A Closer Look at why the Akuasound Source Was a Game-Changer
Today, we want to zoom in on a single component that was absolutely critical to our success: the acoustic source. The choice of source can make or break a field project, and our decision to use the “Akuasound” electrodynamic source was, without a doubt, a game-changer.
Here’s a detailed look at why this specific piece of hardware proved to be the perfect tool for the job.
The Problem with Traditional Tools
In underwater acoustics, piezoelectric transducers are the long-established standard. However, for our goal of creating a portable, low-frequency calibration system, they presented major roadblocks:
Poor Low-Frequency Performance: Piezoelectric sources of a manageable size are inherently less efficient at the low frequencies (e.g., 63 Hz and 125 Hz) crucial for marine noise monitoring. They have a “marked roll-off” in performance, meaning they struggle to produce a strong signal where we need it most.
High Voltage Danger: To compensate for their poor low-frequency response, these sources must be driven with extremely high voltages, often on the order of kilovolts. This is impractical and poses a significant safety risk for personnel operating on a small, wet boat.
Operational Complexity: Many traditional sources require compensation for static pressure as their depth changes, adding another layer of complexity to field operations.
Enter Akuasound: A Paradigm Shift in Performance and Practicality
The Akuasound source, based on a common electrodynamic (loudspeaker) principle, completely sidestepped these issues. It offered a unique combination of advantages that perfectly aligned with our project’s goals.
1. Superior Performance Where It Matters Most
Unlike piezoelectric sources, the Akuasound’s sound emission is essentially constant across the entire human audio band (20 Hz to 20 kHz). For the same input voltage, it delivered a robust and reliable signal at the low frequencies vital for our work. We no longer had to fight against the physics of the tool; we had a source that was naturally gifted in the right range.
2. Unparalleled Safety and Portability
This was perhaps the most significant operational benefit. The Akuasound system operates at a maximum of 36 VDC from a battery pack. This eliminated the need for dangerous high-voltage power supplies and bulky 220V laboratory racks. We replaced an entire rack of equipment with a single, portable flight case, drastically improving safety and simplifying deployment.
3. Simplified Operations and Dramatically Reduced Costs
The Akuasound source offered “significantly simplified operations.” A key feature is that it does not require compensation for static pressure with changes in depth, removing a difficult variable from our fieldwork.
Furthermore, this choice had a major positive impact on the project budget. The selected Akuasound source cost just over €1,000, compared to over €8,000 for the originally specified, more traditional acoustic source. This cost-saving allowed us to allocate resources more effectively elsewhere.
4. Custom-Built for Our Innovative Method
Our groundbreaking measurement method, which uses surface reflection constructively, required a source that could emit sound both upwards and downwards simultaneously. After identifying the potential of the Akuasound, we worked directly with the Italian manufacturer to create an improved model. They developed a version with a dual emission face and dual coils in parallel. This customisation not only enabled our unique geometric setup but also lowered the source’s impedance from 8 to 4 ohms, allowing us to increase the effective power output to around 100 W—more than enough for our field validation.
Conclusion: More Than Just a Component
The Akuasound source wasn’t just a piece of equipment; it was an enabler. It was the key that unlocked the possibility of creating a truly portable, safe, and effective low-frequency calibration system. Its superior performance, operational simplicity, and adaptability were fundamental to the success of the project and form the foundation of the new calibration services we can now offer.
