Exploring Experimental Harp Design: Transfer Functions and Acoustic Modification
3 min read
This video documents the iterative process of building and modifying a custom harp. The creator explores how changes to the instrument's physical structure (the transfer function) and the addition of components like springs impact its sonic characteristics. Through acoustic testing and the use of contact microphones, the creator analyzes the instrument's resonance and the challenges of managing mechanical vibrations.
Key takeaways
- Modifying the transfer function of a device by changing its physical structure significantly alters its sonic output.
- Using a combination of acoustic recording and contact microphones provides a better understanding of how individual components contribute to the overall sound.
- Physical modifications, such as adding layers of springs, can create massive sustain and unique acoustic textures.
- The L-shape profile and mounting hardware play a crucial role in the resonance and potential buzzing issues of the instrument.
- Experimental instrument building often involves a process of trial and error, where physical stresses on components can lead to unexpected results or damage.
Exploring the Transfer Function in Instrument Design
The creator explores the concept of the transfer function in the context of a custom-built harp. By modifying the physical structure—specifically removing parts and altering the frame—the creator observes how even small changes to this "transfer function" propagate throughout the entire instrument, drastically changing its sonic character. The goal is to see how much of the original form can be stripped away while still maintaining an interesting sound.
The current iteration features an L-shape profile with pre-made holes for M6 bolts. This structure is intended to be minimalist, yet it faces challenges like buzzing from the tuning pegs, which the creator plans to address with a more secure head design. Despite these technical hurdles, the instrument remains a focal point for experimentation.
Enhancing Sustain Through Physical Modification
A significant addition to the project is a massive layer of springs, which drastically increases the sustain of the instrument. This modification results in a sound described as "big, dark, and transparent." The springs serve as a key component in shaping the instrument's resonance, adding a rich, complex texture that was absent in earlier versions.
Acoustic Testing and Recording Techniques
To evaluate the sound, the creator uses a bow on the strings and positions a microphone approximately 15 cm from the center of the harp. This setup captures the raw acoustic output, revealing nuances in the sound, including unwanted mechanical buzzes from the tuning pegs. Damping the spring assembly helps eliminate these vibrations, demonstrating the importance of physical isolation in acoustic design.
Integrating Contact Microphones and Reverb Units
The experiment extends to integrating a contact microphone and a reverb unit. By connecting the harp directly to a reverb unit, the creator achieves a distinct acoustic effect. Adding a contact microphone allows for a deeper analysis of the sound, revealing how different elements—like the profile and the strings—contribute to the overall mix. This hybrid approach of using both air-based and contact recording helps isolate the sonic contributions of specific components, providing a clearer picture of the instrument's complex acoustic profile.
Timestamps
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00:01Oh my god. Oh my god. Have I Have I ruined the harp? Have I Have I ruined the harp? Have I Have I ruined the harp? Do I have to redo everything again? The other thing I would like to talk The other thing I would like to talk about today is the is the transfer about today is the is the transfer about today is the is the transfer function. function. function. We kind of mentioned that earlier with We kind of mentioned that earlier with We kind of mentioned that earlier with with the cube itself when it was a solid with the cube itself when it was a solid
00:44with the cube itself when it was a solid piece and I was just saying that yeah, piece and I was just saying that yeah, piece and I was just saying that yeah, everything that is going through the everything that is going through the everything that is going through the cube has the character of a cube, cube has the character of a cube, cube has the character of a cube, has the features of a cube and that is has the features of a cube and that is has the features of a cube and that is good and bad simultaneously. good and bad simultaneously. good and bad simultaneously. So, So, So, I we we decided well, we we lost the I we we decided well, we we lost the
01:02I we we decided well, we we lost the wall, one of the fourth, wall, one of the fourth, wall, one of the fourth, and then the journey began because then and then the journey began because then and then the journey began because then by changing by changing by changing one quarter of this transfer function of one quarter of this transfer function of one quarter of this transfer function of this whole thing this whole thing this whole thing as I mentioned earlier changed as I mentioned earlier changed as I mentioned earlier changed everything. everything. everything. But now I kind of got more and more But now I kind of got more and more But now I kind of got more and more curious about
01:23curious about curious about how far can I go with this, how far can I go with this, how far can I go with this, you know, and how little of a cube can you know, and how little of a cube can you know, and how little of a cube can stay stay stay on the table and still be interesting. A lads. A lads. I mean
01:51I mean if we had I mean if we had the cube before, the cube before, the cube before, now this is a corner. now this is a corner. now this is a corner. No, I mean No, I mean No, I mean it's a combo. It's a combo. So, I got to it's a combo. It's a combo. So, I got to it's a combo. It's a combo. So, I got to just turn around so you can see what is just turn around so you can see what is just turn around so you can see what is happening in the inside because that is happening in the inside because that is happening in the inside because that is very handy, right? very handy, right? very handy, right? Look at that. Look at that beauty. Look at that. Look at that beauty.
02:10Look at that. Look at that beauty. Ooh, Ooh, Ooh, my god, that looks good. my god, that looks good. my god, that looks good. Oh, can I actually play it like that?
02:25Yeah, nothing stops me. It's not as Yeah, nothing stops me. It's not as comfortable, but yeah, I can do that. comfortable, but yeah, I can do that. comfortable, but yeah, I can do that. So, what we have here So, what we have here So, what we have here is
02:37the harp that we already know, right? the harp that we already know, right? Because well, not much has changed. I Because well, not much has changed. I Because well, not much has changed. I took off one of the strings because it took off one of the strings because it took off one of the strings because it got loose. As I was saying, it was a set got loose. As I was saying, it was a set got loose. As I was saying, it was a set of old strings, so of old strings, so of old strings, so I don't mind completely. I don't mind completely. I don't mind completely. I just wait for the I just wait for the I just wait for the for update of the head for update of the head
02:57for update of the head where the tuning pegs are so I can um where the tuning pegs are so I can um where the tuning pegs are so I can um put a more or less locked head and then put a more or less locked head and then put a more or less locked head and then let it uh let it uh let it uh not buzz. Most importantly, don't buzz. not buzz. Most importantly, don't buzz. not buzz. Most importantly, don't buzz. As you can see, probably, As you can see, probably, As you can see, probably, it is a fairly basic L-shape
03:26L-shape profile L-shape profile uh with already pre-made holes. They're uh with already pre-made holes. They're uh with already pre-made holes. They're slightly big for the M6 bolts, slightly big for the M6 bolts, slightly big for the M6 bolts, but it's fine because I have but it's fine because I have but it's fine because I have an urge need to see what's going to an urge need to see what's going to an urge need to see what's going to happen if I put happen if I put happen if I put uh more springs because I ordered more uh more springs because I ordered more uh more springs because I ordered more springs. As you can see, even more than springs. As you can see, even more than
03:49springs. As you can see, even more than the the the earlier version. earlier version. earlier version. I have a massive layer of springs here. I have a massive layer of springs here. I have a massive layer of springs here. They give They give They give huge sustain. Huge. huge sustain. Huge. huge sustain. Huge. It's just It's just It's just big, dark, transparent, big, dark, transparent, big, dark, transparent, very beautiful, very beautiful, very beautiful, just amazing. So, just amazing. So, just amazing. So, my question was, what if I just contact my question was, what if I just contact my question was, what if I just contact this reverb unit, only reverb, to the
04:19this reverb unit, only reverb, to the this reverb unit, only reverb, to the to the harp. Actually, since we already to the harp. Actually, since we already to the harp. Actually, since we already have in this like acoustic setup have in this like acoustic setup have in this like acoustic setup checkup, let's start with this, okay? checkup, let's start with this, okay? checkup, let's start with this, okay? So, So, So, what I'm going to do is I'm going to what I'm going to do is I'm going to what I'm going to do is I'm going to take a bow, take a bow, take a bow, cuz I need a bow for this one. I want to cuz I need a bow for this one. I want to
04:35cuz I need a bow for this one. I want to have a bow.
04:59Just this mic in this position. It's not Just this mic in this position. It's not even close. Let's bring it closer.
05:12It is about 15 cm from the center. It's It is about 15 cm from the center. It's uh picking up both sides. uh picking up both sides. uh picking up both sides. And let's hear how would it sound. You hear these buzz? You hear these buzz? Those are tuning pegs. And this is Those are tuning pegs. And this is Those are tuning pegs. And this is annoying.
05:54>> And then if I >> And then if I damp this damp this damp this string springs, that's it. It's gone. string springs, that's it. It's gone. string springs, that's it. It's gone. Then we have Oh, brother. Then we have Oh, brother. Then we have Oh, brother. Just by attaching it with two bolts Just by attaching it with two bolts Just by attaching it with two bolts with washers.
06:14Just attaching the harp to the reverb Just attaching the harp to the reverb unit. I get this acoustically. acoustically. What if we add a contact mic? What if we add a contact mic? What if we add a contact mic? Here it is. Here it is. Here it is. We add in the contact mic first to the We add in the contact mic first to the We add in the contact mic first to the harp. harp.
06:33harp. And it's going to be in the mix already. Oh. Oh. The tail is so beautiful. I'm sorry. The tail is so beautiful. I'm sorry. The tail is so beautiful. I'm sorry. Um now it's time to attach it to the Um now it's time to attach it to the Um now it's time to attach it to the profile. profile. profile. There it There it There it go. go.
07:17go. So now we have the mic pointing in the So now we have the mic pointing in the So now we have the mic pointing in the middle, the contact mic attached to the middle, the contact mic attached to the
07:22middle, the contact mic attached to the profile with the reverb.
08:43And let's actually also play the same uh And let's actually also play the same uh tune that we had with a spring, but I'm tune that we had with a spring, but I'm tune that we had with a spring, but I'm attaching this with strings and a bow. attaching this with strings and a bow. attaching this with strings and a bow. But I'm attaching it to this plate, and But I'm attaching it to this plate, and But I'm attaching it to this plate, and it's supposed to give also slightly it's supposed to give also slightly
08:54it's supposed to give also slightly different balance.
10:17>> Long story short, >> Long story short, I hope it gives you the a bit of an I hope it gives you the a bit of an I hope it gives you the a bit of an understanding how
10:27how these units are sounding how these units are sounding on a separately. And I mean, it is kind on a separately. And I mean, it is kind on a separately. And I mean, it is kind of impossible to get an understanding of of impossible to get an understanding of of impossible to get an understanding of that if we just using the contact mic that if we just using the contact mic that if we just using the contact mic and we are unable to spot and we are unable to spot and we are unable to spot a an actual acoustical difference, not a an actual acoustical difference, not a an actual acoustical difference, not just a transfer function, but the just a transfer function, but the
10:44just a transfer function, but the acoustical difference of like certain acoustical difference of like certain acoustical difference of like certain elements elements elements uh more or less isolated, and that is uh more or less isolated, and that is uh more or less isolated, and that is interesting in my opinion. Oh my god. Oh my god. What I'm looking right now is the the What I'm looking right now is the the What I'm looking right now is the the reason my attention is here. I just put reason my attention is here. I just put reason my attention is here. I just put this corner down this corner down this corner down and it grabbed my attention that
11:11it has bended disgustingly, especially it has bended disgustingly, especially the part that it's attached to the the part that it's attached to the the part that it's attached to the corner. corner. corner. Look what happens to it. I'm going to
11:35It is no It is no bandit. Oh
11:44Have I Have I ruined the harp? Have I Have I ruined the harp? Do I have to redo everything again?
