2) Using the sizing of the existing surrounding notes, determine the length and width of each bar.

3) Using the straight-line edge of the front-facing bars and the back-end profile of the same bars, determine a matching length that follows a continuous straight line of the accidentals facing edge.

4) Fabricate new bars to fit the profile of the neighboring notes and follow the suspension cord line into the new bars.

5) Rough tune each bar to match the quarter-tone designated pitch of the would-be bar's new position.

6) Sand, drill the mounting holes, and clear coat each new bar to match the coating of the neighboring bars.

7) Fabricate airtight stoppers for insertion into the dummy resonator tubes.

8) Final tune the new bars and their corresponding resonators to match the quarter-tone pitch.

9) With the new bars sitting on foam, check each new pitch using a strobe tuner for resonance quality that matches that of the neighboring note.

10) Restring the new bars into the accidentals notes along with the original/neighboring notes.  11) test all pitches for tonal consistency with all other bars.

No. 9 - Retuned Gourd Marimba (Balaphone) and Electronification Added

Instrument type: An original hand-made marimba with gourd resonators. 

Note: This instrument belongs to Danny Elfman and was originally used on a song called

"Grey Matter" during his earlier Oingo-Boingo days.

05c0bd-20190923-danny-elfman-72.jpg

Requested Upgrade: (A) Retune bars down one full step, (B) Install piezo-electric transducers on each bar for amplification assistance. 

Corrective Action / Assessment Solution: 

1) Remove all bars from frame

2) Prepare a piezo contact area where the piezo transducer can firmly sense the bar's vibration.

3) Retune all bars by flattening pitch down one whole step - but leaving them 25 cents sharp of their new destiny pitch.  This is to account for any affect the piezo has when mounted in place.  (Note: It is always a safe practice leave the bars sharp of their destiny pitch.) 

4) Securely mount the piezo transducer at the prepared node-point location.

5) Final tune all bars to bring them into their (new) destiny pitch at the 442.0Hz pitch standard.. 

6) Replace the old steel wire frame with a new folding frame

7) Fabricate a roll-around base unit with casters to assist in moving the entire instrument

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