Real Strobe Tuners Means Extreme Pitch Accuracy

Peterson tuners, having the mechanical rotating disc and flashing bulb displays, are utilized.  These devices are:

  • capable of 1-cent resolution with 0.1 cent (1/10% of a cent) accuracy [1] , and

  • capable of instantaneously showing exact pitch in a fraction of a second.  This means the eye can immediately discern whether the pitch is sharp, flat, or in perfect tune without guess work.


Chris's Tuning Work Station


Mechanical Rotating Disc Strobe:

[Top:] Peterson Model 490 Autostrobe 

[Bottom:] Peterson Model SC5000-II Strobe Center

Pitch Standard
The pitch standard is typically A-440Hz for bass marimbas, marimbas and vibes, and A-442Hz for xylophones and orchestra bells.[2] 

Bars are tuned between 68 and 72-degrees F.  Several readings are taken on the entire bar set throughout the tuning process.  The tuning tolerance is within +1/-0 cents.


[1] The precision required of musical instrument tuning is accomplished by dividing the octave into extremely small divisions called "cents."  There are 1,200 cents per octave or 100 cents per half step (e.g. C to C#, C# to D, etc.).  It is these fractional sub-divisions that the strobe tuner is aligned with and which makes accurate pitch measurement possible.

[2] Why A-440 and why A-442?  The difference in these pitch standards has to do with the ear's ability to perceive higher pitches as being in tune.  Typically, pitches in the higher octaves tend to be heard or perceived as flat.  A-442 is a compensation technique that makes higher register xylophones and orchestra bells sound "more in tune," as well as the ear perceiving these tones as being "brighter" sounding. 

Note: Technically A-442 is about 7 cents sharper than an instruments tuned to A-440.

Bar Tuning Has Limitations

Melodic bar percussion instruments are a limited tuning opportunity.  Unlike a piano, guitar string, or horn, which are capable of endlessly repeatable tunings, bar tuning is not an endlessly repeatable process. There are physical limits that simply cannot be fixed.

First Corrective Tuning
Bar percussion instruments directly from the manufacturer have been professionally tuned and are extremely accurate. If it becomes noticeable that a bar doesn't sound quite right (e.g. slight wavering or beating sound) especially when unison octaves are simultaneously played, this is a sign that the tuning has changed - typically a flattening of its pitch.

Q: Why do bars flatten in pitch? 

A: The internal grain of the bar has been structurally compromised or damaged by some degree.  This means the bar becomes structurally weaker, and has lost some of its restorative or springiness properties.  There are two actions that typically cause this:

1) Using the wrong mallets that are too hard or too heavy for bar's surface and structure.

2) Overly aggressive and heavy-handed playing.


The process of correcting the pitch of an out-of-tune bar, requires material to be removed in specific amounts from specific regions of the bar. 


Raising the pitch back to its original tuning might save the day.  But, the retuning does not fix the internal damage leaving it a little bit weaker. 


First Corrective Retuning

When correcting the pitch of an out-of-tune bar that was previously tuned, just like before the bar requires "additional" material to be removed in specific amounts from specific regions of the bar.  Once the material is removed, the bar will (most likely) be in tune. 


Should the bar flatten from further stresses placed on it (e.g. aggressive heavy-handed playing), subsequent tunings become much more difficult and could even be impossible. 

The Bar's Sound Is At risk

Bars that have been tuned numerous times will lose their ring or sustain time because the internal structure is severely compromised and has lost its restorative properties.  The sound could sound like a "thunk" which is a dead bar.  At this point, replacement becomes the only option.

Quality of the Tuning

When the client receives their tuned bars, the accuracy of the tuning will allow them to take the instrument into a professional musical performance environment  (such as a recording studio or a live orchestral/ensemble performance venue) and have the confidence that the instrument will sound in perfect unison with the other instruments.


CCBANTA Bar tunings are guaranteed for one (1) year from the date of release back to the client.
Guarantee is void when damage to the bar is obvious, such as: dents, scratches, chip-outs, splitting, cracking, and excessive over-exposure to outdoor elements.  Clients will be charged accordingly to bring the bar back to a functional condition (presuming it is still possible to do so) or if it cannot, create a new replacement bar.

I'Mechanical Rotating Disc Strobe Tuners

(Top) Peterson Model 490 Autostrobe

(Bottom) Peterson Model SC 5000-II Strobe Center

Note: The mechanics of the markings on the rotating disc in combination with the flashing light behind the disc create a "wagon wheel effect" or "stroboscopic effect" is an optical illusion in which a spoked wheel appears to rotate differently from its true rotation. The wheel can appear to rotate more slowly than the true rotation, it can appear stationary, or it can appear to rotate in the opposite direction from the true rotation.  The speed of the wheel visually interacted with the film speed rate of 24 frames-per-second will display an instantaneous discernable image.  If the displayed image: moves to the:

Left - the pitch is flat
Right - the pitch is sharp

Stands perfectly still - the pitch is in perfect tune

The wagon-wheel effect (alternatively called stagecoach-wheel effect or stroboscopic effect)

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