Збирач потоків

When enclosure size and airflow constraints limit traditional bass‑reflex designs, passive radiators offer a smarter path to deep, controlled low‑frequency performance.

Audio engineers face a persistent challenge—delivering deep bass extension in compact, space‑constrained enclosures without resorting to unwieldy ports that introduce turbulence and design compromises. 

To address this, many have shifted from traditional bass‑reflex systems toward passive radiator (drone cone) topologies, which replace long ports with diaphragm‑based tuning elements that achieve low‑frequency response more efficiently.

This post will explore the mechanics of passive radiators, weigh their trade‑offs, and outline how to select the right approach for your next build.

How passive radiators work

At the heart of any passive radiator system lies the active driver, the true motor of the enclosure, converting amplifier power into acoustic energy. Its displacement dictates how much air is moved inside the box, setting the stage for low‑frequency behaviour.

Opposite to it sits the passive radiator—the drone cone—which visually resembles a standard loudspeaker but omits the voice coil and magnet. Instead, it functions as a mass‑loaded resonator: the trapped air volume inside the enclosure acts like a spring, driving the radiator in sympathy with the active driver’s motion to extend bass response without the turbulence of long ports.

Passive radiator vs. ported designs

When engineers weigh passive radiators against traditional bass‑reflex ports, the trade‑offs become clear. Passive radiators enable more compact enclosures by eliminating the need for long, tuned ports, and they completely sidestep the issue of turbulent airflow and audible chuffing at high excursions.

Their response carries a perceptibly steeper roll-off below tuning due to the compliance notch at the radiator’s free-air resonance, demanding careful tuning and mass adjustment to achieve the desired performance. By contrast, ported designs typically require larger internal volume to accommodate the port and maintain smooth airflow, and while they risk turbulence at higher levels, their fourth‑order roll‑off often produces a more gradual, natural decay.

Ports are also simpler to implement, relying on standard tubing or slot dimensions, whereas passive radiators introduce greater design complexity but reward it with noise‑free operation and space efficiency. In practice, when a purpose‑built speaker is paired with a matching passive radiator, its low‑frequency performance can extend nearly an octave deeper—delivering exceptional bass response without the added space or turbulence of a tuned vent.

Figure 1 A comparison of bass roll‑off profiles shows the passive radiator dropping more sharply (~30 dB/octave) below tuning than the ported system (~24 dB/octave). It explain that the radiator’s steeper slope comes from the acoustic notch at free‑air resonance, while both remain 4th‑order high‑pass alignments in theory. Source: Author

Critical design considerations for builders

Designing with passive radiators demands careful attention to tuning and balance. The system’s tuning frequency can be adjusted by adding or subtracting weight from the radiator’s cone, a straightforward but crucial step in aligning low‑frequency response with the enclosure’s goals.

Many builders refine this further by attaching extra mass directly to the cone, a technique that shifts the resonance frequency with precision and allows deeper bass extension without altering cabinet dimensions—though care must be taken to avoid over‑loading the driver and reducing efficiency.

Figure 2 A passive radiator with an easily adjustable mass enables the design of extremely compact speaker systems capable of incredibly low-frequency output. Source: Dayton Audio

Equally important is the volume compliance ratio (δ), where the passive radiator’s displacement volume should be 1.5 to 2 times greater than that of the active driver, ensuring efficient energy transfer and preventing the radiator from bottoming out. Finally, builders often employ dual passive radiators mounted on opposing sides of the cabinet, a technique that cancels mechanical reaction forces and stabilizes the enclosure. This vibration‑cancellation approach has become especially popular in portable Bluetooth speakers, where compact form factors and mechanical stability are paramount.

Chamber considerations

Every passive radiator system relies on the enclosure chamber as the “spring” that drives the radiator. The trapped air volume inside the cabinet provides the restoring force, so the chamber size must be carefully matched to the driver and radiator parameters. Too small a chamber can raise the tuning frequency and limit bass extension, while too large a chamber can reduce control and efficiency.

In practice, builders balance chamber volume against radiator size and mass, ensuring the compliance of the air spring complements the driver’s displacement. This makes chamber design just as critical as cone mass or compliance ratio when aiming for clean, extended low‑frequency performance.

At its core, the passive radiator system is simply another expression of the Helmholtz resonator principle. In a ported design, the mass of air in the port oscillates against the compliance of the chamber air, producing resonance at the tuned frequency.

With a passive radiator, the cone itself replaces the air column, acting as the moving mass while the trapped air in the enclosure remains the spring. This substitution preserves the Helmholtz effect but eliminates turbulent airflow, enabling deeper bass extension in compact cabinets without the drawbacks of long ports (port tubes).

Figure 3 Large-diameter port tubes optimize bass response in the active resonator circuit but increase enclosure volume and introduce air-chuffing distortions that passive radiators inherently avoid. Source: Author

Additional considerations

Beyond the fundamentals, builders should also weigh practical details that shape real‑world performance. Passive radiators generally require greater displacement capacity than the active driver—typically 1.5 to 2 times more—to move sufficient air at low frequencies and avoid bottoming out under load. Excursion limits are equally critical, since radiators can lose control if driven beyond their mechanical capacity.

Designers also watch for unwanted resonance peaks in the mid‑band, often around 1–2 kHz, which can be tamed with damping materials or improved suspension structures. Unlike ports, radiators don’t provide airflow cooling for the driver, so thermal management becomes a factor in high‑power systems. Finally, measurement and simulation tools such as impedance sweeps or modelling software are invaluable for predicting system behavior and ensuring the radiator is properly matched to the enclosure.

Also, accurate parameter testing is vital when integrating passive radiators. What’s more, builders can rely on impedance sweeps, frequency response plots, and excursion measurements to confirm tuning and displacement margins. These tests not only verify that the radiator achieves its intended resonance without bottoming out, but they also expose mid‑band anomalies or thermal limitations. While simulation tools provide useful predictions, hands‑on measurement remains the most reliable way to validate radiator behavior in a real enclosure.

Figure 4 A datasheet snippet outlines the key technical specifications for the passive radiator. Source: PUIaudio

Material choices for passive radiators

The diaphragm material defines how a passive radiator behaves under load. Rubber and elastomer membranes dominate portable designs, offering flexibility, damping, and resistance to moisture. Polymer composites such as ABS or PET provide lightweight stiffness and cost‑effective molding, though they can fatigue under high SPL.

Metal plates—aluminum or steel—deliver precise mass and long‑term stability but add weight and require damping to avoid ringing. Hybrid laminates that combine rubber with metal or fiber composites balance compliance with rigidity, giving engineers a tuneable middle ground. Selecting the right material is ultimately a trade‑off between durability, acoustic control, and the enclosure’s performance goals.

Application matrix

Choosing between a passive radiator and a ported design depends on the priorities of the build. Passive radiators excel in ultra‑compact or battery‑powered Bluetooth speakers, where enclosure space is at a premium and port tubes would be impractically long. They are also favored in subwoofers that demand deep extension without sacrificing internal volume, and in applications where eliminating port turbulence or chuffing is critical.

Ported designs, on the other hand, remain the go‑to for high‑power, high‑SPL systems such as PA speakers, as well as budget‑focused projects where standardized tubing makes tuning straightforward. When enclosure size is not a limiting factor, ports offer a simple, effective solution with predictable performance.

Passive radiators and ported bass‑reflex designs each bring their own strengths to the table—radiators deliver compactness, vibration control, and noise‑free operation, while ports offer simplicity, predictable tuning, and gradual roll‑off at the expense of larger enclosures and potential turbulence. The decision ultimately rests on your design priorities: whether you value space efficiency and acoustic precision, or raw output and ease of implementation.

As you move forward with your projects, think about which trade‑offs align best with your goals. Are you crafting a portable Bluetooth speaker that demands stability and compactness, or a high‑SPL system where simplicity and sheer output dominate? Share your builds and design choices—I’d love to hear how you’re pushing bass performance beyond the port.

T. K. Hareendran is a self-taught electronics enthusiast with a strong passion for innovative circuit design and hands-on technology. He develops both experimental and practical electronic projects, documenting and sharing his work to support fellow tinkerers and learners. Beyond the workbench, he dedicates time to technical writing and hardware evaluations to contribute meaningfully to the maker community.

Related Content

• Cooling high-power LEDs
• Does global warming impact datacenter cooling?
• Liquid cooling fundamentals for high-power electronics

The post Beyond the port: Fundamentals of passive radiators appeared first on EDN.

Heya everyone! I'm Berry a cutesy trans gal! and I created a simple galvanic electrolysis machine from scratch ✨ It runs on a 5V USB power supply (smartphone/power bank/usb brick) , steps up to 30V, and limits current to a safe range (0.13–1.13mA). The total cost of this final interation works out around to roughly less than ₹600 or under $7 Quick specs :3 • Power: 5V USB → XL6009 → 30V • Current range: 0.13–1.13mA (I usually use 0.4–0.6mA) • It uses an LM324 , two 2N2222 , a few resistors, capacitors and two pots! • if built on breadboard then no soldering required Made from really few electronic components ✨ You can check out the whole document about it with the link here https://drive.google.com/drive/folders/1Q0zdHmhQ3L9I2UA0SnqAUSbfd it includes , schematic, parts list, build guide and more!! I also diy-ed the probe holder , and ermm the needle! but that's another thing on itself and not something I would recommend but yeah! I do have a design for a diy probe holder for commercial needles though if anyone is interested in that! If anyone has any questions then feel free to ask them 🫶✨ Edit:- yes i've tried it on myself!! And treated 65+ follicles in my second time using the machine on myself \^\^ r/diyelectrolysis https://cdn.imgchest.com/files/597c77d60eee.jpg [Schematic](https://cdn.imgchest.com/files/3bd2baf37d40.jpg) submitted by /u/BlueberryCultural361 [link] [comments]

Олександр Чорний (05.12.1989 – 13.03.2022) kpi сб, 09/12/2026 - 21:04

💎 Набір до команди «Формула Студент КПІ» kpi сб, 09/12/2026 - 20:49

submitted by /u/AutoModerator
[link] [comments]

submitted by /u/Curious_Deal5981 [link] [comments]

submitted by /u/Linker3000 [link] [comments]

submitted by /u/m4rkw [link] [comments]

CVD Equipment Corp (CVDE) of Central Islip, NY, USA (a designer and maker of chemical vapor deposition, thermal processing, physical vapor transport, gas and chemical delivery control systems, and other equipment and process solutions for developing and manufacturing materials and coatings) has announced a restructuring plan and leadership transition, following a thorough evaluation of strategic alternatives for its CVD equipment business by its board of directors...

Доповідь ректора КПІ ім. Ігоря Сікорського Анатолія Мельниченка на сесії професорсько-викладацького складу 2026 Інформація КП пт, 09/11/2026 - 17:00

Hey guys! I got into electronics and computers during the pandemic, but could not continue it further due to school work (and being a broke 14yo lol). Finally 6 years later I managed to save up and get myself some components to put something together that felt like an actual project. I will be happy to get any feedback! Github link for details submitted by /u/OjasZ [link] [comments]

Reporting the results of its Flight-1 ‘Mission Asimov’, Washington DC-based Besxar (which is developing the manufacturing of advanced semiconductor materials in space) says that, on 5 July, two of its ‘Clipper-class’ canisters flew from Space Launch Complex 40 (SLC-40) at Cape Canaveral Space Force Station in Florida aboard a SpaceX Falcon 9 first-stage booster and were recovered intact after the booster returned to land...

Goldilocks and the Three Bears (and their porridge, beds and chairs) have got nothing on this high voltage design challenge.

Sometimes a client gets into areas of technology that go way over my head, but I manage to pick up a snippet here or there. This is one such case.

The requirement was to create an electron beam for which the beam energy would be precisely known. The measurement technique is diagrammed as follows (Figure 1).

Figure 1 Fairy tales and their application to electron beam energy (if-necessary reference)

Two curved metal channels were arranged in a circular path through which the electron beam was to be directed. Equal but opposite polarity high voltages would be applied as shown. When an electron source was aimed into one end of this structure, the path of that beam, i.e., the beam’s radius of curvature, would vary as a function of the applied high voltages.

By dint of equations that left me in the dust, when the high voltages and beam energy were a proper match, the electron beam would emerge at the output end where it would go on to serve its intended purpose. The beam’s radius of curvature under the electrostatic field would be just right, and the beam energy would be precisely known. If there was a mismatch, the electron beam would impinge instead on one metal plate or the other and not appear at the output.

The high voltage and voltage precision requirements for this thing were quite demanding. The dual power supply we made for this setup went from zero to 25 kV on each side and had a room temperature versus voltage temperature coefficient on the order of 1 ppm per °C.

Happily, it worked very well.

John Dunn is an electronics consultant and a graduate of The Polytechnic Institute of Brooklyn (BSEE) and of New York University (MSEE).

Related Content

• Researchers develop electron-based Airy Beam

The post Electron beam energy appeared first on EDN.

📰 Газета "Київський політехнік" № 29-30 за 2026 (.pdf) Інформація КП пт, 09/11/2026 - 13:56

As systems grow, the knowledge needed to safely change them becomes harder to retrieve quickly, even when the design itself is sound. Models increasingly encode not just algorithms, but also assumptions, trade-offs, and system-level intent that accumulate over time. As ownership changes hands, understanding that intent becomes the bottleneck.

Consider a common engineering handoff: you are new to an existing project and are asked to update the braking system to support a heavier vehicle variant. The system works. The architecture looks intentional. But you were not part of the original design decisions, and before touching anything, you need to understand what is safe to change and why.

Compared to reading thousands of lines of code, being given a model offers a clear advantage. It exposes structure, makes data flow visible, and captures behavior in a form engineers can reason more quickly. For years, this has been a core strength of model-based design.

However, this advantage is now under pressure. Today’s software-defined systems are larger, more interconnected, and built across distributed teams, suppliers, and release cycles. Even with a well-structured model, engineers still need to reconstruct why signals flow a certain way, which subsystems own specific behaviors, which parameters are safe to modify, and where hidden constraints exist.

So, when that context is hard to recover, teams slow down. Review cycles expand. The risk of validation failures or schedule delays increases. This is not because the design is wrong, but because its underlying rationale is difficult to access quickly. Over time, this becomes an engineering scalability problem: critical knowledge lives inside the design but becomes harder to retrieve as systems grow more complex.

The challenge is no longer simply one of scalability, but of how engineers recover that context quickly enough to make the right change. This is the gap that shows up most clearly in engineering handoffs.

Walkthrough: Recover context in the ABS braking model

To see how this challenge appears in practice, consider an anti-lock braking system (ABS) model. The system runs, but the engineer has been asked to update the braking system to support a heavier vehicle variant. Before making that change, engineers first need to understand where the wheel-speed behavior lives and how it interacts with the rest of the design.

Figure 1 ABS demo regulating wheel slip (Desired Relative Slip) via a bang-bang controller (Controller) drives vehicle/brake dynamics (Vehicle Dynamics) with visualization (Visualization). Source: MathWorks

This opens sldemo_absbrake, a model that simulates vehicle dynamics under braking with a bang-bang controller. The example is small enough to follow end to end, but it raises the same questions that appears in production handoffs: What are the major pieces? Where does the behaviour live? Which blocks should be inspected before changing it?

Get the big picture

Start by building a system-level understanding of the model. Before inspecting individual blocks, click “Simulink Copilot Chat” on the “Simulation” tab of the toolstrip, and type: Give me an overview of this model.

Simulink Copilot returns a structured breakdown of the four top-level subsystems (Controller, Vehicle Dynamics, Visualization, and More Info), the high-level signal flow from slip reference to controller to braking dynamics to visualization, and the control strategy: bang-bang control on the slip error. Every block name in the response is a clickable hyperlink, so the explanation remains tied to the model canvas rather than floating apart from it.

Figure 2 Simulink Copilot generates a grounded overview of the open model, with hyperlinks to each subsystem and block. Source: MathWorks

Instead of digging through the model block by block, a working mental map is established. The model’s behaviour, major connections, and the part of the design worth inspecting before making a change are now clear.

Drill into a subsystem

The overview points to “Vehicle Dynamics” as the subsystem that handles braking physics. If a change could affect wheel motion, stopping distance, or slip, that is the area to drill down next. Instead of opening the subsystem and reading every block manually, right-click the “Vehicle Dynamics” block on the canvas and choose “Explain with Simulink Copilot” in the Simulink context menu.

Figure 3 Right-click any block and choose “Explain with Simulink Copilot” for a contextual explanation without typing a prompt. Source: MathWorks

Simulink Copilot generates a contextual explanation of the subsystem: its purpose, its inputs and outputs, and the internal structure that connects tire forces, brake pressure, wheel speed, vehicle speed, and relative slip. This is not a generic block description. It explains how Vehicle Dynamics is connected to this specific design, which is the context needed before deciding what to modify.

Find where a feature lives

Now suppose the design change requires extending or reviewing the wheel-speed calculation. There is no longer a need to start at the top of the model or guess which subsystem owns that behaviour. Ask the question directly: What components handle wheel-speed calculation?

Figure 4 Simulink Copilot identifies the specific blocks that implement wheel-speed calculation, each hyperlinked for one-click navigation. Source: MathWorks

Simulink Copilot returns the specific blocks involved, including sldemo_wheelspeed_absbrake, the integrator that computes wheel angular velocity, and the gain block that converts angular velocity to wheel speed. Each result is hyperlinked to a model element, enabling navigation from a design question to the implementation detail.

What this looks like in practice

Generate an overview, drill down into subsystems, and perform a targeted search: this becomes a repeatable three-step pattern for working with an inherited Simulink model. Start broad enough to understand the architecture, narrow the conversation around the subsystem that owns the behaviour, and then ask targeted questions that lead to the blocks that may need modification.

From there, follow-up questions can move from orientation to change impact:

• How does the bang-bang control strategy work within the context of this model?
• What outputs are visualized during simulation, and how do they reflect braking performance?
• What adjustments can be made to controller parameters to enhance braking response time?

Each response references the model itself: block names, signal paths, subsystem boundaries, and parameter values. The conversation builds on itself, so by the time the first edit is made, the process is no longer based on a disconnected search result. Instead, it provides a model-specific explanation of what the design does, how the relevant pieces fit together, and why they matter to the requested change.

Tips for better handoff questions

• Be specific about scope. “Explain the braking control logic” works better than “explain this model” once the relevant part of the inherited design has been identified.
• State the goal, not just the question. “I need to extend the wheel-speed calculation” gives Simulink Copilot context to focus on the behaviour that is changing.
• Reference blocks by name when possible. “Explain the Sum block labelled slip_error” is more useful than “explain the Sum block” because it anchors the question in the design.
• Use Deeper Insights for questions that require sophisticated reasoning. Reserve the more thorough analysis for decisions about design intent, subsystem responsibilities, or change impact.

Now return to the engineer at the start: you inherited a model, and you were asked to update the braking system to support a heavier vehicle variant, and the risk was not that the model lacked structure. The risk was acting before understanding the intent behind that structure.

A grounded conversation changes that first hour. The architecture can be mapped, the subsystem that owns the behaviour can be inspected, and the relevant blocks can be identified before making the change. That does not replace engineering judgment or validation, but it provides a faster, more defensible way to inform decisions for the next design change.

Amal Jayarajan Phillai is a product manager at MathWorks.

Related Content

• Accelerating development with model-based design
• Model-based design and early verification aid designers
• Early verification and validation using model-based design
• Understanding the specific use cases for Simulink and Stateflow
• Plan strategies for adopting Model-Based Design for embedded applications

The post You just Inherited a Simulink model you have never seen before. Now what? appeared first on EDN.

У КПІ ім. Ігоря Сікорського створено унікальну дослідницьку інфраструктуру TRIUMPH! kpi пт, 09/11/2026 - 12:21

India’s premier video security brand PRAMA showcased advanced security products and smart security solutions for the MSME sector at the first edition of Bharatiya Vyapar Mahotsav (BVM) from August 12-15, 2026 at Bharat Mandapam, New Delhi. At the exhibition, traders, MSMEs, manufacturers, innovators, businesses and other industry stakeholders came together to showcase their products, services, and solutions. The inaugural event was attended by Union Minister for Commerce & Industry Piyush Goyal, Minister of State for Commerce and Industry Jitin Prasada and former Union Minister Smriti Irani along with leaders and representatives from Confederation of All India Traders (CAIT), Swadeshi Jagran Manch and other organisations.

PRAMA management representative said, “The Bharatiya Vyapar Mahostav is a great platform for Pan India Trade bodies and entrepreneurs of MSME sector. The Indian security market is poised for a new growth phase due to the exponential growth of Micro, Small and Medium Enterprises (MSME) sector. MSME sector is the backbone of India’s economy. We are glad to serve the needs of India’s Medium and Small enterprises. We find Bharatiya Vyapar Mahotsav (BVM) event, a highly valuable exhibition platform to connect with the key stakeholders and ecosystem partners. We showcased the latest products and solutions in this expo. We appreciate CAIT’s proactive role in organizing Bharatiya Vyapar Mahotsav event to spur innovation and engagement with key industry stakeholders.”

He further elaborated, “PRAMA, being India’s premier indigenous security brand holds, great significance. The spectacular growth that India security industry has achieved, PRAMA’s evolution as a leading security brand is the manifestation of Indian spirit and ingenuity. We are taking indigenous manufacturing to the next level. We are here to offer best-in-class products with cutting edge technologies that can deliver solutions as per the MSME Sector’s evolving requirements as per the business cases and application scenarios.”

The elaborately designed spacious PRAMA booth was center of attraction for the trade and industry specific visitors. PRAMA booth showcased the latest products and MSME sector’s solutions, including Ai technology, Interactive Display Panel, Perimeter and Defence Solution, Ranginview IP Series with Built-in MiC, Safe City Solution, Transportation Solution, Mobile enforcement Solution, Networking and Transmission and many more.

PRAMA booth displayed the latest video security products, including Ai Solution. PRAMA’s AiSense technology, powered by advanced AI Algorithms, takes surveillance to the next level. This technology intelligently distinguishes people and vehicles from other moving objects, reducing false alarm caused by animals or environmental factors. With AiSense Technology one can focus on the real threats, optimize resources and build on an intelligent security system. The AI Sense Technology can be very helpful in the various application scenarios in the retail segment for the MSME sector.

PRAMA’s Interactive Display Panel (IDP) was displayed at the booth, it is an all-in-one large display panel which integrates features of a computer, whiteboard, and projector, all in one device, making it a versatile tool for education, corporate training and business video conferencing scenarios. It is a great communication and training tool for the MSME sector.

PRAMA’s booth showcased Safe City Solution, which provides sound, stable and reliable public security. It features a suite of advanced technologies and security subsystems to safeguard industries, centralise operations, and integrate security platforms. These integrated technologies enable rapid and effective responses to security needs and events.

Bharatiya Vyapar Mahotsav (BVM) 2026 is India’s largest Make-In-India multi-sectoral trade expo, designed to bring together India’s diverse business ecosystem under one roof, connecting traders, MSMEs, manufacturers, industry leaders, institutions, and policymakers from across the country. The mega event was organized by Confederation of All India Traders (CAIT) & ITPO.

The Bharatiya Vyapar Mahotsav (BVM), 2026 was a four day event, which was successfully concluded. The event helped to create awareness about the latest innovations and products in the myriad trade segments. The discussions and deliberations were done with various key stakeholders on the core trade and MSME issues. The event was attended by the key trade and business professionals, Government officials and key stakeholders from the Trade and MSME sectors.

The post PRAMA Showcases Smart Security Solutions for MSMEs at Bharatiya Vyapar Mahotsav 2026 appeared first on ELE Times.