Microphones:

Electroacoustic Harp vs Amplified Acoustic Harp


The harp comes in various shapes, sizes and colours. There are concert pedal harps, as well as smaller harps called Lever or Celtic harps. And, over the years, there are also different ways that harp builders have made electroacoustic harps and electric harps. 


Acoustic harp: a pedal or lever harp that sounds acoustically

Electric harp: a harp that only sounds when amplified

Electroacoustic harp: a harp that can be played acoustically as well as amplified.


I will be focusing my attention on the pedal harps currently on the market, since this is what the Stellar Sonata is written for and thus most relevant for the research. Those are electroacoustic harps, since the only fully electric harps that exist are level harps only. 


The first question that comes up for adapting the Stellar Sonata for an acoustic harp is: how do I amplify an acoustic harp? Before that it’s useful to consider what type of electroacoustic harps exist in order to know what one should be trying to recreate. 


                                  Electroacoustic Harps

To start, here are some general characteristics of the electroacoustic harp. Designed for both acoustic and amplified performances, these harps like other concert harps feature 47 strings, each equipped with individual piezoelectric pickups to capture and project the sound of the harp with clarity and balance. The pickups have a wide range in frequency response (20 Hz – 20 kHz) and a high signal-to-noise ratio (>80 dB), ensuring precise amplification without distortion. This system allows harpists to perform in larger venues or with ensembles while maintaining the instrument’s natural tone. The system includes an active preamp for impedance matching, gain control, and output via balanced XLR or 1/4" jacks, often with built-in EQ and phantom power compatibility. Unlike traditional microphone setups, this design minimizes feedback and external noise, making it ideal for live performances, studio recordings, and integration with effects processors or MIDI systems.

Camac Big Blue 47


The Big Blue is an electroacoustic harp model by French harp builder Camac. This is the harp that the Stellar Sonata was written on and for. 

Camac has been a pioneer in electric and electroacoustic harp innovation, with its first model being released as early as the 1980s, continuously pushing the boundaries of amplified harp technology. Founded in France, the company developed one of the first fully electric harps, which was a lever harp called Camac Blue Harp. Not long after that, the development and production of more electric as well as electroacoustic harps continued, with the Camac Big Blue being presented for the first time at the World Harp Congress in Paris in 1990.1

 

The Big Blue uses microphone pick-ups on every string, 47 to be exact. The harp has four outputs: one for each register (high, middle and bass) and one for the pick-ups. The two pick-ups are situated inside the soundboard, one on the higher end of the sound board and one on the lower. These pick-ups are for amplifying more percussive sounds. They don’t really pick up on the actual sounds produced on the strings, only that of the soundboard. 

On the bridge of the harp, in the middle of the soundboard, a small metal part at 2 can be taken out in different places, allowing the pick-ups to be divided into different registers: the bass, middle and high register. This design is unique to the brand of Camac and is used by Caroline Lizotte for her Stellar Sonata. This will be one of the requirements to pay attention to when recreating the set-up, in both the microphones and the Ableton effects. Lizotte chose this harp because she had the oppotunity to try it out at the World Harp Congress in 2008. She fell in love with this model and decided to order one for herself in the iconic chrome colour.

Camac Jubilée


The other electro-acoustic harp that’s currently on the market by Camac, is their 50th anniversary model Jubilée, which the brand announced at the World Harp Congress of 2022, on which Caroline Lizotte performed her recital of the Stellar Sonata. The logistics and details of the harp are generally the same, but the design is quite eye-capturing. 


Salvi Rainbow and Electra

Salvi Harps has played a key role in electric and electro-acoustic harp innovation since the mid-20th century. In 1974, they introduced one of the first solid-body electric pedal harps, featuring an aluminium core for stability and enhanced amplification. This advancement allowed harpists to perform with greater volume and clarity while preserving the instrument’s traditional aesthetic. Salvi's commitment to blending traditional craftsmanship with modern technology has solidified their reputation as a premier harp manufacturer.2

The electro-acoustic model by Salvi is relatively similar to the ones from Camac. It has a microphone pick-up on every string, and it also uses a pick-up on the soundboard, but only 1 compared to the 2 of Camac, and it is situated on the outside of the soundbox not on the inside. The biggest difference is that the harp only has 1 output, and no metal bridge can be taken out, so there is no possibility to let the registers function individually. In that sense this electro-acoustic harp model is slightly more limited than the Big Blue from Camac.  The biggest difference is that where the Camac harps feature multiple output channels, allowing for stereo sound or individual string processing, Salvi’s system provides balanced and unbalanced output. This means that Salvi does not immediately have the same control over the registers as the Camac does. 

Salvi harps tend to emphasize a more natural, resonant tone, ideal for classical and acoustic settings, while Camac harps are designed for versatility, making them well-suited for amplified and effects-driven performances. Both brands offer high-quality electro-acoustic harps, but Camac leans more toward innovation in amplification and signal processing, while Salvi prioritizes maintaining the traditional harp sound with added flexibility.

 

Lyon and Healy Style 2000

Design of a style 100

 

The Lyon & Healy Style 2000 Electroacoustic Harp was developed in the early 1980s, making it the first pedal harp with an integrated pickup system. This harp has the same design and built as their taditional Style 100. Once again, a similar design to the other electroacoustic harp models, with pickups on all 47 strings. Unlike the models from Salvi and Camac, which incorporate additional soundboard pickups to capture the resonance of the soundboard, the Style 2000 focuses solely on string transducers. This design emphasizes direct string amplification, aiming to preserve the harp's natural acoustic tone without additional soundboard input. It is therefore more used for amplification only, rather than exploring innovative practices of sound processing and the use of effects.3 

                                          Microphones

The goal of this research is to adapt the Stellar Sonata for an amplified acoustic harp. When searching for the solutions, I try to come as closely to the sound of an actual electroacoustic harp, while still having the best sound quality in the sense that we hear best the sound of an acoustic harp. There’s a couple of different options of microphones that one can choose from: external microphones or contact microphones. 


External Microphones

This is the most basic means of amplification. External microphones are great for capturing the ambiance of a space along with the sound of the instrument, which means it’s often used for recordings. 

External microphones pick up the sound waves rather than vibration, meaning that it can pick up more sounds than just the sound that the instrument produces. This can pose a problem when it comes to performing a piece as complex as the Stellar Sonata, or any other form of high use of electronic music. 


Contact Microphones

Below are listed some options for contact microphones to amplify the harp, both permanent and non-permanent. I used two different types of contact microphones in my experiments, the piezo's at the very start, and shortly after switching top the AKG Contact microphones. 

Dusty Strings Kit

The Dusty String Kit is a microphone kit that can be built into an acoustic harp. They sell sets for both pedal- and lever harps. The kit includes four microphones that need to be glued into the inside of the soundbox on the soundboard. A mount for a jack cable is installed in the lowest sound hole at the back of the harp, allowing for easy connection. This is a method for quick and easy amplification.


The microphones in this kit need to be permanently glued on the inside. In my experimental research, I found that I preferred the sound when having microphones on the outside of the harp, on the soundboard. The justification for this can be found below. Having the microphones outside obtains the most natural, outward sound of the harp. Besides this, inside the soundbox, the amount of resonance is even greater, making the sound that is picked up less precise.

Furthermore, since all four microphones are connected to one jack cable, there is no possibility of having control on the output of the separate registers, which I found to be rather useful. 

And finally, the set is still 550 euros, so not cheap for an option that is not the ideal solution.


Piezo pieces Contact Microphones

A piezo contact microphones is a small metal disc that translates vibrations from a physical surface into voltage. The piezo discs are made up of a layer of crystal in the centre, surrounded by thin brass. When the piezo comes in contact with a vibrating surface, the disc bends, creating a small electric signal that it sends to the connecting device.4 

 

When I started out working on the recreation of the Stellar Sonata, I initially bought four piezo contact microphones. They were cheap, only 40 euros for the four, easy to find and a good way to start with figuring out what I needed exactly.

The fact that the microphones are on the cheaper end, is highly reflected in the sound quality. After experimenting with these microphones for a while, I decided that the sound quality was definitely not good enough for the sound quality that the Stellar Sonata requires. The sound of the harp amplified in this way looses a lot of its clarity and sweetness. It sounds harsh and not like the natural sound of the harp.

 

 



AKG Contact Microphones

The integrated condenser capsule of these microphones will reproduce the sound of the instrument clearly and without changing the colour or timbre. 

The Audio frequency bandwidth of these microphones is very broad, ranging from 10 to 18000 Hz, which is almost the same as our hearing ear, and much higher than the Piezo contact microphones, explaining the difference in sound quality that the microphones pick up.5  


These high-end contact microphones are 160 euros each. This is of course not inexpensive, but for the sound quality it provides, these microphones are worth the investment. They capture the natural sound of the harp, especially when placed outside on the soundboard. When two microphones are used, it allows for some control over the registers when placed in the right position. This means that when one is placed at the low register of the harp, where the bass notes are, and another along the middle and high register, it allows the user the balance these registers in the sound projection. This is very useful in recreating the sound of an electroacoustic harp, since that one can have a lot of power in the basses. The mid-low and low register of the harp is a register that naturally has trouble with coming out in sound compared to the high register, and thus the control of the registers allow for the same boosting of the lower registers as can be done with the electroacoustic harp.


During my research I have used mostly two microphones, which is definitely enough when it comes to amplifying the harp.


One downside of this method of harp amplification is that the AKG microphones are very sensitive. This is also their strongpoint of course, but in practice this means that they pick up sounds that normally you wouldn’t necessarily want amplified. Examples of this are the noise of the pedal changes and unintentional tapping on the soundboard. These sounds are also amplfied by the microphones and so one has to take extra care of these particular noises when playing. 


Comparing the microphones

During the period of my research, I have done several experiments on how to amplify an acoustic harp. The details of these sessions can be found in the Logbook. 

In this section I would like to showcase the results of the microphone experiments and compare them with each other in sound. 


I have recorded these videos with an iPhone 15. This might not be the most precise means of recording, but if the difference can be heard in these videos, one can imagine what the difference is like in real life. 

 

In this first video a short excerpt from the first movement of the Stellar Sonata is played. The harp is not amplified in this fragment, so this is what it sounds like acoustically. We could say that this video counts as a baseline measurement.


In this second video, the same excerpt from the first movement is played, but this time amplified with Piezo Contact Microphones. The Reverb effect is turned on, as is necessary for this part of the Sonata. We can hear that the sound of the amplification is not ideal. It is quite dry and the harp loses its natural warmth and sparkle.  

Here the same excerpt is demonstrated but amplified with AKG Contact Microphones and with the Reverb effect on. The microphones are in the same position as in the previous example. The quality of the amplification of these microphones is much improved, since it sounds like a natural extension of the harp itself. It doesn't lose clarity or warmth like with the Piezo Contact Microphones

Because of the significant difference in quality between the Piezo Contact Microphone and the AKG Contact Microphone, I chose to work with the AKGs. Of course, there is a difference in price between the two types, but I felt the price-quality difference was worth it in this case. Therefore, from now on any videos made in the context of this research uses the AKG Contact Microphones.

The placement of the Microphones

For this section I have recorded the same excerpt of the Stellar Sonata, from bar 81 till the end of the first movement, each time with the microphones placed in a different position on the harp.  In comparing the excerpts, we can see how the position affects the sound of the amplification. 

I give for each position a video recorded on iPhone 15, and also the sound recording of the AKG Contact microphones itself. Some details can be better heard in the recordings of the microphones than in the videos, but I still wanted to include the videos to show how the differences can be perceived by an audience, which of course can be heard better in real life than on the iPhone recording. 


For each recording, the microphones are placed at different registers of the harp. I found that placing the microphones at different registers gave me some control over balancing the volume of these registers on my audio interface. The electroacoustic harp has quite a large sound in its amplification of the basses and separating the microphones like this made is possible for me to let more bass come through. In general, the top registers of the harp can be very piercing in sound and always come through, so I put the microphone in that register on a lower volume. Each recording uses the Reverb effect.

Position A

The first position if the microphones is on the outside, in the middle of the soundboard. Microphone 1 is placed on the lower left side, beside the F of the 4th octave. Microphone 2 is placed next to the middle/high register, at the height of the C of the 2nd octave. 

 

Listening to the result, I find that the sound of the harp is warm and pleasant. It sounds like the natural resonance of the harp. 

 

Position B

Here I perform the same excerpt, with the same effect on, but with the microphones placed inside the soundbox of the harp. Microphone 1 is in the same position of the lower left and Microphone 2 on the mid/high register. 

 

 

 

In these recordings, we can hear a significant amount more feedback. This is due to the microphones being on the inside of the soundbox. Here, the soundwaves reflect in different direction which is picked up by the microphones. In this way, the resonance of the harp interferes with its own sound, causing problems in the amplification and the added effect. The result is a less clean and clear sound, that is harsher in tone. I had to lower the levels of the microphones because the sound was so loud and harsh compared to position A. 

Position C

Here the microphones are placed on the outside of the soundbox, but not on the back of the harp. Microphone 1 is again in the low register, and microphone 2 in the mid/high. 

 

The sound is much more nasal than in either A or B. It's not as harsh as B or with as much feedback, but the harp loses a lot of its warmness and natural resonance with this placement of microphones. 

Besides this, I found that this placement was particularly uncomfortable as a player. As can be heard in the beginning of the recording, I hit one of the microphones with my knee because they are placed exactly where the knees hold the harp. The most important factor of these experiments is the sound quality, but I felt it important to also mention the comfort level of the player. 

Position D


In this last position, the microphones are in the same position as A, but placed closer to the strings, against the bridge in the middle of the soundboard.

 

The sound difference is the most subtle compared to A out of all the positions. What strikes the most is how much the attack of the string is reflected in the amplification, because of the proximity to it. This makes the amplification again harsh at times, especially in more forte passages with substantial chords. Besides this, we hear some sort of background noise. The other recordings did not have this, so this must be down to the placement of the mics, though I'm unsure of the explanation of where it came from. 

Conclusion placement:

All in all, there's some differences between the different positions.

For me, Position A produced the most natural warm harp sound, with the least amount of feedback and background noises. This is why I have chosen to maintain Position A as the placement for my microphones. When working on recreating the effects in Ableton Live, this is the placement that I have used. 

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