Paul Vo, Acoustic Synthesis, and Revolutionary Handpan Sounds

It is still hard for us to believe the sound in the following video is actually coming from the handpan even when we are in the same room as it much less in a video. We have done what we can to show that the sound is in fact coming from the handpan by dropping sand on the vibrating membrane as well as muffling the sound at times. The voice you hear was prerecorded and then driven into the vibration of the note membrane utilizing a magnetic field generated by the device.  The device itself makes no sound. It only creates a silent programmable magnetic field.

All sound is coming from the actual handpan membranes in the video! 

Back Ground on this Project

Mark and Josh have been thoroughly intrigued and excited to collaborate over the past few months with Paul Vo of Vo Inventions.  Paul is a brilliant inventor and product developer who’s work has resulted in the  Moog Guitar, the VO-96 and the VO Wond, which all utilize Paul’s patented vibration control technology to influence and activate the vibrations of ferrous guitar strings.  The popular Ebow is another example of a device based on different technology invented by Greg Heet and patented back in 1979. Paul’s new technology is uniquely capable of controlling individual harmonics of vibration in a predictable way.

Mark and Paul met each other in 2014 at a local musical instrument builders concert in Asheville, North Carolina. They were very curious by each other’s work and discussed the potential of collaboration some day. That day finally arrived in later 2016. After initial discussions between Mark, Paul and Josh about the physics of the Saraz as well as Paul’s other magnetic oscillators, Paul designed and built a prototype magnetic oscillator that is cable of driving the vibration of a handpan.  Currently referred to as the “Saraz Sonic Driver” or “Harmonic Spider”, the device is similar to his other inventions, which are capable of using a programmable magnetic field to activate and drive vibration in ways that are not possible with any other physical force.

We are not the first to use a magnetic oscillator on a handpan. Years after Thomas Rossing’s Holographic Inferometry research on the Hang, we saw Marty of Sunpan use an Ebow like device to activate the fundamental and harmonics on one of his instruments. Similar technology has also been used on an Innersound. What makes our prototype magnetic driver special however is that we are not limited only by activation of the most prominent frequencies within a note such as the fundamental and harmonics. This device is programmable and can actually drive an enormous range of frequencies and complex timbres into the membrane of a handpan.  Paul refers to this technology as “Acoustic Synthesis”, which is taking a digital signal to program a magnetic field that can drive ferrous material vibration.

Basically, the magnetic driver can turn the handpan into a speaker.

While the speaker is limited by the physically possible vibrations of a handpan note membrane, we have discovered to our great surprise that the membrane is in fact capable of far more vibration and complexity than we ever imagined possible even as builders of these instruments.

Paul Vo, Acoustic Synthesis, Harmonic Spider Magnetic Oscillator

After Paul finished the prototype, he came over to Josh Rivera’s studio for the initial demonstration of what it can do.  Within the first hour of Paul’s demonstration, we heard things come from the handpan that we had never imagined including isolated harmonics that are never prominent enough to be heard beyond the underlying timbre of a note.  What was even more surprising and exciting was being able to speak into a microphone and hear our voices come out of the handpan membrane.  We quickly realized that we could drive the device with an enormous array of inputs including other musical instruments, Pro Tools plugins, Ableton Live or even a sound file such as an MP3. This is where Josh’s background in recording engineering become incredibly valuable once again.

Josh, Ableton Live, Magnetic Oscillator and Saraz Handpan

Josh has since clocked dozens of hours exploring what is possible with Pro Tools and more recently with the seemingly limitless options of Ableton Live.  However, he has barely begun to explore what is possible with this novel interaction of a programmable magnetic field driving vibration and therefore sound through a Handpan membrane.  One thing that we find fascinating is how strongly the vibration is driven through the membrane. While we can somewhat muffle the sound, we have never succeeded in completely muffling particularly the higher frequencies even if we cover the entire handpan with a pillow or blanket.

We have also barely begun exploring how to utilize this device on any Handpan much less design a Saraz that is specifically tailored to the device.  It appears that brighter instruments are easier to drive for certain signals but can also have greater distortion while other signals sound better on more controlled instruments.

In the video above, two Saraz were used. Mark’s voice, the Star Wars Theme and John Lennon’s Imagine were recorded on a 21″ diameter C# Minor Saraz that had a relatively controlled center note membrane. We found that we got the clearest signal from this instrument particularly for the prerecorded segments of Mark’s voice. You may have noticed that the driver has two legs on the dimple. We did this in order to further control the particularly active vibration of the long axis.

In the MIDI clip with Josh and Mark, we used a 20″ Diameter F# minor Saraz. For this signal, we found that the driver worked best with all of the legs in the interstitial area around the center note while the driver was placed over one side of the long axis about where Josh drops the sand. This instrument was a bit more bright and seemed to pick up the MIDI signal with more clarity and prominence relative to the more controlled notes that we had available. In this clip, F#4 activates the membrane the most, which Mark plays numerous times on the keyboard. This is the note that gets the sand most excited as the center note is an F#3 with an F#4 octave harmonic on the long axis. When we played the F#4 on the MIDI keyboard, it also strongly activated the side note F#4 as well as the highest C#5 note even though the driver was not near either of those notes. At 3:48-3:49, Josh briefly mutes the side F#4 which is on the far side of the instrument from the camera. This cross activation of multiple notes is likely due to the coupling of the specific instrument. A similar dynamic happens in the beginning of the video when Mark is speaking. The note that he briefly sings to show the activation of the sand is C#4 while the center note is a C#3 with a C#4 octave harmonic on the long axis of the membrane.

In all of the video, the Magnetic Driver is not actually touching the membrane, hence why it has six legs to elevate it above the membrane.  If it touches, it will vibrate against the membrane and rattle. The closer it gets to the membrane however, the stronger the drive and signal due to the magnetic field being closer to the ferrous membrane.

We have also used the device on numerous side notes which of course also activate.  We have also attached the driver to the bottom shell of the instrument and been able to activate all of the notes on the top shell, however it requires much more amplitude than this first prototype device is designed.

We have months of further research to do before even considering if this is a viable commercial product to offer within an already small niche art form. However, this technology has already inspired a lot of creativity and novel ideas that go far beyond sound production.  Even at this early stage of research and design, we have been so astounded by such revolutionary sounds coming from a handpan that we have felt overwhelmingly compelled to share it with the world.  As you might imagine, we will be publishing many more videos of  Saraz being played along with the almost endless signals that can be utilized to drive this magnetic oscillator.

Wishing you all the endless inspiration and imagination,

Mark, Josh and Paul


Tuning Handpans, Hang, and Pantam with Steel Vibration Wave Interference

When first learning to tune, Mark sometimes found that certain notes were impossible to stabilize no matter how perfectly they were in tune. This is a common situation for Singing Steel Tuners that typically happens when different notes share the same frequencies and are in close proximity on the instrument.  It appears that what is happening is wave interference within the vibration of the steel. One note is activating another note, which then reactivates the first note. When both notes start emanating the same frequency in close proximity, there can be an inherent wobble if the two wave forms do not align appropriately.  We have seen this dynamic lead to as little as a 5-8 cent wobble or as much as a 30-40 cent wobble across different builder’s instruments.

phase shift diagram

Some tuners accept a little wobble that many players are unlikely to notice while other tuners detune frequencies to find the best place between stabilization and too far out of tune when this situation occurs.  The dynamic is often stronger and more obvious on material and shaping methods that inherently lead toward greater activation while the dynamic is sometimes weaker on material and shaping methods that lead toward more controlled and muffled instruments. Heat treating recipes, stress relieving, note border and interstitial design can also significantly effect this interaction of vibrating waves.  Within our current building methods, this dynamic has lead us to simply avoid the scenario whenever possible by not offering scales in certain layouts and orienting our notes in certain directions as is common in Steel Pan architecture.

After four years of building the Saraz across multiple materials, shaping methods and designs, we have found that this situation is common in at least four scenarios.

Adjacent Fifth Scale Degrees 

When two notes are aside each other that are a fifth scale degree apart, they will share a similar harmonic if each note is tuned with the typical octave and compound fifth. An example is having an A3 and E4 aside each other as side notes on a handpan. Each note has an E5 harmonic. It is the compound fifth harmonic of the A3 and the octave harmonic of the E4. We have found that about 80% of the time, at least one and sometimes both of these notes will have a slight wobble, specifically due to the harmonics creating wave inference within the vibration of the steel between each note. When the two adjacent notes are lower in the scale, the wobble tends to be 2-4 beats per second while when the two adjacent notes are higher in the scale, the wobble tends to be much faster. This seems to mostly only happen when the two notes are adjacent. If these two notes are across the instrument from each other or have another note between them, the wave interference does not seem to happen nearly as often.

A common scale form that typically has an adjacent fifth scale degree is the Pygmy scale, which is a pentatonic minor scale. Because of this inherent wave inference, we simply do not offer any layouts of the Pygmy scale. While this situation often occurs on pentatonic scales, there are some pentatonic layouts that avoid it.  Although we do not offer the Pygmy scale, we offer numerous hexitonic minor scales that add one additional note positioned so that it eliminates the adjacent fifth scale degree from happening in the layout. This also gives the player one additional note to explore in the minor scale. If the player wishes to play the Pygmy scale, all the player has to do is leave out the additional note of the scale.

Center note harmonics and side notes

Another situation where we have found that wave inference can happen in the vibration of the steel is between the center note harmonics and side notes that share the same frequencies. For example, a G3 center note tuned with a traditional G4 octave harmonic and D5 compound fifth harmonic might create wave interference with the fundamentals of G4 and D5 sides notes. This is much more likely to happen if for example the G4 fundamental side note is near or pointing toward the G4 octave harmonic of the center note.  Similarly, if the D5 fundamental side note is near or pointing at the D5 compound fifth of the center note, wave inference is more likely to happen. The same can also be true with a D4 if it is pointed toward the D5 compound fifth harmonic of the center note because the D4 side note has a D5 octave harmonic.

fine shaping after note pressing

This is the primary reason that we turn certain notes more parallel to the rim of the instrument and away from the center note. These side notes are the notes that also have the same frequency as the center note harmonics. Additionally, we always try to position the center note so that its harmonics are emanating 90 degrees away from the side note with the same frequency. When considering the angle of all emanating frequencies, we tend to position our notes so that similar frequencies are emanating parallel to each other instead of emanating toward each other.  While turning a side note toward the rim takes up far more space, we have found that it is a worthy trade for consistently more wave stability in the sustain of notes that tend to activate each other and lead to wave interference if not positioned in this way.

Shoulder tones and harmonics of side notes

Another place we have found wave interference is between tuned shoulder tones of the center note and harmonics of side notes. This is basically the same dynamic as the other two situations above. Depending on what frequencies the shoulder tones are tuned to and which notes are closest to them, there can be wave interference. An example is a C#3 center note with a C#5 tuned shoulder tone. If there is a C#5 fundamental or a C#4 with an C#5 octave harmonic near the position of the tuned shoulder, it can lead toward wave interference. Of the four examples listed, we find that this situation is the least common, however it does occasionally happen.  At Saraz, we tend to detune our shoulder tones approximately 10-20 cents because when they are perfectly in tune, they tend to scream and sometimes dominate the instrument with a bit more brightness than we desire. This detuning is likely the reason why we do not experience wave interference very often between our tuned shoulder tones and sides notes.

Port tuning of the fundamental

At Saraz, we typically tune the fundamental and two different harmonics into our ports. The other harmonics are typically a third scale degree and a fifth scale degree of the port fundamental, which creates a chord. A common example of a Saraz port tuning is E5 fundamental with G5 and B5 harmonics.  We tend to find generally great wave stability with the port harmonics, however the port fundamental can create significant problems.  The wave form of the port fundamental seems to be a strange animal relative to any other frequency on a Handpan. If there is a note membrane fundamental with the same frequency anywhere on the instrument, it will tend to have horrible wave interference. For example, if the port is tuned with a D5 fundamental and there is a D5 note membrane fundamental any where on the instrument, the note membrane will have wave interference and an inherent wobble that is very noticeable.

Often, the port fundamental also influences other notes with a harmonic that is the same frequency. For example if there is an E5 port fundamental, it will often create a bit of wave interference and wobble on an E4 note with an E5 octave harmonic.  This is often not noticed if the instrument is played in the lap because the player’s legs are muffling the port, however it becomes more noticeable when the instrument is played vertically or put in a stand where the port can freely resonate.  At Saraz, we do not offer any bottom notes with harmonics that share the same frequency as the port fundamental because the wave interference tends to be much stronger than for notes on the top shell. We also often detune the port fundamental approximately 15 cents to decrease the amount of coupling between it and other notes with the same frequency.  Some builders have avoided this dynamic by tuning a port fundamental lower than any note on the instrument. One example is to tune a D3 or Eb3 port fundamental on an instrument where the lowest note membrane is an F3.

Scale Layout Design

People often ask us for scale layouts that we do not offer.  The four scenarios explained above in addition to Resonance Wave Interference are the primary reasons why we only offer certain scale layouts and do not build other scale layouts that we know are likely to lead to inherent wave inference. We feel that avoiding wave interference when possible leads toward an instrument with inherently greater wave stability and therefore higher quality.  All of our Offered Scales are designed with intentional consideration and avoidance of these wave interference dynamics.


Is it a Hang Drum or a Handpan?

Both “Hang Drum” and “Handpan” are very commonly used by players to describe the Saraz and all similar instruments. We have also seen multiple builders use both names to describe their own instruments whether the instruments have tuned membranes or cut tongues. So why do we choose to call the Saraz a “Handpan” instead of a “Hang Drum”?

Much of the answer is within the short history of the two terms.

According to Wikipedia, “the Hang is a musical instrument in the idiophone class created by Felix Rohner and Sabina Schärer in Bern, Switzerland. The name of their company is PANArt Hangbau AG.[3] The Hang is sometimes referred to as a hang drum, but the inventors consider this a misnomer and strongly discourage its use.”

We have heard over the years that one of the reasons that they discourage its use is because it subconsciously leads people to believe that the instrument is a drum like a djembe or a conga and therefore can be played very hard with hands or mallets when the reality is that the tuning of these instruments is not developed to be so sturdy.

Panart has also stated that they consider the Hang to only be made by themselves. The term Hang Drum is basically a Proprietary Eponym. Other builders that have been inspired by the Hang to develop their own instruments were encouraged as soon as they started appearing to use a different name for their own instruments.  One of the first builders to appear was Pantheon Steel. Their tuner, Kyle Cox, coined the name “Handpan” around 2007 as a type of “Steel pan” that is played with the hands. This came about as the moderators of explained Panart’s wishes on the use of the name and that the blog was only for the Hang.   Not long after this point, was created to discuss and explore the new builders that were inspired by the Hang. While has in recent years become primarily an information source about the Hang, remains a forum with a community of thousands of members that explore endless details about established builders, playing, making, and maintaining handpans as well as about gatherings of people that come together to explore these instruments around the world.

We very regularly see Saraz customers post videos of our instruments and call them “Hang Drums” whether we like it or not. We have no choice but to accept that it is ultimately up to the player to call their instruments whatever they want even if the name is not in alignment with our desires and beliefs or those of other companies and enthusiasts. This is especially true in these young days of this art form. A couple other examples include Victor Levinson, who started using the name “Pantam” to describe his own SPB instruments and at least one player, who refers to his SPB and Aciel instruments as “Cupolas”.

It appears very likely that at least the terms “Hang Drum” and “Handpan” are both going to be around for awhile. Perhaps in 100 years, one of these terms will become more commonly used than the other. Until then, we will refer to the Saraz as a Handpan in reverence to the roots of tuned steel in Trinidad and in respect to the inspiration that first sprouted in Switzerland.



Handpan, Hang, Pantam resonance and wave interference

While the Handpan owes much of its development to its parent, the Steel Pan, there are some qualities of the Handpan that are inherently different. One of these qualities is how the two instruments resonate.  

Unlike the Steel Pan, Handpans typically have an additional steel shell glued onto the bottom of the top shell, which creates a resonant chamber.  In many ways, this resonant chamber is part of the magic of the Handpan sound. It also often creates a Helmholtz tone, which does not exist on a Steel Pan. This tone is typically in the range of C2 – G2, which is lower than most handpan notes. On a Saraz, the helmholtz is very often in the range of Eb2-F2 depending on the size of the shell and design of the port. The helmholtz can usually be flattened lower by placing one’s hand over and inside of the port. If the instrument is in one’s lap, the helmholtz can be changed by adjusting one’s legs to let a specific amount of air flow into the port.


helmhotlz formula and diagram


One of the negative side effects of the typical handpan chamber is that it also creates a resonance problem with specific frequencies. While some people have referred to this as an “impedance” issue, it is perhaps more appropriately called “wave interference”, ”Phase Cancellation”, or Phase Shift”.


phase shift diagram


A number of variables influence this wave interference.  Chamber height, port depth and especially chamber diameter have a significant influence on the equation because of their reflective quality. Simply put, each sound wave is bouncing off of the chamber and specific frequencies have just the right wave length to create wave interference as they reflect back from the steel and do not align with the same frequency still coming directly from a note membrane. While differences in chamber height and port depth can shift the range of these frequencies slightly, chamber diameter is by far the most influential variable.  At Saraz, we built 21 inch / 53.34 cm diameter instruments until early 2016.  On this size shell, Bb4 has the most intense wave interference in our note range, particularly as a fundamental of a note. No matter how well the note is tuned, there is typically about 20-50 cents of wobble in the sustain of the note. Bb4 harmonics such as the compound fifth of an Eb3 or Octave of a Bb3 also wobble around 5-25 cents in the sustain of the note. Covering the port with one’s legs or placing the instrument in a stand can also affect the intensity of this wave instability.

Additionally, air temperature and elevation influence wave interference. This is because the air pressure within the chamber is affected by temperature and elevation, which in turn changes the length of each sound wave. A great example is a note just on the edge of a wave interference range such as A4 on a 21 inch diameter chamber. At about 80 degree F / 27 C, an A4 note typically sounds pretty good if the note is positioned well on the instrument. However, below about 60 degrees F / 16 C, the wave interference often becomes more audible. Even colder and it usually becomes even more obvious. Part of this appears to be due to the note sharpening further toward the peak of the wave interference range at cooler temperatures while some of it is due to the change in wave length of the note frequency.

We spent years trying to over come wave interference on our 21 inch shell. A small piece of open cell foam will often help, however this is only because it is muffling the frequency along with many other frequencies on the instrument because it is absorbing the sound instead of allowing it to continue reflecting.  We found after many experiments that closed cell foam and neoprene are better options because they reflect more of the sound waves instead of absorbing them, however they still muffle the instrument somewhat. We have seen other builders use a piece of thin aluminum glued into the chamber to create a new point of reflection with some success.  With each of these “baffling” methods, there is often a very specific position that is most effective, however rarely does it completely stabilize the wave interference because the sound waves are still bouncing all around the chamber.

For these reasons and in pursuit of higher quality, we took a new direction with the Saraz in early 2016. We radically changed our offered scale list to exempt the worst ranges of wave interference on our original 21 inch instrument while also developing two new sizes of Saraz handpans to explore previously uncharted territory with much more inherently stable chamber resonance than previously possible on our original size instrument.


19", 20" and 21" diameter Saraz handpans


In 2016, we gathered a lot data about wave interference across our three sizes of instruments. We often discuss  wave interference within “primary” and “secondary” wave interference ranges because there is more than just one range on any particular size chamber and each range varies greatly in its intensity.

We consider the primary range on each chamber size to be the main frequency in our note range that has the most wave interference. The range appears to extend at least 150 cents when the frequency is the fundamental of a note so there are usually two fundamental notes that are affected.  They are as follows:

19 inch/48.26 cm – C5 is closest to the peak wave interference while B4 is also affected.

20 inch/50.8 cm – B4 is closest to the peak wave interference while Bb4 is also affected.

21 inch/53.34 cm – Bb4 is closest to the peak wave interference while A4 is also affected.

We no longer offer any of these notes as a fundamental on each of these size Saraz. We also do not offer notes with an octave harmonic or compound fifth that is the frequency closest to the peak wave interference on each size chamber.  For example, on our original 21 inch diameter Saraz, we no longer offer Eb3, Bb3, Bb4 or A4 notes.

As an octave or compound fifth harmonic, the range of wave interference is smaller  than as a fundamental so the second note listed by each chamber size is usually more stable as a harmonic. For example, Bb4 wobbles on a 21 inch diameter chamber as a fundamental, octave or compound fifth while A4 wobbles mostly as a fundamental and specifically at colder temperatures. A4 is mostly stable as an octave or compound fifth harmonic on a 21 inch diameter chamber however it will begin to wobble audibly if it is only 10-15 cents sharp of standard tuning.

While the primary range is the most audible, the secondary ranges are considerably more subtle and often completely inaudible. The secondary wave interference ranges also appear to be smaller on each size chamber probably because we do not tune fundamentals in their higher frequency range. These frequencies tend to wobble about 3-12 cents and can often be stabilized without much negative affect to the instrument by using a very small piece of closed cell foam  or neoprene “baffling” in the correct position near the rim of the inner chamber.

19 inch/ 48.26 cm – G#5 and sometimes A#5, C#6 and D#6

20 inch / 50.8 cm – G5 and sometimes A5, C6 and D6

21 inch / 53.34 cm – F#5 and sometimes G#5, B5 and C#6

The first note listed for each chamber size typically has 5-12 cents of instability without baffling on every instrument while the other three notes listed for each size are a bit unpredictable. They may have up to 5-8 cents of instability on some instruments and absolute stability on other instruments. Perhaps this is due to the angle and position of the note membrane as well as other variables like differences in chamber height, port depth, and air temperature when we gathered this data. Either way, we consider these frequencies to have acceptable wave interference that is much more subtle and inaudible relative to the intensity of primary wave interference ranges so we still offer all of these frequencies on each size chamber.

For perspective, very few people can hear within 5-10 cents of tuning deviation, however an oscillating wave is a bit more audible. Less than this range may appear as a slight wave in the sustain that might oscillate 1-3 times in 5-7 seconds of sustain or it may not oscillate at all. Many tuners purposely “stretch octaves” or detune notes because perfectly standard tuning has a sterile sound due to imperfect wave alignment and also because coupling increases as the sound waves become more perfectly aligned. When one dives into the fine details of true wave alignment, one will find that frequencies such as a major or minor second scale degree align at 4 cents sharp of standard tuning while other scale degrees align better at 2, 6, or even 17 cents from standard tuning.  At this level of detail, the art of tuning and the preferences of the tuner become increasingly more influential on the sound. As players and builders, we feel that all of the secondary ranges are within this gray area of tuning style and signature.

In summary, wave interference is extremely common on MANY handpans from MANY makers. A  small percentage of handpans made have 100% completely stable resonance unless they avoid at least all of the listed frequencies in the primary wave interference range. Even then, there are other inherent building complications, which we will discuss in other posts, that may make a frequency unstable. Whether one calls it “impedance”, “phase shift”, “wave cancellation” or “wave interference”, it is one of the many inherent complications in building handpans that can have a noticeable effect on the sound and quality of a specific instrument.



B Sharp, E Sharp, C Flat and F Flat

c sharp mixolydian mode on treble clef

About once per month, we have a considerate visitor to our website write to inform us about typos in the list of notes on our scale list. The most popular scales that receive this attention are C# Mixolydian, F# Major, and F# Harmonic Minor because these scales contain an E#.  

Most people with a basic understanding of music know that the black keys on a piano are considered the “sharp” and “flat” keys. They also know that there are two pairs of white keys on a piano that do not have a black key in between them. These two pairs are B / C and E / F. 

So E#?  Isn’t that simply an F? Indeed, it is the same frequency.

So why would one write it as an E#?  

When properly writing scales, the same letter is never used twice.  For example, in the scale of C# Mixolydian, the scale is properly written with an E# and F#. For this reason, the “F” note is known as E#. The same is true in F# Major and F# Harmonic Minor, which both have a major 7th scale degree, known as E#.

In time, we will release a C# major scale with a B# and E# as well as a Eb minor scale with a Cb note 😉 

A great source that we regularly use for referencing scales is

Hammer shaped Saraz

Metal sheet before shaping a shell while making a Saraz Handpan

Handpan Shell Forming Methods

The handpan art form has been developing exponentially quicker as more and more people are starting to explore tuned steel. This is leading to novel building ideas being released to the public almost weekly. One topic of development has been basic shell forming. Whereas the steel pan has been traditionally hammered or “sank”, the birth of the handpan arrived on Deep Drawn shells. Years later, Jim Dusin and Kyle Cox of Pantheon Steel developed a new forming process called “Rolling”. While it is similar to traditional metal spinning (that some handpan builders have also used), there are fundamental differences in the Rotations Per Minute as well as how the shell is held and formed.  In 2015, the Deep Drawn shell became increasingly popular after Shellopan lead a cooperative project to produce the shells and sell them to dozens of other builders. In 2016, Colin Foulke popularized another traditional metal forming process called Hydro forming. Numerous more builders began using the method after Colin shared his Machinery Design. The only other method that we have heard of that we have not seen used is “Single Point Incremental Forming”, which is referred to by Soren Maloney in at least one of his Academic Papers (note that the paper will immediately begin downloading to your computer when you click on the link). 

At Saraz, we have explored a few of these methods. While we have mostly built fully hammer shaped instruments, we were one of the first builders beyond Pantheon Steel to explore the Rolled Shell. Here is a video of the most recent Rolled Shell Saraz built in 2016.

Once Shellopan began offering Deep Drawn shells, we also explored some of those. The following video is a Saraz built on a Shellopan shell:

We have also explored a couple Deep Drawn shells from Isthmus Instruments.  Here is the most recent Saraz built from one of those shells:

While we have never built a Saraz from a Hydro formed shell, Mark recently tuned a note on another builder’s hydro formed shell while giving a building lesson and found the experience quite interesting, insightful and confirming of his hypotheses about the material particularly in regards to the thickness profile.

With so many potential building methods, we are sometimes asked why do we choose to continue focusing on fully hammer shaped shells?

While we don’t believe that the hammer shaped shell is the best option or even better than other shell forming options that we have explored, there are a number of reasons why we choose to focus on hammer shaped shells. 

The first reason is because we can. While we have found that sinking shells is one of the easier skills to learn in the process of building a handpan, our method has required at least 20-30 shells to get good at sinking a shell smoothly and most importantly with an ideal stretch (with an experienced teacher). Figuring out on our own how to sink an ideal shell for our process and preferences took us at least 200-300 shells. While it is much easier using a pneumatic hammer than hammering a shell entirely by hand, it is still a physically intensive job, especially compared to pushing a button on a machine that does it for you. With a focus on shell independence and an appreciation for the tone and timbre of hammer sunk shells, Mark has rarely considered trying to entirely bypass sinking shells by hammer. His interest in using other materials has primarily come from a curiosity to learn more about the handpan building process and the nature of tuned steel by trying new methods. For this reason mainly, he developed a team of people to contribute to the workload necessary for building and developing the Saraz. In the 4 years that the Saraz has been in production, 7 people have been trained to sink shells. While the process evolved in different directions through the hard earned lessons of a couple people, Mark’s father, Papa Steve, deserves most of the credit for developing the current shell sinking process at Saraz. It is important to realize that had Mark been building the Saraz alone for the last 4 years, it would not have evolved in the way it has and he would definitely not be using hammer shaped shells as the process would have been simply too brutal for him to do in addition to shaping dimples, forming ports, and tuning. 

While we CAN sink shells as a team, there are other more important reasons that we CHOOSE to still focus on hammer sunk shells.  The main reasons are because of the nature of the material as well as its tone and timbre.

We have developed a process that leads toward a thickness profile which we prefer as well as note architecture based around this thickness profile. The center of a Saraz shell receives the least hammer strikes in order to keep it as thick as possible while most of the stretch is in a ring around the center note. This area is approximately between 5 inches/12 cm from the center point of the shell and 4 inches/ 10 cm from the rim. Near the rim on a hammered Saraz shell  is the thickest while the next thickest place is the center of the shell.


Tuned steel notes are similar in many ways to tuned strings. Lower notes want thicker strings to vibrate appropriately while higher notes want thinner strings to vibrate appropriately. Consider the thickness of different guitar strings as an example. Panyard, one of the finest Steel Pan builders in the world, grinds down the thickness of every note on their instruments to their ideal thickness for this reason.

Relative to other forming methods, we have found that the center of our hammer shaped shells is a similar thickness to that of the rolled shells that Pantheon once sold, which were formed on the same thickness of metal (approximately 1.2 mm thick).  The center of a Hammered Saraz shell is thicker however than the center of a 1 mm Shellopan Deep Drawn shell. The center of a hammered Saraz shells is also thicker than the Hydro formed shells that we have seen formed from 1.2 mm thick steel.  With the traditional layout of a handpan having the lowest note in the center, this is very important! Compare this to a traditional steel pan where the lowest notes are typically near the rim while the highest notes are in the center.

Our hammer sunk shells are also slightly thinner in the ring of primary stretch than a Deep Drawn shell and much thinner than some of same area on the Hydro formed shells that we have seen, however our hammer sunk shells are thicker than the same areas on a rolled shell. Each of these deviations leads toward a desire for different ideal note size. For example, the note form that we use for E4 on a hammer shaped shell is one note larger than the note form that we use for E4 on a rolled shell. This is because thicker metal seems to inherently lead toward bigger notes while thinner metal inherently leads toward smaller notes. While there are some ways to compensate for this, we are speaking about generalized inherent nature. Because of the thickness profile, fully hammer shaped center notes on a Saraz tend to be stronger and stiffer than on a Deep Drawn Saraz, which are very easily bendable. The highest harmonic partials such as G#6 or A6 (the compound 5ths of C#5 and D5) are a bit easier to make sing on hammer shaped Saraz than on Deep Drawn Saraz while they are the easiest to make sing on a Rolled shell Saraz. This is not to say that beautiful instruments can not be made on shells from other forming methods as multiple builders have achieved it on each forming method. It is only to explain how and why we have designed our architecture around the hammered shell method. 

Beyond thickness profile, another reason that we prefer hammer shaped shells is because of the inherent nature of the tone and timbre. While much of this equation is enormously influenced by heat treating, metal alloy, and especially architecture, there are inherent qualities to the hammer sunk shell that appear somewhat universal. Particularly, hammered shells appear to have a nice and balanced degree of coupling or note activation,at least for our particular taste as players. It is very common for lower notes to activate higher notes. For example, a B3 might activate a B4 on the other side of the instrument because they share the same frequency (B4). Sometimes, a high note might also activate a lower note in the same way. Controlling the degree of this coupling is the only reason why we turn some notes more parallel to the rim (particularly notes that share the same frequencies as the center note). In comparison, there is much less coupling on a Deep Drawn Saraz or on the hydro formed instruments that we have seen.  

We would never proclaim that either shell or quality is better or worse. It is simply a matter of preference and personal taste. Some players and builders prefer less activation while we prefer a bit more.  There is a limit however to how much we prefer. When we were building predominantly Rolled shell Saraz, our architecture and building process of the time lead to much greater coupling to a point that we sometimes did not prefer. While the Halo has developed in ways that tame this variable considerably resulting in a beautiful balanced instrument, there seems to be an inherent quality of strong coupling with the Rolled forming process.  We particularly found this to be true with bottom notes on rolled shells.

Another interesting quality of comparison between forming methods is note isolation. While we prefer just the right amount of coupling, we also want the best note isolation possible between adjacent notes. While it is nice to have 10, 11, or even 12 notes on a top shell, it becomes increasingly more difficult to achieve excellent isolation with every instrument. This is what is most impressive in the instruments of builders that have achieved it! Of the forming processes that we have explored, we have found that the hammered shell has the most inherent isolation for our building methods and architecture. While of course great isolation can be achieved on a Rolled shell (as Pantheon Steel and Symphonic Steel have shown countless times) and on a Deep Drawn shell (as Echo Sound Sculptures has shown countless time), we have found that with our own hammer shaped instruments, it is slightly more consistent and easier to achieve than on our rolled and deep drawn instruments.

Two other qualities worth mentioning are sustain and brightness. Again these are very strongly influenced by the alloy, heat treatment and note architecture, however we find there is a bit more inherent sustain as well as brightness on a hammered shell than on a Deep Drawn or Hydro formed shell. On the other hand, there is less inherent sustain and brightness on a hammered shell than on a Rolled shell.  While the brightness of high frequency amplitude can be strongly influenced by stress relieving a hammered shell, we have found it a bit more difficult to increase on the more “ceramic” nature of the Deep Drawn shells without compensating some of the rust resistance. Conversely, we have found that the same quality can be difficult to harness and control with our building methods on a Rolled shell without addressing the issue through architecture or heat treatment.

In summary, we would like to clarify that we do not feel that a hammer shaped shell is the best or even better than other shells or anyone else’s process.

The intention of these explanations are to elaborate on why WE currently prefer to focus on the hammered shell as builders and as players. Not everyone feels the same about these qualities as we do. Everyone’s building process is at least a little different, which leads to different inherent qualities. We feel that this is great because it leads to a diversity of tones, timbres and instruments in the world. This diversity of preference also leads some builders toward “thinking outside of the box” and exploring completely new ideas. When is someone going to use a “Single Point Incremental Formed” shell to build a Handpan? How about it Soren? We would love to explore one if we had the opportunity because with each different material and forming method, we learn something new about the nature of vibrating tuned steel membranes.

In a time when a recent and growing majority of builders are utilizing Deep Drawn and Hydro formed shells, one main reason that the Saraz sounds unique among the art form is because of the primary shaping process. We will however continue to explore and build instruments on different materials. We still have some Rolled shells as well as Deep Drawn shells from both mentioned fabricators in our stock that will one day become Saraz. We also look greatly forward to the next step of exploration and development in this young art form as it will inevitably reveal new secrets about the internal structure of vibrating tuned steel membranes.

With much respect to all builders

-The Saraz Crew

Hammer shaped Saraz shell after forming

Saraz on Deep Drawn Shellopan shells

shellopan handpan shell thickness profile batch 1
In early 2016, we began exploring a third material and forming method. Along with fully hammer shaped shells formed in our shop and rolled shells fabricated by the late Jim Dusin of Pantheon Steel, we began building limited edition Saraz on deep drawn shells fabricated by Shellopan in France.  We were perhaps the 15th or 20th Handpan / Pantam builder to make instruments on these shells with most other builders that use them currently residing in Europe.  We have tremendous respect and gratitude for Shellopan making these shells available to other builders. Along with the spread of knowledge about how to use these shells,  it has become much easier for many more people to make handpans with a tiny fraction of the amount of time and effort that it took earlier builders to learn this knowledge on their own. We couldn’t be happier to see so many new handpan builders getting started because they are helping to satiate a bit more of the extensive international demand for handpans as well as co-creatively pushing the evolution of the artform forward faster than ever before.

The Shellopan deep drawn shell has been an interesting material that has revealed to us a few new insights into the internal structure of the steel. While perhaps the shell’s greatest virtue is eliminating the need to sink a shell, we have found yet again how the initial forming process can dramatically change the nature of the material as well as the tone and timbre of the instrument. The shell offers a bit more inherent ceramic or “Pantam” tone and timbre relative to a fully hammer shaped shell or a rolled shell. The stretch and thickness profile is very appropriate for the traditional handpan layout while the overall shape is nearly perfect. On the Shellopan website “Fablab” page, they discuss many of the characteristics of the shell as well as compare it to other forming methods such as hammered, spun, rolled, and hydro formed shells while discussing some of the pros and cons of each.

We have a few more Shellopan deep drawn shells in stock and will continue to build limited edition Saraz on them well into 2017 and maybe longer.  Most of those instruments will likely be flash sales on our website.

The following video links are a few of the Saraz that we have made with Shellopan shells in 2016. Big thanks again to Delphine and Matthieu for sharing their developments with the world!